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Climate variability and change

Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. Climate change may refer to any time in Earth's history, but the term is now commonly used to describe contemporary climate change, often popularly referred to as global warming. Since the Industrial Revolution, the climate has increasingly been affected by human activities.[1]

The climate system receives nearly all of its energy from the sun and radiates energy to outer space. The balance of incoming and outgoing energy and the passage of the energy through the climate system is Earth's energy budget. When the incoming energy is greater than the outgoing energy, Earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and Earth experiences cooling.

The energy moving through Earth's climate system finds expression in weather, varying on geographic scales and time. Long-term averages and variability of weather in a region constitute the region's climate. Such changes can be the result of "internal variability", when natural processes inherent to the various parts of the climate system alter the distribution of energy. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Climate variability can also result from external forcing, when events outside of the climate system's components produce changes within the system. Examples include changes in solar output and volcanism.

Climate variability has consequences for sea level changes, plant life, and mass extinctions; it also affects human societies.

Terminology

Climate variability is the term to describe variations in the mean state and other characteristics of climate (such as chances or possibility of extreme weather, etc.) "on all spatial and temporal scales beyond that of individual weather events." Some of the variability does not appear to be caused by known systems and occurs at seemingly random times. Such variability is called random variability or noise. On the other hand, periodic variability occurs relatively regularly and in distinct modes of variability or climate patterns.[2]

The term climate change is often used to refer specifically to anthropogenic climate change. Anthropogenic climate change is caused by human activity, as opposed to changes in climate that may have resulted as part of Earth's natural processes.[3] Global warming became the dominant popular term in 1988, but within scientific journals global warming refers to surface temperature increases while climate change includes global warming and everything else that increasing greenhouse gas levels affect.[4]

A related term, climatic change, was proposed by the World Meteorological Organization (WMO) in 1966 to encompass all forms of climatic variability on time-scales longer than 10 years, but regardless of cause. During the 1970s, the term climate change replaced climatic change to focus on anthropogenic causes, as it became clear that human activities had a potential to drastically alter the climate.[5] Climate change was incorporated in the title of the Intergovernmental Panel on Climate Change (IPCC) and the UN Framework Convention on Climate Change (UNFCCC). Climate change is now used as both a technical description of the process, as well as a noun used to describe the problem.[5]

Causes

On the broadest scale, the rate at which energy is received from the Sun and the rate at which it is lost to space determine the equilibrium temperature and climate of Earth. This energy is distributed around the globe by winds, ocean currents,[6][7] and other mechanisms to affect the climates of different regions.[8]

Factors that can shape climate are called climate forcings or "forcing mechanisms".[9] These include processes such as variations in solar radiation, variations in the Earth's orbit, variations in the albedo or reflectivity of the continents, atmosphere, and oceans, mountain-building and continental drift and changes in greenhouse gas concentrations. External forcing can be either anthropogenic (e.g. increased emissions of greenhouse gases and dust) or natural (e.g., changes in solar output, the Earth's orbit, volcano eruptions).[10] There are a variety of climate change feedbacks that can either amplify or diminish the initial forcing. There are also key thresholds which when exceeded can produce rapid or irreversible change.

Some parts of the climate system, such as the oceans and ice caps, respond more slowly in reaction to climate forcings, while others respond more quickly. An example of fast change is the atmospheric cooling after a volcanic eruption, when volcanic ash reflects sunlight. Thermal expansion of ocean water after atmospheric warming is slow, and can take thousands of years. A combination is also possible, e.g., sudden loss of albedo in the Arctic Ocean as sea ice melts, followed by more gradual thermal expansion of the water.

Climate variability can also occur due to internal processes. Internal unforced processes often involve changes in the distribution of energy in the ocean and atmosphere, for instance, changes in the thermohaline circulation.

Internal variability

 
There is seasonal variability in how new high temperature records have outpaced new low temperature records.[11]

Climatic changes due to internal variability sometimes occur in cycles or oscillations. For other types of natural climatic change, we cannot predict when it happens; the change is called random or stochastic.[12] From a climate perspective, the weather can be considered random.[13] If there are little clouds in a particular year, there is an energy imbalance and extra heat can be absorbed by the oceans. Due to climate inertia, this signal can be 'stored' in the ocean and be expressed as variability on longer time scales than the original weather disturbances.[14] If the weather disturbances are completely random, occurring as white noise, the inertia of glaciers or oceans can transform this into climate changes where longer-duration oscillations are also larger oscillations, a phenomenon called red noise.[15] Many climate changes have a random aspect and a cyclical aspect. This behavior is dubbed stochastic resonance.[15] Half of the 2021 Nobel prize on physics was awarded for this work to Klaus Hasselmann jointly with Syukuro Manabe for related work on climate modelling. While Giorgio Parisi who with collaborators introduced[16] the concept of stochastic resonance was awarded the other half but mainly for work on theoretical physics.

Ocean-atmosphere variability

The ocean and atmosphere can work together to spontaneously generate internal climate variability that can persist for years to decades at a time.[17][18] These variations can affect global average surface temperature by redistributing heat between the deep ocean and the atmosphere[19][20] and/or by altering the cloud/water vapor/sea ice distribution which can affect the total energy budget of the Earth.[21][22]

Oscillations and cycles

 
Colored bars show how El Niño years (red, regional warming) and La Niña years (blue, regional cooling) relate to overall global warming. The El Niño–Southern Oscillation has been linked to variability in longer-term global average temperature increase.

A climate oscillation or climate cycle is any recurring cyclical oscillation within global or regional climate. They are quasiperiodic (not perfectly periodic), so a Fourier analysis of the data does not have sharp peaks in the spectrum. Many oscillations on different time-scales have been found or hypothesized:[23]

  • the El Niño–Southern Oscillation (ENSO) – A large scale pattern of warmer (El Niño) and colder (La Niña) tropical sea surface temperatures in the Pacific Ocean with worldwide effects. It is a self-sustaining oscillation, whose mechanisms are well-studied.[24] ENSO is the most prominent known source of inter-annual variability in weather and climate around the world. The cycle occurs every two to seven years, with El Niño lasting nine months to two years within the longer term cycle.[25] The cold tongue of the equatorial Pacific Ocean is not warming as fast as the rest of the ocean, due to increased upwelling of cold waters off the west coast of South America.[26][27]
  • the Madden–Julian oscillation (MJO) – An eastward moving pattern of increased rainfall over the tropics with a period of 30 to 60 days, observed mainly over the Indian and Pacific Oceans.[28]
  • the North Atlantic oscillation (NAO) – Indices of the NAO are based on the difference of normalized sea-level pressure (SLP) between Ponta Delgada, Azores and Stykkishólmur/Reykjavík, Iceland. Positive values of the index indicate stronger-than-average westerlies over the middle latitudes.[29]
  • the Quasi-biennial oscillation – a well-understood oscillation in wind patterns in the stratosphere around the equator. Over a period of 28 months the dominant wind changes from easterly to westerly and back.[30]
  • Pacific Centennial Oscillation - a climate oscillation predicted by some climate models
  • the Pacific decadal oscillation – The dominant pattern of sea surface variability in the North Pacific on a decadal scale. During a "warm", or "positive", phase, the west Pacific becomes cool and part of the eastern ocean warms; during a "cool" or "negative" phase, the opposite pattern occurs. It is thought not as a single phenomenon, but instead a combination of different physical processes.[31]
  • the Interdecadal Pacific oscillation (IPO) – Basin wide variability in the Pacific Ocean with a period between 20 and 30 years.[32]
  • the Atlantic multidecadal oscillation – A pattern of variability in the North Atlantic of about 55 to 70 years, with effects on rainfall, droughts and hurricane frequency and intensity.[33]
  • North African climate cycles – climate variation driven by the North African Monsoon, with a period of tens of thousands of years.[34]
  • the Arctic oscillation (AO) and Antarctic oscillation (AAO) – The annular modes are naturally occurring, hemispheric-wide patterns of climate variability. On timescales of weeks to months they explain 20–30% of the variability in their respective hemispheres. The Northern Annular Mode or Arctic oscillation (AO) in the Northern Hemisphere, and the Southern Annular Mode or Antarctic oscillation (AAO) in the southern hemisphere. The annular modes have a strong influence on the temperature and precipitation of mid-to-high latitude land masses, such as Europe and Australia, by altering the average paths of storms. The NAO can be considered a regional index of the AO/NAM.[35] They are defined as the first EOF of sea level pressure or geopotential height from 20°N to 90°N (NAM) or 20°S to 90°S (SAM).
  • Dansgaard–Oeschger cycles – occurring on roughly 1,500-year cycles during the Last Glacial Maximum

Ocean current changes

 
A schematic of modern thermohaline circulation. Tens of millions of years ago, continental-plate movement formed a land-free gap around Antarctica, allowing the formation of the ACC, which keeps warm waters away from Antarctica.

The oceanic aspects of climate variability can generate variability on centennial timescales due to the ocean having hundreds of times more mass than in the atmosphere, and thus very high thermal inertia. For example, alterations to ocean processes such as thermohaline circulation play a key role in redistributing heat in the world's oceans.

Ocean currents transport a lot of energy from the warm tropical regions to the colder polar regions. Changes occurring around the last ice age (in technical terms, the last glacial) show that the circulation is the North Atlantic can change suddenly and substantially, leading to global climate changes, even though the total amount of energy coming into the climate system didn't change much. These large changes may have come from so called Heinrich events where internal instability of ice sheets caused huge ice bergs to be released into the ocean. When the ice sheet melts, the resulting water is very low in salt and cold, driving changes in circulation.[36]

Life

Life affects climate through its role in the carbon and water cycles and through such mechanisms as albedo, evapotranspiration, cloud formation, and weathering.[37][38][39] Examples of how life may have affected past climate include:

External climate forcing

Greenhouse gases

 
CO2 concentrations over the last 800,000 years as measured from ice cores (blue/green) and directly (black)

Whereas greenhouse gases released by the biosphere is often seen as a feedback or internal climate process, greenhouse gases emitted from volcanoes are typically classified as external by climatologists.[50] Greenhouse gases, such as CO2, methane and nitrous oxide, heat the climate system by trapping infrared light. Volcanoes are also part of the extended carbon cycle. Over very long (geological) time periods, they release carbon dioxide from the Earth's crust and mantle, counteracting the uptake by sedimentary rocks and other geological carbon dioxide sinks.

Since the industrial revolution, humanity has been adding to greenhouse gases by emitting CO2 from fossil fuel combustion, changing land use through deforestation, and has further altered the climate with aerosols (particulate matter in the atmosphere),[51] release of trace gases (e.g. nitrogen oxides, carbon monoxide, or methane).[52] Other factors, including land use, ozone depletion, animal husbandry (ruminant animals such as cattle produce methane[53]), and deforestation, also play a role.[54]

The US Geological Survey estimates are that volcanic emissions are at a much lower level than the effects of current human activities, which generate 100–300 times the amount of carbon dioxide emitted by volcanoes.[55] The annual amount put out by human activities may be greater than the amount released by supereruptions, the most recent of which was the Toba eruption in Indonesia 74,000 years ago.[56]

Orbital variations

 
Milankovitch cycles from 800,000 years ago in the past to 800,000 years in the future.

Slight variations in Earth's motion lead to changes in the seasonal distribution of sunlight reaching the Earth's surface and how it is distributed across the globe. There is very little change to the area-averaged annually averaged sunshine; but there can be strong changes in the geographical and seasonal distribution. The three types of kinematic change are variations in Earth's eccentricity, changes in the tilt angle of Earth's axis of rotation, and precession of Earth's axis. Combined, these produce Milankovitch cycles which affect climate and are notable for their correlation to glacial and interglacial periods,[57] their correlation with the advance and retreat of the Sahara,[57] and for their appearance in the stratigraphic record.[58][59]

During the glacial cycles, there was a high correlation between CO2 concentrations and temperatures. Early studies indicated that CO2 concentrations lagged temperatures, but it has become clear that this isn't always the case.[60] When ocean temperatures increase, the solubility of CO2 decreases so that it is released from the ocean. The exchange of CO2 between the air and the ocean can also be impacted by further aspects of climatic change.[61] These and other self-reinforcing processes allow small changes in Earth's motion to have a large effect on climate.[60]

Solar output

 
Variations in solar activity during the last several centuries based on observations of sunspots and beryllium isotopes. The period of extraordinarily few sunspots in the late 17th century was the Maunder minimum.

The Sun is the predominant source of energy input to the Earth's climate system. Other sources include geothermal energy from the Earth's core, tidal energy from the Moon and heat from the decay of radioactive compounds. Both long term variations in solar intensity are known to affect global climate.[62] Solar output varies on shorter time scales, including the 11-year solar cycle[63] and longer-term modulations.[64] Correlation between sunspots and climate and tenuous at best.[62]

Three to four billion years ago, the Sun emitted only 75% as much power as it does today.[65] If the atmospheric composition had been the same as today, liquid water should not have existed on the Earth's surface. However, there is evidence for the presence of water on the early Earth, in the Hadean[66][67] and Archean[68][66] eons, leading to what is known as the faint young Sun paradox.[69] Hypothesized solutions to this paradox include a vastly different atmosphere, with much higher concentrations of greenhouse gases than currently exist.[70] Over the following approximately 4 billion years, the energy output of the Sun increased. Over the next five billion years, the Sun's ultimate death as it becomes a red giant and then a white dwarf will have large effects on climate, with the red giant phase possibly ending any life on Earth that survives until that time.[71]

Volcanism

 
In atmospheric temperature from 1979 to 2010, determined by MSU NASA satellites, effects appear from aerosols released by major volcanic eruptions (El Chichón and Pinatubo). El Niño is a separate event, from ocean variability.

The volcanic eruptions considered to be large enough to affect the Earth's climate on a scale of more than 1 year are the ones that inject over 100,000 tons of SO2 into the stratosphere.[72] This is due to the optical properties of SO2 and sulfate aerosols, which strongly absorb or scatter solar radiation, creating a global layer of sulfuric acid haze.[73] On average, such eruptions occur several times per century, and cause cooling (by partially blocking the transmission of solar radiation to the Earth's surface) for a period of several years. Although volcanoes are technically part of the lithosphere, which itself is part of the climate system, the IPCC explicitly defines volcanism as an external forcing agent.[74]

Notable eruptions in the historical records are the 1991 eruption of Mount Pinatubo which lowered global temperatures by about 0.5 °C (0.9 °F) for up to three years,[75][76] and the 1815 eruption of Mount Tambora causing the Year Without a Summer.[77]

At a larger scale—a few times every 50 million to 100 million years—the eruption of large igneous provinces brings large quantities of igneous rock from the mantle and lithosphere to the Earth's surface. Carbon dioxide in the rock is then released into the atmosphere.[78][79] Small eruptions, with injections of less than 0.1 Mt of sulfur dioxide into the stratosphere, affect the atmosphere only subtly, as temperature changes are comparable with natural variability. However, because smaller eruptions occur at a much higher frequency, they too significantly affect Earth's atmosphere.[72][80]

Plate tectonics

Over the course of millions of years, the motion of tectonic plates reconfigures global land and ocean areas and generates topography. This can affect both global and local patterns of climate and atmosphere-ocean circulation.[81]

The position of the continents determines the geometry of the oceans and therefore influences patterns of ocean circulation. The locations of the seas are important in controlling the transfer of heat and moisture across the globe, and therefore, in determining global climate. A recent example of tectonic control on ocean circulation is the formation of the Isthmus of Panama about 5 million years ago, which shut off direct mixing between the Atlantic and Pacific Oceans. This strongly affected the ocean dynamics of what is now the Gulf Stream and may have led to Northern Hemisphere ice cover.[82][83] During the Carboniferous period, about 300 to 360 million years ago, plate tectonics may have triggered large-scale storage of carbon and increased glaciation.[84] Geologic evidence points to a "megamonsoonal" circulation pattern during the time of the supercontinent Pangaea, and climate modeling suggests that the existence of the supercontinent was conducive to the establishment of monsoons.[85]

The size of continents is also important. Because of the stabilizing effect of the oceans on temperature, yearly temperature variations are generally lower in coastal areas than they are inland. A larger supercontinent will therefore have more area in which climate is strongly seasonal than will several smaller continents or islands.

Other mechanisms

It has been postulated that ionized particles known as cosmic rays could impact cloud cover and thereby the climate. As the sun shields the Earth from these particles, changes in solar activity were hypothesized to influence climate indirectly as well. To test the hypothesis, CERN designed the CLOUD experiment, which showed the effect of cosmic rays is too weak to influence climate noticeably.[86][87]

Evidence exists that the Chicxulub asteroid impact some 66 million years ago had severely affected the Earth's climate. Large quantities of sulfate aerosols were kicked up into the atmosphere, decreasing global temperatures by up to 26 °C and producing sub-freezing temperatures for a period of 3–16 years. The recovery time for this event took more than 30 years.[88] The large-scale use of nuclear weapons has also been investigated for its impact on the climate. The hypothesis is that soot released by large-scale fires blocks a significant fraction of sunlight for as much as a year, leading to a sharp drop in temperatures for a few years. This possible event is described as nuclear winter.[89]

Humans' use of land impact how much sunlight the surface reflects and the concentration of dust. Cloud formation is not only influenced by how much water is in the air and the temperature, but also by the amount of aerosols in the air such as dust.[90] Globally, more dust is available if there are many regions with dry soils, little vegetation and strong winds.[91]

Evidence and measurement of climate changes

Paleoclimatology is the study of changes in climate through the entire history of Earth. It uses a variety of proxy methods from the Earth and life sciences to obtain data preserved within things such as rocks, sediments, ice sheets, tree rings, corals, shells, and microfossils. It then uses the records to determine the past states of the Earth's various climate regions and its atmospheric system. Direct measurements give a more complete overview of climate variability.

Direct measurements

Climate changes that occurred after the widespread deployment of measuring devices can be observed directly. Reasonably complete global records of surface temperature are available beginning from the mid-late 19th century. Further observations are derived indirectly from historical documents. Satellite cloud and precipitation data has been available since the 1970s.[92]

Historical climatology is the study of historical changes in climate and their effect on human history and development. The primary sources include written records such as sagas, chronicles, maps and local history literature as well as pictorial representations such as paintings, drawings and even rock art. Climate variability in the recent past may be derived from changes in settlement and agricultural patterns.[93] Archaeological evidence, oral history and historical documents can offer insights into past changes in the climate. Changes in climate have been linked to the rise[94] and the collapse of various civilizations.[93]

Proxy measurements

 
Variations in CO2, temperature and dust from the Vostok ice core over the last 450,000 years.

Various archives of past climate are present in rocks, trees and fossils. From these archives, indirect measures of climate, so-called proxies, can be derived. Quantification of climatological variation of precipitation in prior centuries and epochs is less complete but approximated using proxies such as marine sediments, ice cores, cave stalagmites, and tree rings.[95] Stress, too little precipitation or unsuitable temperatures, can alter the growth rate of trees, which allows scientists to infer climate trends by analyzing the growth rate of tree rings. This branch of science studying this called dendroclimatology.[96] Glaciers leave behind moraines that contain a wealth of material—including organic matter, quartz, and potassium that may be dated—recording the periods in which a glacier advanced and retreated.

Analysis of ice in cores drilled from an ice sheet such as the Antarctic ice sheet, can be used to show a link between temperature and global sea level variations. The air trapped in bubbles in the ice can also reveal the CO2 variations of the atmosphere from the distant past, well before modern environmental influences. The study of these ice cores has been a significant indicator of the changes in CO2 over many millennia, and continues to provide valuable information about the differences between ancient and modern atmospheric conditions. The 18O/16O ratio in calcite and ice core samples used to deduce ocean temperature in the distant past is an example of a temperature proxy method.

The remnants of plants, and specifically pollen, are also used to study climatic change. Plant distributions vary under different climate conditions. Different groups of plants have pollen with distinctive shapes and surface textures, and since the outer surface of pollen is composed of a very resilient material, they resist decay. Changes in the type of pollen found in different layers of sediment indicate changes in plant communities. These changes are often a sign of a changing climate.[97][98] As an example, pollen studies have been used to track changing vegetation patterns throughout the Quaternary glaciations[99] and especially since the last glacial maximum.[100] Remains of beetles are common in freshwater and land sediments. Different species of beetles tend to be found under different climatic conditions. Given the extensive lineage of beetles whose genetic makeup has not altered significantly over the millennia, knowledge of the present climatic range of the different species, and the age of the sediments in which remains are found, past climatic conditions may be inferred.[101]

Analysis and uncertainties

One difficulty in detecting climate cycles is that the Earth's climate has been changing in non-cyclic ways over most paleoclimatological timescales. Currently we are in a period of anthropogenic global warming. In a larger timeframe, the Earth is emerging from the latest ice age, cooling from the Holocene climatic optimum and warming from the "Little Ice Age", which means that climate has been constantly changing over the last 15,000 years or so. During warm periods, temperature fluctuations are often of a lesser amplitude. The Pleistocene period, dominated by repeated glaciations, developed out of more stable conditions in the Miocene and Pliocene climate. Holocene climate has been relatively stable. All of these changes complicate the task of looking for cyclical behavior in the climate.

Positive feedback, negative feedback, and ecological inertia from the land-ocean-atmosphere system often attenuate or reverse smaller effects, whether from orbital forcings, solar variations or changes in concentrations of greenhouse gases. Certain feedbacks involving processes such as clouds are also uncertain; for contrails, natural cirrus clouds, oceanic dimethyl sulfide and a land-based equivalent, competing theories exist concerning effects on climatic temperatures, for example contrasting the Iris hypothesis and CLAW hypothesis.

Impacts

Life

 
Top: Arid ice age climate
Middle: Atlantic Period, warm and wet
Bottom: Potential vegetation in climate now if not for human effects like agriculture.[102]

Vegetation

A change in the type, distribution and coverage of vegetation may occur given a change in the climate. Some changes in climate may result in increased precipitation and warmth, resulting in improved plant growth and the subsequent sequestration of airborne CO2. The effects are expected to affect the rate of many natural cycles like plant litter decomposition rates.[103] A gradual increase in warmth in a region will lead to earlier flowering and fruiting times, driving a change in the timing of life cycles of dependent organisms. Conversely, cold will cause plant bio-cycles to lag.[104]

Larger, faster or more radical changes, however, may result in vegetation stress, rapid plant loss and desertification in certain circumstances.[105][106] An example of this occurred during the Carboniferous Rainforest Collapse (CRC), an extinction event 300 million years ago. At this time vast rainforests covered the equatorial region of Europe and America. Climate change devastated these tropical rainforests, abruptly fragmenting the habitat into isolated 'islands' and causing the extinction of many plant and animal species.[105]

Wildlife

One of the most important ways animals can deal with climatic change is migration to warmer or colder regions.[107] On a longer timescale, evolution makes ecosystems including animals better adapted to a new climate.[108] Rapid or large climate change can cause mass extinctions when creatures are stretched too far to be able to adapt.[109]

Humanity

Collapses of past civilizations such as the Maya may be related to cycles of precipitation, especially drought, that in this example also correlates to the Western Hemisphere Warm Pool. Around 70 000 years ago the Toba supervolcano eruption created an especially cold period during the ice age, leading to a possible genetic bottleneck in human populations.

Changes in the cryosphere

Glaciers and ice sheets

Glaciers are considered among the most sensitive indicators of a changing climate.[110] Their size is determined by a mass balance between snow input and melt output. As temperatures increase, glaciers retreat unless snow precipitation increases to make up for the additional melt. Glaciers grow and shrink due both to natural variability and external forcings. Variability in temperature, precipitation and hydrology can strongly determine the evolution of a glacier in a particular season.

The most significant climate processes since the middle to late Pliocene (approximately 3 million years ago) are the glacial and interglacial cycles. The present interglacial period (the Holocene) has lasted about 11,700 years.[111] Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level changes helped create the climate. Other changes, including Heinrich events, Dansgaard–Oeschger events and the Younger Dryas, however, illustrate how glacial variations may also influence climate without the orbital forcing.

Sea level change

During the Last Glacial Maximum, some 25,000 years ago, sea levels were roughly 130 m lower than today. The deglaciation afterwards was characterized by rapid sea level change.[112] In the early Pliocene, global temperatures were 1–2˚C warmer than the present temperature, yet sea level was 15–25 meters higher than today.[113]

Sea ice

Sea ice plays an important role in Earth's climate as it affects the total amount of sunlight that is reflected away from the Earth.[114] In the past, the Earth's oceans have been almost entirely covered by sea ice on a number of occasions, when the Earth was in a so-called Snowball Earth state,[115] and completely ice-free in periods of warm climate.[116] When there is a lot of sea ice present globally, especially in the tropics and subtropics, the climate is more sensitive to forcings as the ice–albedo feedback is very strong.[117]

Climate history

Various climate forcings are typically in flux throughout geologic time, and some processes of the Earth's temperature may be self-regulating. For example, during the Snowball Earth period, large glacial ice sheets spanned to Earth's equator, covering nearly its entire surface, and very high albedo created extremely low temperatures, while the accumulation of snow and ice likely removed carbon dioxide through atmospheric deposition. However, the absence of plant cover to absorb atmospheric CO2 emitted by volcanoes meant that the greenhouse gas could accumulate in the atmosphere. There was also an absence of exposed silicate rocks, which use CO2 when they undergo weathering. This created a warming that later melted the ice and brought Earth's temperature back up.

Paleo-eocene thermal maximum

 
Climate changes over the past 65 million years, using proxy data including Oxygen-18 ratios from foraminifera.

The Paleocene–Eocene Thermal Maximum (PETM) was a time period with more than 5–8 °C global average temperature rise across the event.[118] This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs.[119] During the event large amounts of methane was released, a potent greenhouse gas.[120] The PETM represents a "case study" for modern climate change as in the greenhouse gases were released in a geologically relatively short amount of time.[118] During the PETM, a mass extinction of organisms in the deep ocean took place.[121]

The Cenozoic

Throughout the Cenozoic, multiple climate forcings led to warming and cooling of the atmosphere, which led to the early formation of the Antarctic ice sheet, subsequent melting, and its later reglaciation. The temperature changes occurred somewhat suddenly, at carbon dioxide concentrations of about 600–760 ppm and temperatures approximately 4 °C warmer than today. During the Pleistocene, cycles of glaciations and interglacials occurred on cycles of roughly 100,000 years, but may stay longer within an interglacial when orbital eccentricity approaches zero, as during the current interglacial. Previous interglacials such as the Eemian phase created temperatures higher than today, higher sea levels, and some partial melting of the West Antarctic ice sheet.

Climatological temperatures substantially affect cloud cover and precipitation. At lower temperatures, air can hold less water vapour, which can lead to decreased precipitation.[122] During the Last Glacial Maximum of 18,000 years ago, thermal-driven evaporation from the oceans onto continental landmasses was low, causing large areas of extreme desert, including polar deserts (cold but with low rates of cloud cover and precipitation).[102] In contrast, the world's climate was cloudier and wetter than today near the start of the warm Atlantic Period of 8000 years ago.[102]

The Holocene

 
Temperature change over the past 12 000 years, from various sources. The thick black curve is an average.

The Holocene is characterized by a long-term cooling starting after the Holocene Optimum, when temperatures were probably only just below current temperatures (second decade of the 21st century),[123] and a strong African Monsoon created grassland conditions in the Sahara during the Neolithic Subpluvial. Since that time, several cooling events have occurred, including:

In contrast, several warm periods have also taken place, and they include but are not limited to:

Certain effects have occurred during these cycles. For example, during the Medieval Warm Period, the American Midwest was in drought, including the Sand Hills of Nebraska which were active sand dunes. The black death plague of Yersinia pestis also occurred during Medieval temperature fluctuations, and may be related to changing climates.

Solar activity may have contributed to part of the modern warming that peaked in the 1930s. However, solar cycles fail to account for warming observed since the 1980s to the present day.[citation needed] Events such as the opening of the Northwest Passage and recent record low ice minima of the modern Arctic shrinkage have not taken place for at least several centuries, as early explorers were all unable to make an Arctic crossing, even in summer. Shifts in biomes and habitat ranges are also unprecedented, occurring at rates that do not coincide with known climate oscillations[citation needed].

Modern climate change and global warming

As a consequence of humans emitting greenhouse gases, global surface temperatures have started rising. Global warming is an aspect of modern climate change, a term that also includes the observed changes in precipitation, storm tracks and cloudiness. As a consequence, glaciers worldwide have been found to be shrinking significantly.[124][125] Land ice sheets in both Antarctica and Greenland have been losing mass since 2002 and have seen an acceleration of ice mass loss since 2009.[126] Global sea levels have been rising as a consequence of thermal expansion and ice melt. The decline in Arctic sea ice, both in extent and thickness, over the last several decades is further evidence for rapid climate change.[127]

Variability between regions

Global warming has varied substantially by latitude, with the northernmost latitude zones experiencing the largest temperature increases.

In addition to global climate variability and global climate change over time, numerous climatic variations occur contemporaneously across different physical regions.

The oceans' absorption of about 90% of excess heat has helped to cause land surface temperatures to grow more rapidly than sea surface temperatures.[129] The Northern Hemisphere, having a larger landmass-to-ocean ratio than the Southern Hemisphere, shows greater average temperature increases.[131] Variations across different latitude bands also reflect this divergence in average temperature increase, with the temperature increase of northern extratropics exceeding that of the tropics, which in turn exceeds that of the southern extratropics.[132]

Upper regions of the atmosphere have been cooling contemporaneously with a warming in the lower atmosphere, confirming the action of the greenhouse effect and ozone depletion.[133]

Observed regional climatic variations confirm predictions concerning ongoing changes, for example, by contrasting (smoother) year-to-year global variations with (more volatile) year-to-year variations in localized regions.[134] Conversely, comparing different regions' warming patterns to their respective historical variabilities, allows the raw magnitudes of temperature changes to be placed in the perspective of what is normal variability for each region.[136]

Regional variability observations permit study of regionalized climate tipping points such as rainforest loss, ice sheet and sea ice melt, and permafrost thawing.[137] Such distinctions underlie research into a possible global cascade of tipping points.[137]

See also

Notes

  1. ^ America's Climate Choices: Panel on Advancing the Science of Climate Change; National Research Council (2010). . Washington, D.C.: The National Academies Press. ISBN 978-0-309-14588-6. Archived from the original on 29 May 2014. (p1) ... there is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities. While much remains to be learned, the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations. (pp. 21–22) Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities.
  2. ^ Rohli & Vega 2018, p. 274.
  3. ^ "The United Nations Framework Convention on Climate Change". 21 March 1994. from the original on 20 September 2022. Retrieved 9 October 2018. Climate change means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.
  4. ^ "What's in a Name? Global Warming vs. Climate Change". NASA. 5 December 2008. from the original on 9 August 2010. Retrieved 23 July 2011.
  5. ^ a b Hulme, Mike (2016). "Concept of Climate Change, in: The International Encyclopedia of Geography". The International Encyclopedia of Geography. Wiley-Blackwell/Association of American Geographers (AAG): 1. from the original on 29 September 2022. Retrieved 16 May 2016.
  6. ^ Hsiung, Jane (November 1985). "Estimates of Global Oceanic Meridional Heat Transport". Journal of Physical Oceanography. 15 (11): 1405–13. Bibcode:1985JPO....15.1405H. doi:10.1175/1520-0485(1985)015<1405:EOGOMH>2.0.CO;2.
  7. ^ Vallis, Geoffrey K.; Farneti, Riccardo (October 2009). "Meridional energy transport in the coupled atmosphere–ocean system: scaling and numerical experiments". Quarterly Journal of the Royal Meteorological Society. 135 (644): 1643–60. Bibcode:2009QJRMS.135.1643V. doi:10.1002/qj.498. S2CID 122384001.
  8. ^ Trenberth, Kevin E.; et al. (2009). "Earth's Global Energy Budget". Bulletin of the American Meteorological Society. 90 (3): 311–23. Bibcode:2009BAMS...90..311T. doi:10.1175/2008BAMS2634.1.
  9. ^ Smith, Ralph C. (2013). Uncertainty Quantification: Theory, Implementation, and Applications. Computational Science and Engineering. Vol. 12. SIAM. p. 23. ISBN 978-1611973228.
  10. ^ Cronin 2010, pp. 17–18
  11. ^ "Mean Monthly Temperature Records Across the Globe / Timeseries of Global Land and Ocean Areas at Record Levels for October from 1951–2023". NCEI.NOAA.gov. National Centers for Environmental Information (NCEI) of the National Oceanic and Atmospheric Administration (NOAA). November 2023. from the original on 16 November 2023. (change "202310" in URL to see years other than 2023, and months other than 10=October)
  12. ^ Ruddiman 2008, pp. 261–62.
  13. ^ Hasselmann, K. (1976). "Stochastic climate models Part I. Theory". Tellus. 28 (6): 473–85. Bibcode:1976Tell...28..473H. doi:10.1111/j.2153-3490.1976.tb00696.x. ISSN 2153-3490.
  14. ^ Liu, Zhengyu (14 October 2011). "Dynamics of Interdecadal Climate Variability: A Historical Perspective". Journal of Climate. 25 (6): 1963–95. doi:10.1175/2011JCLI3980.1. ISSN 0894-8755. S2CID 53953041.
  15. ^ a b Ruddiman 2008, p. 262.
  16. ^ Benzi R, Parisi G, Sutera A, Vulpiani A (1982). "Stochastic resonance in climatic change". Tellus. 34 (1): 10–6. Bibcode:1982Tell...34...10B. doi:10.1111/j.2153-3490.1982.tb01787.x.
  17. ^ Brown, Patrick T.; Li, Wenhong; Cordero, Eugene C.; Mauget, Steven A. (21 April 2015). "Comparing the model-simulated global warming signal to observations using empirical estimates of unforced noise". Scientific Reports. 5: 9957. Bibcode:2015NatSR...5E9957B. doi:10.1038/srep09957. ISSN 2045-2322. PMC 4404682. PMID 25898351.
  18. ^ Hasselmann, K. (1 December 1976). "Stochastic climate models Part I. Theory". Tellus. 28 (6): 473–85. Bibcode:1976Tell...28..473H. doi:10.1111/j.2153-3490.1976.tb00696.x. ISSN 2153-3490.
  19. ^ Meehl, Gerald A.; Hu, Aixue; Arblaster, Julie M.; Fasullo, John; Trenberth, Kevin E. (8 April 2013). "Externally Forced and Internally Generated Decadal Climate Variability Associated with the Interdecadal Pacific Oscillation". Journal of Climate. 26 (18): 7298–310. Bibcode:2013JCli...26.7298M. doi:10.1175/JCLI-D-12-00548.1. ISSN 0894-8755. OSTI 1565088. S2CID 16183172. from the original on 11 March 2023. Retrieved 5 June 2020.
  20. ^ England, Matthew H.; McGregor, Shayne; Spence, Paul; Meehl, Gerald A.; Timmermann, Axel; Cai, Wenju; Gupta, Alex Sen; McPhaden, Michael J.; Purich, Ariaan (1 March 2014). "Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus". Nature Climate Change. 4 (3): 222–27. Bibcode:2014NatCC...4..222E. doi:10.1038/nclimate2106. ISSN 1758-678X.
  21. ^ Brown, Patrick T.; Li, Wenhong; Li, Laifang; Ming, Yi (28 July 2014). "Top-of-atmosphere radiative contribution to unforced decadal global temperature variability in climate models". Geophysical Research Letters. 41 (14): 2014GL060625. Bibcode:2014GeoRL..41.5175B. doi:10.1002/2014GL060625. hdl:10161/9167. ISSN 1944-8007. S2CID 16933795.
  22. ^ Palmer, M. D.; McNeall, D. J. (1 January 2014). "Internal variability of Earth's energy budget simulated by CMIP5 climate models". Environmental Research Letters. 9 (3): 034016. Bibcode:2014ERL.....9c4016P. doi:10.1088/1748-9326/9/3/034016. ISSN 1748-9326.
  23. ^ "El Niño & Other Oscillations". Woods Hole Oceanographic Institution. from the original on 6 April 2019. Retrieved 6 April 2019.
  24. ^ Wang, Chunzai (2018). "A review of ENSO theories". National Science Review. 5 (6): 813–825. doi:10.1093/nsr/nwy104. ISSN 2095-5138.
  25. ^ Climate Prediction Center (19 December 2005). . National Centers for Environmental Prediction. Archived from the original on 27 August 2009. Retrieved 26 July 2009.
  26. ^ Kevin Krajick. "Part of the Pacific Ocean Is Not Warming as Expected. Why". Columbia University Lamont-Doherty Earth Observatory. from the original on 5 March 2023. Retrieved 2 November 2022.
  27. ^ Aristos Georgiou (26 June 2019). "Mystery Stretch of the Pacific Ocean Is Not Warming Like the Rest of the World's Waters". Newsweek. from the original on 25 February 2023. Retrieved 2 November 2022.
  28. ^ "What is the MJO, and why do we care?". NOAA Climate.gov. from the original on 15 March 2023. Retrieved 6 April 2019.
  29. ^ National Center for Atmospheric Research. Climate Analysis Section. 22 June 2006 at the Wayback Machine Retrieved on 7 June 2007.
  30. ^ Baldwin, M. P.; Gray, L. J.; Dunkerton, T. J.; Hamilton, K.; Haynes, P. H.; Randel, W. J.; Holton, J. R.; Alexander, M. J.; Hirota, I. (2001). "The quasi-biennial oscillation". Reviews of Geophysics. 39 (2): 179–229. Bibcode:2001RvGeo..39..179B. doi:10.1029/1999RG000073. S2CID 16727059.
  31. ^ Newman, Matthew; Alexander, Michael A.; Ault, Toby R.; Cobb, Kim M.; Deser, Clara; Di Lorenzo, Emanuele; Mantua, Nathan J.; Miller, Arthur J.; Minobe, Shoshiro (2016). "The Pacific Decadal Oscillation, Revisited". Journal of Climate. 29 (12): 4399–4427. Bibcode:2016JCli...29.4399N. doi:10.1175/JCLI-D-15-0508.1. ISSN 0894-8755. S2CID 4824093.
  32. ^ "Interdecadal Pacific Oscillation". NIWA. 19 January 2016. from the original on 17 March 2023. Retrieved 6 April 2019.
  33. ^ Kuijpers, Antoon; Bo Holm Jacobsen; Seidenkrantz, Marit-Solveig; Knudsen, Mads Faurschou (2011). "Tracking the Atlantic Multidecadal Oscillation through the last 8,000 years". Nature Communications. 2: 178–. Bibcode:2011NatCo...2..178K. doi:10.1038/ncomms1186. ISSN 2041-1723. PMC 3105344. PMID 21285956.
  34. ^ Skonieczny, C. (2 January 2019). "Monsoon-driven Saharan dust variability over the past 240,000 years". Science Advances. 5 (1): eaav1887. Bibcode:2019SciA....5.1887S. doi:10.1126/sciadv.aav1887. PMC 6314818. PMID 30613782.
  35. ^ Thompson, David. "Annular Modes – Introduction". from the original on 18 March 2023. Retrieved 11 February 2020.
  36. ^ Burroughs 2001, pp. 207–08.
  37. ^ Spracklen, D. V.; Bonn, B.; Carslaw, K. S. (2008). "Boreal forests, aerosols and the impacts on clouds and climate". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 366 (1885): 4613–26. Bibcode:2008RSPTA.366.4613S. doi:10.1098/rsta.2008.0201. PMID 18826917. S2CID 206156442.
  38. ^ Christner, B. C.; Morris, C. E.; Foreman, C. M.; Cai, R.; Sands, D. C. (2008). "Ubiquity of Biological Ice Nucleators in Snowfall" (PDF). Science. 319 (5867): 1214. Bibcode:2008Sci...319.1214C. doi:10.1126/science.1149757. PMID 18309078. S2CID 39398426. (PDF) from the original on 5 March 2020.
  39. ^ Schwartzman, David W.; Volk, Tyler (1989). "Biotic enhancement of weathering and the habitability of Earth". Nature. 340 (6233): 457–60. Bibcode:1989Natur.340..457S. doi:10.1038/340457a0. S2CID 4314648.
  40. ^ Kopp, R.E.; Kirschvink, J.L.; Hilburn, I.A.; Nash, C.Z. (2005). "The Paleoproterozoic snowball Earth: A climate disaster triggered by the evolution of oxygenic photosynthesis". Proceedings of the National Academy of Sciences. 102 (32): 11131–36. Bibcode:2005PNAS..10211131K. doi:10.1073/pnas.0504878102. PMC 1183582. PMID 16061801.
  41. ^ Kasting, J.F.; Siefert, JL (2002). "Life and the Evolution of Earth's Atmosphere". Science. 296 (5570): 1066–68. Bibcode:2002Sci...296.1066K. doi:10.1126/science.1071184. PMID 12004117. S2CID 37190778.
  42. ^ Mora, C.I.; Driese, S.G.; Colarusso, L. A. (1996). "Middle to Late Paleozoic Atmospheric CO2 Levels from Soil Carbonate and Organic Matter". Science. 271 (5252): 1105–07. Bibcode:1996Sci...271.1105M. doi:10.1126/science.271.5252.1105. S2CID 128479221.
  43. ^ Berner, R.A. (1999). "Atmospheric oxygen over Phanerozoic time". Proceedings of the National Academy of Sciences. 96 (20): 10955–57. Bibcode:1999PNAS...9610955B. doi:10.1073/pnas.96.20.10955. PMC 34224. PMID 10500106.
  44. ^ Bains, Santo; Norris, Richard D.; Corfield, Richard M.; Faul, Kristina L. (2000). "Termination of global warmth at the Palaeocene/Eocene boundary through productivity feedback". Nature. 407 (6801): 171–74. Bibcode:2000Natur.407..171B. doi:10.1038/35025035. PMID 11001051. S2CID 4419536.
  45. ^ Zachos, J.C.; Dickens, G.R. (2000). "An assessment of the biogeochemical feedback response to the climatic and chemical perturbations of the LPTM". GFF. 122 (1): 188–89. Bibcode:2000GFF...122..188Z. doi:10.1080/11035890001221188. S2CID 129797785.
  46. ^ Speelman, E.N.; Van Kempen, M.M.L.; Barke, J.; Brinkhuis, H.; Reichart, G.J.; Smolders, A.J.P.; Roelofs, J.G.M.; Sangiorgi, F.; De Leeuw, J.W.; Lotter, A.F.; Sinninghe Damsté, J.S. (2009). "The Eocene Arctic Azolla bloom: Environmental conditions, productivity and carbon drawdown". Geobiology. 7 (2): 155–70. Bibcode:2009Gbio....7..155S. doi:10.1111/j.1472-4669.2009.00195.x. PMID 19323694. S2CID 13206343.
  47. ^ Brinkhuis, Henk; Schouten, Stefan; Collinson, Margaret E.; Sluijs, Appy; Sinninghe Damsté, Jaap S. Sinninghe; Dickens, Gerald R.; Huber, Matthew; Cronin, Thomas M.; Onodera, Jonaotaro; Takahashi, Kozo; Bujak, Jonathan P.; Stein, Ruediger; Van Der Burgh, Johan; Eldrett, James S.; Harding, Ian C.; Lotter, André F.; Sangiorgi, Francesca; Van Konijnenburg-Van Cittert, Han van Konijnenburg-van; De Leeuw, Jan W.; Matthiessen, Jens; Backman, Jan; Moran, Kathryn; Expedition 302, Scientists (2006). "Episodic fresh surface waters in the Eocene Arctic Ocean". Nature. 441 (7093): 606–09. Bibcode:2006Natur.441..606B. doi:10.1038/nature04692. hdl:11250/174278. PMID 16752440. S2CID 4412107.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  48. ^ Retallack, Gregory J. (2001). "Cenozoic Expansion of Grasslands and Climatic Cooling". The Journal of Geology. 109 (4): 407–26. Bibcode:2001JG....109..407R. doi:10.1086/320791. S2CID 15560105.
  49. ^ Dutton, Jan F.; Barron, Eric J. (1997). "Miocene to present vegetation changes: A possible piece of the Cenozoic cooling puzzle". Geology. 25 (1): 39. Bibcode:1997Geo....25...39D. doi:10.1130/0091-7613(1997)025<0039:MTPVCA>2.3.CO;2.
  50. ^ Cronin 2010, p. 17
  51. ^ "3. Are human activities causing climate change?". science.org.au. Australian Academy of Science. from the original on 8 May 2019. Retrieved 12 August 2017.
  52. ^ Antoaneta Yotova, ed. (2009). "Anthropogenic Climate Influences". Climate Change, Human Systems and Policy Volume I. Eolss Publishers. ISBN 978-1-905839-02-5. from the original on 4 April 2023. Retrieved 16 August 2020.
  53. ^ Steinfeld, H.; P. Gerber; T. Wassenaar; V. Castel; M. Rosales; C. de Haan (2006). Livestock's long shadow. from the original on 26 July 2008. Retrieved 21 July 2009.
  54. ^ The Editorial Board (28 November 2015). "What the Paris Climate Meeting Must Do". The New York Times. from the original on 29 November 2015. Retrieved 28 November 2015.
  55. ^ "Volcanic Gases and Their Effects". U.S. Department of the Interior. 10 January 2006. from the original on 1 August 2013. Retrieved 21 January 2008.
  56. ^ . American Geophysical Union. 14 June 2011. Archived from the original on 9 May 2013. Retrieved 20 June 2011.
  57. ^ a b . University of Montana. Archived from the original on 16 July 2011. Retrieved 2 April 2009.
  58. ^ Gale, Andrew S. (1989). "A Milankovitch scale for Cenomanian time". Terra Nova. 1 (5): 420–25. Bibcode:1989TeNov...1..420G. doi:10.1111/j.1365-3121.1989.tb00403.x.
  59. ^ . sdu.dk. University of Denmark. Archived from the original on 12 March 2015.
  60. ^ a b van Nes, Egbert H.; Scheffer, Marten; Brovkin, Victor; Lenton, Timothy M.; Ye, Hao; Deyle, Ethan; Sugihara, George (2015). "Causal feedbacks in climate change". Nature Climate Change. 5 (5): 445–48. Bibcode:2015NatCC...5..445V. doi:10.1038/nclimate2568. ISSN 1758-6798.
  61. ^ Box 6.2: What Caused the Low Atmospheric Carbon Dioxide Concentrations During Glacial Times? 8 January 2023 at the Wayback Machine in IPCC AR4 WG1 2007 .
  62. ^ a b Rohli & Vega 2018, p. 296.
  63. ^ Willson, Richard C.; Hudson, Hugh S. (1991). "The Sun's luminosity over a complete solar cycle". Nature. 351 (6321): 42–44. Bibcode:1991Natur.351...42W. doi:10.1038/351042a0. S2CID 4273483.
  64. ^ Turner, T. Edward; Swindles, Graeme T.; Charman, Dan J.; Langdon, Peter G.; Morris, Paul J.; Booth, Robert K.; Parry, Lauren E.; Nichols, Jonathan E. (5 April 2016). "Solar cycles or random processes? Evaluating solar variability in Holocene climate records". Scientific Reports. 6 (1): 23961. doi:10.1038/srep23961. ISSN 2045-2322. PMC 4820721. PMID 27045989.
  65. ^ Ribas, Ignasi (February 2010). The Sun and stars as the primary energy input in planetary atmospheres. IAU Symposium 264 'Solar and Stellar Variability – Impact on Earth and Planets'. Proceedings of the International Astronomical Union. Vol. 264. pp. 3–18. arXiv:0911.4872. Bibcode:2010IAUS..264....3R. doi:10.1017/S1743921309992298.
  66. ^ a b Marty, B. (2006). "Water in the Early Earth". Reviews in Mineralogy and Geochemistry. 62 (1): 421–450. Bibcode:2006RvMG...62..421M. doi:10.2138/rmg.2006.62.18.
  67. ^ Watson, E.B.; Harrison, TM (2005). "Zircon Thermometer Reveals Minimum Melting Conditions on Earliest Earth". Science. 308 (5723): 841–44. Bibcode:2005Sci...308..841W. doi:10.1126/science.1110873. PMID 15879213. S2CID 11114317.
  68. ^ Hagemann, Steffen G.; Gebre-Mariam, Musie; Groves, David I. (1994). "Surface-water influx in shallow-level Archean lode-gold deposits in Western, Australia". Geology. 22 (12): 1067. Bibcode:1994Geo....22.1067H. doi:10.1130/0091-7613(1994)022<1067:SWIISL>2.3.CO;2.
  69. ^ Sagan, C.; G. Mullen (1972). "Earth and Mars: Evolution of Atmospheres and Surface Temperatures". Science. 177 (4043): 52–6. Bibcode:1972Sci...177...52S. doi:10.1126/science.177.4043.52. PMID 17756316. S2CID 12566286. from the original on 9 August 2010. Retrieved 30 January 2009.
  70. ^ Sagan, C.; Chyba, C (1997). "The Early Faint Sun Paradox: Organic Shielding of Ultraviolet-Labile Greenhouse Gases". Science. 276 (5316): 1217–21. Bibcode:1997Sci...276.1217S. doi:10.1126/science.276.5316.1217. PMID 11536805.
  71. ^ Schröder, K.-P.; Connon Smith, Robert (2008), "Distant future of the Sun and Earth revisited", Monthly Notices of the Royal Astronomical Society, 386 (1): 155–63, arXiv:0801.4031, Bibcode:2008MNRAS.386..155S, doi:10.1111/j.1365-2966.2008.13022.x, S2CID 10073988
  72. ^ a b Miles, M.G.; Grainger, R.G.; Highwood, E.J. (2004). "The significance of volcanic eruption strength and frequency for climate". Quarterly Journal of the Royal Meteorological Society. 130 (602): 2361–76. Bibcode:2004QJRMS.130.2361M. doi:10.1256/qj.03.60. S2CID 53005926.
  73. ^ "Volcanic Gases and Climate Change Overview". usgs.gov. USGS. from the original on 29 July 2014. Retrieved 31 July 2014.
  74. ^ Annexes 6 July 2019 at the Wayback Machine, in IPCC AR4 SYR 2008, p. 58.
  75. ^ Diggles, Michael (28 February 2005). "The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines". U.S. Geological Survey Fact Sheet 113-97. United States Geological Survey. from the original on 25 August 2013. Retrieved 8 October 2009.
  76. ^ Diggles, Michael. "The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines". usgs.gov. from the original on 25 August 2013. Retrieved 31 July 2014.
  77. ^ Oppenheimer, Clive (2003). "Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815". Progress in Physical Geography. 27 (2): 230–59. doi:10.1191/0309133303pp379ra. S2CID 131663534.
  78. ^ Black, Benjamin A.; Gibson, Sally A. (2019). "Deep Carbon and the Life Cycle of Large Igneous Provinces". Elements. 15 (5): 319–324. doi:10.2138/gselements.15.5.319.
  79. ^ Wignall, P (2001). "Large igneous provinces and mass extinctions". Earth-Science Reviews. 53 (1): 1–33. Bibcode:2001ESRv...53....1W. doi:10.1016/S0012-8252(00)00037-4.
  80. ^ Graf, H.-F.; Feichter, J.; Langmann, B. (1997). "Volcanic sulphur emissions: Estimates of source strength and its contribution to the global sulphate distribution". Journal of Geophysical Research: Atmospheres. 102 (D9): 10727–38. Bibcode:1997JGR...10210727G. doi:10.1029/96JD03265. hdl:21.11116/0000-0003-2CBB-A.
  81. ^ Forest, C.E.; Wolfe, J.A.; Molnar, P.; Emanuel, K.A. (1999). "Paleoaltimetry incorporating atmospheric physics and botanical estimates of paleoclimate". Geological Society of America Bulletin. 111 (4): 497–511. Bibcode:1999GSAB..111..497F. doi:10.1130/0016-7606(1999)111<0497:PIAPAB>2.3.CO;2. hdl:1721.1/10809.
  82. ^ . NASA Earth Observatory. Archived from the original on 2 August 2007. Retrieved 1 July 2008.
  83. ^ Haug, Gerald H.; Keigwin, Lloyd D. (22 March 2004). "How the Isthmus of Panama Put Ice in the Arctic". Oceanus. Woods Hole Oceanographic Institution. 42 (2). from the original on 5 October 2018. Retrieved 1 October 2013.
  84. ^ Bruckschen, Peter; Oesmanna, Susanne; Veizer, Ján (30 September 1999). "Isotope stratigraphy of the European Carboniferous: proxy signals for ocean chemistry, climate and tectonics". Chemical Geology. 161 (1–3): 127–63. Bibcode:1999ChGeo.161..127B. doi:10.1016/S0009-2541(99)00084-4.
  85. ^ Parrish, Judith T. (1993). "Climate of the Supercontinent Pangea". The Journal of Geology. The University of Chicago Press. 101 (2): 215–33. Bibcode:1993JG....101..215P. doi:10.1086/648217. JSTOR 30081148. S2CID 128757269.
  86. ^ Hausfather, Zeke (18 August 2017). "Explainer: Why the sun is not responsible for recent climate change". Carbon Brief. from the original on 17 March 2023. Retrieved 5 September 2019.
  87. ^ Pierce, J. R. (2017). "Cosmic rays, aerosols, clouds, and climate: Recent findings from the CLOUD experiment". Journal of Geophysical Research: Atmospheres. 122 (15): 8051–55. Bibcode:2017JGRD..122.8051P. doi:10.1002/2017JD027475. ISSN 2169-8996. S2CID 125580175.
  88. ^ Brugger, Julia; Feulner, Georg; Petri, Stefan (April 2017), "Severe environmental effects of Chicxulub impact imply key role in end-Cretaceous mass extinction", 19th EGU General Assembly, EGU2017, proceedings from the conference, 23–28 April 2017, vol. 19, Vienna, Austria, p. 17167, Bibcode:2017EGUGA..1917167B.{{citation}}: CS1 maint: location missing publisher (link)
  89. ^ Burroughs 2001, p. 232.
  90. ^ Hadlington, Simon 9 (May 2013). "Mineral dust plays key role in cloud formation and chemistry". Chemistry World. from the original on 24 October 2022. Retrieved 5 September 2019.{{cite web}}: CS1 maint: numeric names: authors list (link)
  91. ^ Mahowald, Natalie; Albani, Samuel; Kok, Jasper F.; Engelstaeder, Sebastian; Scanza, Rachel; Ward, Daniel S.; Flanner, Mark G. (1 December 2014). "The size distribution of desert dust aerosols and its impact on the Earth system". Aeolian Research. 15: 53–71. Bibcode:2014AeoRe..15...53M. doi:10.1016/j.aeolia.2013.09.002. ISSN 1875-9637.
  92. ^ New, M.; Todd, M.; Hulme, M; Jones, P. (December 2001). "Review: Precipitation measurements and trends in the twentieth century". International Journal of Climatology. 21 (15): 1889–922. Bibcode:2001IJCli..21.1889N. doi:10.1002/joc.680. S2CID 56212756.
  93. ^ a b Demenocal, P.B. (2001). (PDF). Science. 292 (5517): 667–73. Bibcode:2001Sci...292..667D. doi:10.1126/science.1059827. PMID 11303088. S2CID 18642937. Archived from the original (PDF) on 17 December 2008. Retrieved 28 August 2015.
  94. ^ Sindbaek, S.M. (2007). "Networks and nodal points: the emergence of towns in early Viking Age Scandinavia". Antiquity. 81 (311): 119–32. doi:10.1017/s0003598x00094886.
  95. ^ Dominic, F.; Burns, S.J.; Neff, U.; Mudulsee, M.; Mangina, A; Matter, A. (April 2004). "Palaeoclimatic interpretation of high-resolution oxygen isotope profiles derived from annually laminated speleothems from Southern Oman". Quaternary Science Reviews. 23 (7–8): 935–45. Bibcode:2004QSRv...23..935F. doi:10.1016/j.quascirev.2003.06.019.
  96. ^ Hughes, Malcolm K.; Swetnam, Thomas W.; Diaz, Henry F., eds. (2010). Dendroclimatology: progress and prospect. Developments in Paleoenvironmental Research. Vol. 11. New York: Springer Science & Business Media. ISBN 978-1-4020-4010-8.
  97. ^ Langdon, P.G.; Barber, K.E.; Lomas-Clarke, S.H.; Lomas-Clarke, S.H. (August 2004). "Reconstructing climate and environmental change in northern England through chironomid and pollen analyses: evidence from Talkin Tarn, Cumbria". Journal of Paleolimnology. 32 (2): 197–213. Bibcode:2004JPall..32..197L. doi:10.1023/B:JOPL.0000029433.85764.a5. S2CID 128561705.
  98. ^ Birks, H.H. (March 2003). (PDF). Quaternary Science Reviews. 22 (5–7): 453–73. Bibcode:2003QSRv...22..453B. doi:10.1016/S0277-3791(02)00248-2. hdl:1956/387. Archived from the original (PDF) on 11 June 2007. Retrieved 20 April 2018.
  99. ^ Miyoshi, N; Fujiki, Toshiyuki; Morita, Yoshimune (1999). "Palynology of a 250-m core from Lake Biwa: a 430,000-year record of glacial–interglacial vegetation change in Japan". Review of Palaeobotany and Palynology. 104 (3–4): 267–83. Bibcode:1999RPaPa.104..267M. doi:10.1016/S0034-6667(98)00058-X.
  100. ^ Prentice, I. Colin; Bartlein, Patrick J; Webb, Thompson (1991). "Vegetation and Climate Change in Eastern North America Since the Last Glacial Maximum". Ecology. 72 (6): 2038–56. doi:10.2307/1941558. JSTOR 1941558.
  101. ^ Coope, G.R.; Lemdahl, G.; Lowe, J.J.; Walkling, A. (4 May 1999). "Temperature gradients in northern Europe during the last glacial – Holocene transition (14–9 14 C kyr BP) interpreted from coleopteran assemblages". Journal of Quaternary Science. 13 (5): 419–33. Bibcode:1998JQS....13..419C. doi:10.1002/(SICI)1099-1417(1998090)13:5<419::AID-JQS410>3.0.CO;2-D.
  102. ^ a b c Adams, J.M.; Faure, H., eds. (1997). . Tennessee: Oak Ridge National Laboratory. Archived from the original on 16 January 2008. QEN members.
  103. ^ Ochoa-Hueso, R; Delgado-Baquerizo, N; King, PTA; Benham, M; Arca, V; Power, SA (2019). "Ecosystem type and resource quality are more important than global change drivers in regulating early stages of litter decomposition". Soil Biology and Biochemistry. 129: 144–52. doi:10.1016/j.soilbio.2018.11.009. hdl:10261/336676. S2CID 92606851.
  104. ^ Kinver, Mark (15 November 2011). "UK trees' fruit ripening '18 days earlier'". Bbc.co.uk. from the original on 17 March 2023. Retrieved 1 November 2012.
  105. ^ a b Sahney, S.; Benton, M.J.; Falcon-Lang, H.J. (2010). "Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica" (PDF). Geology. 38 (12): 1079–82. Bibcode:2010Geo....38.1079S. doi:10.1130/G31182.1. from the original on 17 March 2023. Retrieved 27 November 2013.
  106. ^ Bachelet, D.; Neilson, R.; Lenihan, J. M.; Drapek, R.J. (2001). "Climate Change Effects on Vegetation Distribution and Carbon Budget in the United States". Ecosystems. 4 (3): 164–85. doi:10.1007/s10021-001-0002-7. S2CID 15526358.
  107. ^ Burroughs 2007, p. 273.
  108. ^ Millington, Rebecca; Cox, Peter M.; Moore, Jonathan R.; Yvon-Durocher, Gabriel (10 May 2019). "Modelling ecosystem adaptation and dangerous rates of global warming". Emerging Topics in Life Sciences. 3 (2): 221–31. doi:10.1042/ETLS20180113. hdl:10871/36988. ISSN 2397-8554. PMID 33523155. S2CID 150221323.
  109. ^ Burroughs 2007, p. 267.
  110. ^ Seiz, G.; N. Foppa (2007). (PDF) (Report). Archived from the original (PDF) on 25 March 2009. Retrieved 21 June 2009.
  111. ^ . International Commission on Stratigraphy. 2008. Archived from the original on 15 October 2011. Retrieved 3 October 2011.
  112. ^ Burroughs 2007, p. 279.
  113. ^ Hansen, James. . NASA GISS. Archived from the original on 24 July 2011. Retrieved 25 April 2013.
  114. ^ Belt, Simon T.; Cabedo-Sanz, Patricia; Smik, Lukas; et al. (2015). "Identification of paleo Arctic winter sea ice limits and the marginal ice zone: Optimised biomarker-based reconstructions of late Quaternary Arctic sea ice". Earth and Planetary Science Letters. 431: 127–39. Bibcode:2015E&PSL.431..127B. doi:10.1016/j.epsl.2015.09.020. hdl:10026.1/4335. ISSN 0012-821X.
  115. ^ Warren, Stephen G.; Voigt, Aiko; Tziperman, Eli; et al. (1 November 2017). "Snowball Earth climate dynamics and Cryogenian geology-geobiology". Science Advances. 3 (11): e1600983. Bibcode:2017SciA....3E0983H. doi:10.1126/sciadv.1600983. ISSN 2375-2548. PMC 5677351. PMID 29134193.
  116. ^ Caballero, R.; Huber, M. (2013). "State-dependent climate sensitivity in past warm climates and its implications for future climate projections". Proceedings of the National Academy of Sciences. 110 (35): 14162–67. Bibcode:2013PNAS..11014162C. doi:10.1073/pnas.1303365110. ISSN 0027-8424. PMC 3761583. PMID 23918397.
  117. ^ Hansen James; Sato Makiko; Russell Gary; Kharecha Pushker (2013). "Climate sensitivity, sea level and atmospheric carbon dioxide". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 371 (2001): 20120294. arXiv:1211.4846. Bibcode:2013RSPTA.37120294H. doi:10.1098/rsta.2012.0294. PMC 3785813. PMID 24043864.
  118. ^ a b McInherney, F.A..; Wing, S. (2011). "A perturbation of carbon cycle, climate, and biosphere with implications for the future". Annual Review of Earth and Planetary Sciences. 39: 489–516. Bibcode:2011AREPS..39..489M. doi:10.1146/annurev-earth-040610-133431. from the original on 14 September 2016. Retrieved 26 October 2019.
  119. ^ Westerhold, T..; Röhl, U.; Raffi, I.; Fornaciari, E.; Monechi, S.; Reale, V.; Bowles, J.; Evans, H. F. (2008). "Astronomical calibration of the Paleocene time" (PDF). Palaeogeography, Palaeoclimatology, Palaeoecology. 257 (4): 377–403. Bibcode:2008PPP...257..377W. doi:10.1016/j.palaeo.2007.09.016. (PDF) from the original on 9 August 2017.
  120. ^ Burroughs 2007, pp. 190–91.
  121. ^ Ivany, Linda C.; Pietsch, Carlie; Handley, John C.; Lockwood, Rowan; Allmon, Warren D.; Sessa, Jocelyn A. (1 September 2018). "Little lasting impact of the Paleocene-Eocene Thermal Maximum on shallow marine molluscan faunas". Science Advances. 4 (9): eaat5528. Bibcode:2018SciA....4.5528I. doi:10.1126/sciadv.aat5528. ISSN 2375-2548. PMC 6124918. PMID 30191179.
  122. ^ Haerter, Jan O.; Moseley, Christopher; Berg, Peter (2013). "Strong increase in convective precipitation in response to higher temperatures". Nature Geoscience. 6 (3): 181–85. Bibcode:2013NatGe...6..181B. doi:10.1038/ngeo1731. ISSN 1752-0908.
  123. ^ Kaufman, Darrell; McKay, Nicholas; Routson, Cody; Erb, Michael; Dätwyler, Christoph; Sommer, Philipp S.; Heiri, Oliver; Davis, Basil (30 June 2020). "Holocene global mean surface temperature, a multi-method reconstruction approach". Scientific Data. 7 (1): 201. Bibcode:2020NatSD...7..201K. doi:10.1038/s41597-020-0530-7. ISSN 2052-4463. PMC 7327079. PMID 32606396.
  124. ^ Zemp, M.; I.Roer; A.Kääb; M.Hoelzle; F.Paul; W. Haeberli (2008). (PDF) (Report). Archived from the original (PDF) on 25 March 2009. Retrieved 21 June 2009.
  125. ^ EPA, OA, US (July 2016). "Climate Change Indicators: Glaciers". US EPA. from the original on 29 September 2019. Retrieved 26 January 2018.
  126. ^ "Land ice – NASA Global Climate Change". from the original on 23 February 2017. Retrieved 10 December 2017.
  127. ^ Shaftel, Holly (ed.). "Climate Change: How do we know?". NASA Global Climate Change. Earth Science Communications Team at NASA's Jet Propulsion Laboratory. from the original on 18 December 2019. Retrieved 16 December 2017.
  128. ^ "GISS Surface Temperature Analysis (v4) / Annual Mean Temperature Change over Land and over Ocean". NASA GISS. from the original on 16 April 2020.
  129. ^ a b Harvey, Chelsea (1 November 2018). "The Oceans Are Heating Up Faster Than Expected". Scientific American. from the original on 3 March 2020. Data from .
  130. ^ "GISS Surface Temperature Analysis (v4) / Annual Mean Temperature Change for Hemispheres". NASA GISS. from the original on 16 April 2020.
  131. ^ a b Freedman, Andrew (9 April 2013). "In Warming, Northern Hemisphere is Outpacing the South". Climate Central. from the original on 31 October 2019.
  132. ^ a b "GISS Surface Temperature Analysis (v4) / Temperature Change for Three Latitude Bands". NASA GISS. from the original on 16 April 2020.
  133. ^ a b Hawkins, Ed (12 September 2019). "Atmospheric temperature trends". Climate Lab Book. from the original on 12 September 2019. (Higher-altitude cooling differences attributed to ozone depletion and greenhouse gas increases; spikes occurred with volcanic eruptions of 1982–83 (El Chichón) and 1991–92 (Pinatubo).)
  134. ^ a b Meduna, Veronika (17 September 2018). "The climate visualisations that leave no room for doubt or denial". The Spinoff. New Zealand. from the original on 17 May 2019.
  135. ^ "Climate at a Glance / Global Time Series". NCDC / NOAA. from the original on 23 February 2020.
  136. ^ a b Hawkins, Ed (10 March 2020). "From the familiar to the unknown". Climate Lab Book (professional blog). from the original on 23 April 2020. (; Hawkins credits Berkeley Earth for data.) "The emergence of observed temperature changes over both land and ocean is clearest in tropical regions, in contrast to the regions of largest change which are in the northern extra-tropics. As an illustration, northern America has warmed more than tropical America, but the changes in the tropics are more apparent and have more clearly emerged from the range of historical variability. The year-to-year variations in the higher latitudes have made it harder to distinguish the long-term changes."
  137. ^ a b Lenton, Timothy M.; Rockström, Johan; Gaffney, Owen; Rahmstorf, Stefan; Richardson, Katherine; Steffen, Will; Schellnhuber, Hans Joachim (27 November 2019). "Climate tipping points – too risky to bet against". Nature. 575 (7784): 592–595. Bibcode:2019Natur.575..592L. doi:10.1038/d41586-019-03595-0. hdl:10871/40141. PMID 31776487. Correction dated 9 April 2020

References

  • Cronin, Thomas N. (2010). Paleoclimates: understanding climate change past and present. New York: Columbia University Press. ISBN 978-0-231-14494-0.
  • IPCC (2007). Solomon, S.; Qin, D.; Manning, M.; Chen, Z.; et al. (eds.). Climate Change 2007: The Physical Science Basis (PDF). Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. ISBN 978-0-521-88009-1. (pb: 978-0-521-70596-7).
  • IPCC (2008). The Core Writing Team; Pachauri, R.K.; Reisinger, A.R. (eds.). Climate Change 2008: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Geneva, Switzerland: IPCC. ISBN 978-92-9169-122-7.[permanent dead link].
  • Burroughs, William James (2001). Climate Change : A multidisciplinary approach. Cambridge: Cambridge university press. ISBN 0521567718.
  • Burroughs, William James (2007). Climate Change : A multidisciplinary approach. Cambridge: Cambridge University Press. ISBN 978-0-511-37027-4.
  • Ruddiman, William F. (2008). Earth's climate : Past and Future. New York: W. H. Freeman and Company. ISBN 978-0716784906.
  • Rohli, Robert. V.; Vega, Anthony J. (2018). Climatology (4th ed.). Jones & Bartlett Learning. ISBN 978-1284126563.

External links

  • Global Climate Change from NASA (US)
  • Intergovernmental Panel on Climate Change (IPCC)
  • Climate Variability 30 May 2023 at the Wayback Machine – NASA Science
  • Climate Change and Variability, National Centers for Environmental Information 21 September 2021 at the Wayback Machine

climate, variability, change, human, induced, rise, earth, average, temperature, effects, climate, change, climate, variability, includes, variations, climate, that, last, longer, than, individual, weather, events, whereas, term, climate, change, only, refers,. For the human induced rise in Earth s average temperature and its effects see Climate change Climate variability includes all the variations in the climate that last longer than individual weather events whereas the term climate change only refers to those variations that persist for a longer period of time typically decades or more Climate change may refer to any time in Earth s history but the term is now commonly used to describe contemporary climate change often popularly referred to as global warming Since the Industrial Revolution the climate has increasingly been affected by human activities 1 The climate system receives nearly all of its energy from the sun and radiates energy to outer space The balance of incoming and outgoing energy and the passage of the energy through the climate system is Earth s energy budget When the incoming energy is greater than the outgoing energy Earth s energy budget is positive and the climate system is warming If more energy goes out the energy budget is negative and Earth experiences cooling The energy moving through Earth s climate system finds expression in weather varying on geographic scales and time Long term averages and variability of weather in a region constitute the region s climate Such changes can be the result of internal variability when natural processes inherent to the various parts of the climate system alter the distribution of energy Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation Climate variability can also result from external forcing when events outside of the climate system s components produce changes within the system Examples include changes in solar output and volcanism Climate variability has consequences for sea level changes plant life and mass extinctions it also affects human societies Contents 1 Terminology 2 Causes 2 1 Internal variability 2 1 1 Ocean atmosphere variability 2 1 2 Oscillations and cycles 2 1 3 Ocean current changes 2 1 4 Life 2 2 External climate forcing 2 2 1 Greenhouse gases 2 2 2 Orbital variations 2 2 3 Solar output 2 2 4 Volcanism 2 2 5 Plate tectonics 2 2 6 Other mechanisms 3 Evidence and measurement of climate changes 3 1 Direct measurements 3 2 Proxy measurements 3 3 Analysis and uncertainties 4 Impacts 4 1 Life 4 1 1 Vegetation 4 1 2 Wildlife 4 1 3 Humanity 4 2 Changes in the cryosphere 4 2 1 Glaciers and ice sheets 4 2 2 Sea level change 4 2 3 Sea ice 5 Climate history 5 1 Paleo eocene thermal maximum 5 2 The Cenozoic 5 2 1 The Holocene 5 3 Modern climate change and global warming 5 3 1 Variability between regions 6 See also 7 Notes 8 References 9 External linksTerminologyClimate variability is the term to describe variations in the mean state and other characteristics of climate such as chances or possibility of extreme weather etc on all spatial and temporal scales beyond that of individual weather events Some of the variability does not appear to be caused by known systems and occurs at seemingly random times Such variability is called random variability or noise On the other hand periodic variability occurs relatively regularly and in distinct modes of variability or climate patterns 2 The term climate change is often used to refer specifically to anthropogenic climate change Anthropogenic climate change is caused by human activity as opposed to changes in climate that may have resulted as part of Earth s natural processes 3 Global warming became the dominant popular term in 1988 but within scientific journals global warming refers to surface temperature increases while climate change includes global warming and everything else that increasing greenhouse gas levels affect 4 A related term climatic change was proposed by the World Meteorological Organization WMO in 1966 to encompass all forms of climatic variability on time scales longer than 10 years but regardless of cause During the 1970s the term climate change replaced climatic change to focus on anthropogenic causes as it became clear that human activities had a potential to drastically alter the climate 5 Climate change was incorporated in the title of the Intergovernmental Panel on Climate Change IPCC and the UN Framework Convention on Climate Change UNFCCC Climate change is now used as both a technical description of the process as well as a noun used to describe the problem 5 CausesSee also Attribution of recent climate change On the broadest scale the rate at which energy is received from the Sun and the rate at which it is lost to space determine the equilibrium temperature and climate of Earth This energy is distributed around the globe by winds ocean currents 6 7 and other mechanisms to affect the climates of different regions 8 Factors that can shape climate are called climate forcings or forcing mechanisms 9 These include processes such as variations in solar radiation variations in the Earth s orbit variations in the albedo or reflectivity of the continents atmosphere and oceans mountain building and continental drift and changes in greenhouse gas concentrations External forcing can be either anthropogenic e g increased emissions of greenhouse gases and dust or natural e g changes in solar output the Earth s orbit volcano eruptions 10 There are a variety of climate change feedbacks that can either amplify or diminish the initial forcing There are also key thresholds which when exceeded can produce rapid or irreversible change Some parts of the climate system such as the oceans and ice caps respond more slowly in reaction to climate forcings while others respond more quickly An example of fast change is the atmospheric cooling after a volcanic eruption when volcanic ash reflects sunlight Thermal expansion of ocean water after atmospheric warming is slow and can take thousands of years A combination is also possible e g sudden loss of albedo in the Arctic Ocean as sea ice melts followed by more gradual thermal expansion of the water Climate variability can also occur due to internal processes Internal unforced processes often involve changes in the distribution of energy in the ocean and atmosphere for instance changes in the thermohaline circulation Internal variability nbsp There is seasonal variability in how new high temperature records have outpaced new low temperature records 11 Climatic changes due to internal variability sometimes occur in cycles or oscillations For other types of natural climatic change we cannot predict when it happens the change is called random or stochastic 12 From a climate perspective the weather can be considered random 13 If there are little clouds in a particular year there is an energy imbalance and extra heat can be absorbed by the oceans Due to climate inertia this signal can be stored in the ocean and be expressed as variability on longer time scales than the original weather disturbances 14 If the weather disturbances are completely random occurring as white noise the inertia of glaciers or oceans can transform this into climate changes where longer duration oscillations are also larger oscillations a phenomenon called red noise 15 Many climate changes have a random aspect and a cyclical aspect This behavior is dubbed stochastic resonance 15 Half of the 2021 Nobel prize on physics was awarded for this work to Klaus Hasselmann jointly with Syukuro Manabe for related work on climate modelling While Giorgio Parisi who with collaborators introduced 16 the concept of stochastic resonance was awarded the other half but mainly for work on theoretical physics Ocean atmosphere variability The ocean and atmosphere can work together to spontaneously generate internal climate variability that can persist for years to decades at a time 17 18 These variations can affect global average surface temperature by redistributing heat between the deep ocean and the atmosphere 19 20 and or by altering the cloud water vapor sea ice distribution which can affect the total energy budget of the Earth 21 22 Oscillations and cycles nbsp Colored bars show how El Nino years red regional warming and La Nina years blue regional cooling relate to overall global warming The El Nino Southern Oscillation has been linked to variability in longer term global average temperature increase A climate oscillation or climate cycle is any recurring cyclical oscillation within global or regional climate They are quasiperiodic not perfectly periodic so a Fourier analysis of the data does not have sharp peaks in the spectrum Many oscillations on different time scales have been found or hypothesized 23 the El Nino Southern Oscillation ENSO A large scale pattern of warmer El Nino and colder La Nina tropical sea surface temperatures in the Pacific Ocean with worldwide effects It is a self sustaining oscillation whose mechanisms are well studied 24 ENSO is the most prominent known source of inter annual variability in weather and climate around the world The cycle occurs every two to seven years with El Nino lasting nine months to two years within the longer term cycle 25 The cold tongue of the equatorial Pacific Ocean is not warming as fast as the rest of the ocean due to increased upwelling of cold waters off the west coast of South America 26 27 the Madden Julian oscillation MJO An eastward moving pattern of increased rainfall over the tropics with a period of 30 to 60 days observed mainly over the Indian and Pacific Oceans 28 the North Atlantic oscillation NAO Indices of the NAO are based on the difference of normalized sea level pressure SLP between Ponta Delgada Azores and Stykkisholmur Reykjavik Iceland Positive values of the index indicate stronger than average westerlies over the middle latitudes 29 the Quasi biennial oscillation a well understood oscillation in wind patterns in the stratosphere around the equator Over a period of 28 months the dominant wind changes from easterly to westerly and back 30 Pacific Centennial Oscillation a climate oscillation predicted by some climate models the Pacific decadal oscillation The dominant pattern of sea surface variability in the North Pacific on a decadal scale During a warm or positive phase the west Pacific becomes cool and part of the eastern ocean warms during a cool or negative phase the opposite pattern occurs It is thought not as a single phenomenon but instead a combination of different physical processes 31 the Interdecadal Pacific oscillation IPO Basin wide variability in the Pacific Ocean with a period between 20 and 30 years 32 the Atlantic multidecadal oscillation A pattern of variability in the North Atlantic of about 55 to 70 years with effects on rainfall droughts and hurricane frequency and intensity 33 North African climate cycles climate variation driven by the North African Monsoon with a period of tens of thousands of years 34 the Arctic oscillation AO and Antarctic oscillation AAO The annular modes are naturally occurring hemispheric wide patterns of climate variability On timescales of weeks to months they explain 20 30 of the variability in their respective hemispheres The Northern Annular Mode or Arctic oscillation AO in the Northern Hemisphere and the Southern Annular Mode or Antarctic oscillation AAO in the southern hemisphere The annular modes have a strong influence on the temperature and precipitation of mid to high latitude land masses such as Europe and Australia by altering the average paths of storms The NAO can be considered a regional index of the AO NAM 35 They are defined as the first EOF of sea level pressure or geopotential height from 20 N to 90 N NAM or 20 S to 90 S SAM Dansgaard Oeschger cycles occurring on roughly 1 500 year cycles during the Last Glacial MaximumOcean current changes See also Thermohaline circulation nbsp A schematic of modern thermohaline circulation Tens of millions of years ago continental plate movement formed a land free gap around Antarctica allowing the formation of the ACC which keeps warm waters away from Antarctica The oceanic aspects of climate variability can generate variability on centennial timescales due to the ocean having hundreds of times more mass than in the atmosphere and thus very high thermal inertia For example alterations to ocean processes such as thermohaline circulation play a key role in redistributing heat in the world s oceans Ocean currents transport a lot of energy from the warm tropical regions to the colder polar regions Changes occurring around the last ice age in technical terms the last glacial show that the circulation is the North Atlantic can change suddenly and substantially leading to global climate changes even though the total amount of energy coming into the climate system didn t change much These large changes may have come from so called Heinrich events where internal instability of ice sheets caused huge ice bergs to be released into the ocean When the ice sheet melts the resulting water is very low in salt and cold driving changes in circulation 36 Life Life affects climate through its role in the carbon and water cycles and through such mechanisms as albedo evapotranspiration cloud formation and weathering 37 38 39 Examples of how life may have affected past climate include glaciation 2 3 billion years ago triggered by the evolution of oxygenic photosynthesis which depleted the atmosphere of the greenhouse gas carbon dioxide and introduced free oxygen 40 41 another glaciation 300 million years ago ushered in by long term burial of decomposition resistant detritus of vascular land plants creating a carbon sink and forming coal 42 43 termination of the Paleocene Eocene Thermal Maximum 55 million years ago by flourishing marine phytoplankton 44 45 reversal of global warming 49 million years ago by 800 000 years of arctic azolla blooms 46 47 global cooling over the past 40 million years driven by the expansion of grass grazer ecosystems 48 49 External climate forcing Greenhouse gases Main article Greenhouse gas nbsp CO2 concentrations over the last 800 000 years as measured from ice cores blue green and directly black Whereas greenhouse gases released by the biosphere is often seen as a feedback or internal climate process greenhouse gases emitted from volcanoes are typically classified as external by climatologists 50 Greenhouse gases such as CO2 methane and nitrous oxide heat the climate system by trapping infrared light Volcanoes are also part of the extended carbon cycle Over very long geological time periods they release carbon dioxide from the Earth s crust and mantle counteracting the uptake by sedimentary rocks and other geological carbon dioxide sinks Since the industrial revolution humanity has been adding to greenhouse gases by emitting CO2 from fossil fuel combustion changing land use through deforestation and has further altered the climate with aerosols particulate matter in the atmosphere 51 release of trace gases e g nitrogen oxides carbon monoxide or methane 52 Other factors including land use ozone depletion animal husbandry ruminant animals such as cattle produce methane 53 and deforestation also play a role 54 The US Geological Survey estimates are that volcanic emissions are at a much lower level than the effects of current human activities which generate 100 300 times the amount of carbon dioxide emitted by volcanoes 55 The annual amount put out by human activities may be greater than the amount released by supereruptions the most recent of which was the Toba eruption in Indonesia 74 000 years ago 56 Orbital variations nbsp Milankovitch cycles from 800 000 years ago in the past to 800 000 years in the future Slight variations in Earth s motion lead to changes in the seasonal distribution of sunlight reaching the Earth s surface and how it is distributed across the globe There is very little change to the area averaged annually averaged sunshine but there can be strong changes in the geographical and seasonal distribution The three types of kinematic change are variations in Earth s eccentricity changes in the tilt angle of Earth s axis of rotation and precession of Earth s axis Combined these produce Milankovitch cycles which affect climate and are notable for their correlation to glacial and interglacial periods 57 their correlation with the advance and retreat of the Sahara 57 and for their appearance in the stratigraphic record 58 59 During the glacial cycles there was a high correlation between CO2 concentrations and temperatures Early studies indicated that CO2 concentrations lagged temperatures but it has become clear that this isn t always the case 60 When ocean temperatures increase the solubility of CO2 decreases so that it is released from the ocean The exchange of CO2 between the air and the ocean can also be impacted by further aspects of climatic change 61 These and other self reinforcing processes allow small changes in Earth s motion to have a large effect on climate 60 Solar output nbsp Variations in solar activity during the last several centuries based on observations of sunspots and beryllium isotopes The period of extraordinarily few sunspots in the late 17th century was the Maunder minimum The Sun is the predominant source of energy input to the Earth s climate system Other sources include geothermal energy from the Earth s core tidal energy from the Moon and heat from the decay of radioactive compounds Both long term variations in solar intensity are known to affect global climate 62 Solar output varies on shorter time scales including the 11 year solar cycle 63 and longer term modulations 64 Correlation between sunspots and climate and tenuous at best 62 Three to four billion years ago the Sun emitted only 75 as much power as it does today 65 If the atmospheric composition had been the same as today liquid water should not have existed on the Earth s surface However there is evidence for the presence of water on the early Earth in the Hadean 66 67 and Archean 68 66 eons leading to what is known as the faint young Sun paradox 69 Hypothesized solutions to this paradox include a vastly different atmosphere with much higher concentrations of greenhouse gases than currently exist 70 Over the following approximately 4 billion years the energy output of the Sun increased Over the next five billion years the Sun s ultimate death as it becomes a red giant and then a white dwarf will have large effects on climate with the red giant phase possibly ending any life on Earth that survives until that time 71 Volcanism nbsp In atmospheric temperature from 1979 to 2010 determined by MSU NASA satellites effects appear from aerosols released by major volcanic eruptions El Chichon and Pinatubo El Nino is a separate event from ocean variability The volcanic eruptions considered to be large enough to affect the Earth s climate on a scale of more than 1 year are the ones that inject over 100 000 tons of SO2 into the stratosphere 72 This is due to the optical properties of SO2 and sulfate aerosols which strongly absorb or scatter solar radiation creating a global layer of sulfuric acid haze 73 On average such eruptions occur several times per century and cause cooling by partially blocking the transmission of solar radiation to the Earth s surface for a period of several years Although volcanoes are technically part of the lithosphere which itself is part of the climate system the IPCC explicitly defines volcanism as an external forcing agent 74 Notable eruptions in the historical records are the 1991 eruption of Mount Pinatubo which lowered global temperatures by about 0 5 C 0 9 F for up to three years 75 76 and the 1815 eruption of Mount Tambora causing the Year Without a Summer 77 At a larger scale a few times every 50 million to 100 million years the eruption of large igneous provinces brings large quantities of igneous rock from the mantle and lithosphere to the Earth s surface Carbon dioxide in the rock is then released into the atmosphere 78 79 Small eruptions with injections of less than 0 1 Mt of sulfur dioxide into the stratosphere affect the atmosphere only subtly as temperature changes are comparable with natural variability However because smaller eruptions occur at a much higher frequency they too significantly affect Earth s atmosphere 72 80 Plate tectonics Main article Plate tectonics Over the course of millions of years the motion of tectonic plates reconfigures global land and ocean areas and generates topography This can affect both global and local patterns of climate and atmosphere ocean circulation 81 The position of the continents determines the geometry of the oceans and therefore influences patterns of ocean circulation The locations of the seas are important in controlling the transfer of heat and moisture across the globe and therefore in determining global climate A recent example of tectonic control on ocean circulation is the formation of the Isthmus of Panama about 5 million years ago which shut off direct mixing between the Atlantic and Pacific Oceans This strongly affected the ocean dynamics of what is now the Gulf Stream and may have led to Northern Hemisphere ice cover 82 83 During the Carboniferous period about 300 to 360 million years ago plate tectonics may have triggered large scale storage of carbon and increased glaciation 84 Geologic evidence points to a megamonsoonal circulation pattern during the time of the supercontinent Pangaea and climate modeling suggests that the existence of the supercontinent was conducive to the establishment of monsoons 85 The size of continents is also important Because of the stabilizing effect of the oceans on temperature yearly temperature variations are generally lower in coastal areas than they are inland A larger supercontinent will therefore have more area in which climate is strongly seasonal than will several smaller continents or islands Other mechanisms It has been postulated that ionized particles known as cosmic rays could impact cloud cover and thereby the climate As the sun shields the Earth from these particles changes in solar activity were hypothesized to influence climate indirectly as well To test the hypothesis CERN designed the CLOUD experiment which showed the effect of cosmic rays is too weak to influence climate noticeably 86 87 Evidence exists that the Chicxulub asteroid impact some 66 million years ago had severely affected the Earth s climate Large quantities of sulfate aerosols were kicked up into the atmosphere decreasing global temperatures by up to 26 C and producing sub freezing temperatures for a period of 3 16 years The recovery time for this event took more than 30 years 88 The large scale use of nuclear weapons has also been investigated for its impact on the climate The hypothesis is that soot released by large scale fires blocks a significant fraction of sunlight for as much as a year leading to a sharp drop in temperatures for a few years This possible event is described as nuclear winter 89 Humans use of land impact how much sunlight the surface reflects and the concentration of dust Cloud formation is not only influenced by how much water is in the air and the temperature but also by the amount of aerosols in the air such as dust 90 Globally more dust is available if there are many regions with dry soils little vegetation and strong winds 91 Evidence and measurement of climate changesPaleoclimatology is the study of changes in climate through the entire history of Earth It uses a variety of proxy methods from the Earth and life sciences to obtain data preserved within things such as rocks sediments ice sheets tree rings corals shells and microfossils It then uses the records to determine the past states of the Earth s various climate regions and its atmospheric system Direct measurements give a more complete overview of climate variability Direct measurements Climate changes that occurred after the widespread deployment of measuring devices can be observed directly Reasonably complete global records of surface temperature are available beginning from the mid late 19th century Further observations are derived indirectly from historical documents Satellite cloud and precipitation data has been available since the 1970s 92 Historical climatology is the study of historical changes in climate and their effect on human history and development The primary sources include written records such as sagas chronicles maps and local history literature as well as pictorial representations such as paintings drawings and even rock art Climate variability in the recent past may be derived from changes in settlement and agricultural patterns 93 Archaeological evidence oral history and historical documents can offer insights into past changes in the climate Changes in climate have been linked to the rise 94 and the collapse of various civilizations 93 Proxy measurements nbsp Variations in CO2 temperature and dust from the Vostok ice core over the last 450 000 years Various archives of past climate are present in rocks trees and fossils From these archives indirect measures of climate so called proxies can be derived Quantification of climatological variation of precipitation in prior centuries and epochs is less complete but approximated using proxies such as marine sediments ice cores cave stalagmites and tree rings 95 Stress too little precipitation or unsuitable temperatures can alter the growth rate of trees which allows scientists to infer climate trends by analyzing the growth rate of tree rings This branch of science studying this called dendroclimatology 96 Glaciers leave behind moraines that contain a wealth of material including organic matter quartz and potassium that may be dated recording the periods in which a glacier advanced and retreated Analysis of ice in cores drilled from an ice sheet such as the Antarctic ice sheet can be used to show a link between temperature and global sea level variations The air trapped in bubbles in the ice can also reveal the CO2 variations of the atmosphere from the distant past well before modern environmental influences The study of these ice cores has been a significant indicator of the changes in CO2 over many millennia and continues to provide valuable information about the differences between ancient and modern atmospheric conditions The 18O 16O ratio in calcite and ice core samples used to deduce ocean temperature in the distant past is an example of a temperature proxy method The remnants of plants and specifically pollen are also used to study climatic change Plant distributions vary under different climate conditions Different groups of plants have pollen with distinctive shapes and surface textures and since the outer surface of pollen is composed of a very resilient material they resist decay Changes in the type of pollen found in different layers of sediment indicate changes in plant communities These changes are often a sign of a changing climate 97 98 As an example pollen studies have been used to track changing vegetation patterns throughout the Quaternary glaciations 99 and especially since the last glacial maximum 100 Remains of beetles are common in freshwater and land sediments Different species of beetles tend to be found under different climatic conditions Given the extensive lineage of beetles whose genetic makeup has not altered significantly over the millennia knowledge of the present climatic range of the different species and the age of the sediments in which remains are found past climatic conditions may be inferred 101 Analysis and uncertainties One difficulty in detecting climate cycles is that the Earth s climate has been changing in non cyclic ways over most paleoclimatological timescales Currently we are in a period of anthropogenic global warming In a larger timeframe the Earth is emerging from the latest ice age cooling from the Holocene climatic optimum and warming from the Little Ice Age which means that climate has been constantly changing over the last 15 000 years or so During warm periods temperature fluctuations are often of a lesser amplitude The Pleistocene period dominated by repeated glaciations developed out of more stable conditions in the Miocene and Pliocene climate Holocene climate has been relatively stable All of these changes complicate the task of looking for cyclical behavior in the climate Positive feedback negative feedback and ecological inertia from the land ocean atmosphere system often attenuate or reverse smaller effects whether from orbital forcings solar variations or changes in concentrations of greenhouse gases Certain feedbacks involving processes such as clouds are also uncertain for contrails natural cirrus clouds oceanic dimethyl sulfide and a land based equivalent competing theories exist concerning effects on climatic temperatures for example contrasting the Iris hypothesis and CLAW hypothesis ImpactsLife nbsp Top Arid ice age climateMiddle Atlantic Period warm and wetBottom Potential vegetation in climate now if not for human effects like agriculture 102 Vegetation A change in the type distribution and coverage of vegetation may occur given a change in the climate Some changes in climate may result in increased precipitation and warmth resulting in improved plant growth and the subsequent sequestration of airborne CO2 The effects are expected to affect the rate of many natural cycles like plant litter decomposition rates 103 A gradual increase in warmth in a region will lead to earlier flowering and fruiting times driving a change in the timing of life cycles of dependent organisms Conversely cold will cause plant bio cycles to lag 104 Larger faster or more radical changes however may result in vegetation stress rapid plant loss and desertification in certain circumstances 105 106 An example of this occurred during the Carboniferous Rainforest Collapse CRC an extinction event 300 million years ago At this time vast rainforests covered the equatorial region of Europe and America Climate change devastated these tropical rainforests abruptly fragmenting the habitat into isolated islands and causing the extinction of many plant and animal species 105 Wildlife One of the most important ways animals can deal with climatic change is migration to warmer or colder regions 107 On a longer timescale evolution makes ecosystems including animals better adapted to a new climate 108 Rapid or large climate change can cause mass extinctions when creatures are stretched too far to be able to adapt 109 Humanity Collapses of past civilizations such as the Maya may be related to cycles of precipitation especially drought that in this example also correlates to the Western Hemisphere Warm Pool Around 70 000 years ago the Toba supervolcano eruption created an especially cold period during the ice age leading to a possible genetic bottleneck in human populations Changes in the cryosphere Glaciers and ice sheets Glaciers are considered among the most sensitive indicators of a changing climate 110 Their size is determined by a mass balance between snow input and melt output As temperatures increase glaciers retreat unless snow precipitation increases to make up for the additional melt Glaciers grow and shrink due both to natural variability and external forcings Variability in temperature precipitation and hydrology can strongly determine the evolution of a glacier in a particular season The most significant climate processes since the middle to late Pliocene approximately 3 million years ago are the glacial and interglacial cycles The present interglacial period the Holocene has lasted about 11 700 years 111 Shaped by orbital variations responses such as the rise and fall of continental ice sheets and significant sea level changes helped create the climate Other changes including Heinrich events Dansgaard Oeschger events and the Younger Dryas however illustrate how glacial variations may also influence climate without the orbital forcing Sea level change During the Last Glacial Maximum some 25 000 years ago sea levels were roughly 130 m lower than today The deglaciation afterwards was characterized by rapid sea level change 112 In the early Pliocene global temperatures were 1 2 C warmer than the present temperature yet sea level was 15 25 meters higher than today 113 Sea ice Sea ice plays an important role in Earth s climate as it affects the total amount of sunlight that is reflected away from the Earth 114 In the past the Earth s oceans have been almost entirely covered by sea ice on a number of occasions when the Earth was in a so called Snowball Earth state 115 and completely ice free in periods of warm climate 116 When there is a lot of sea ice present globally especially in the tropics and subtropics the climate is more sensitive to forcings as the ice albedo feedback is very strong 117 Climate historySee also List of periods and events in climate history and Paleoclimatology Various climate forcings are typically in flux throughout geologic time and some processes of the Earth s temperature may be self regulating For example during the Snowball Earth period large glacial ice sheets spanned to Earth s equator covering nearly its entire surface and very high albedo created extremely low temperatures while the accumulation of snow and ice likely removed carbon dioxide through atmospheric deposition However the absence of plant cover to absorb atmospheric CO2 emitted by volcanoes meant that the greenhouse gas could accumulate in the atmosphere There was also an absence of exposed silicate rocks which use CO2 when they undergo weathering This created a warming that later melted the ice and brought Earth s temperature back up Paleo eocene thermal maximum nbsp Climate changes over the past 65 million years using proxy data including Oxygen 18 ratios from foraminifera The Paleocene Eocene Thermal Maximum PETM was a time period with more than 5 8 C global average temperature rise across the event 118 This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs 119 During the event large amounts of methane was released a potent greenhouse gas 120 The PETM represents a case study for modern climate change as in the greenhouse gases were released in a geologically relatively short amount of time 118 During the PETM a mass extinction of organisms in the deep ocean took place 121 The Cenozoic Throughout the Cenozoic multiple climate forcings led to warming and cooling of the atmosphere which led to the early formation of the Antarctic ice sheet subsequent melting and its later reglaciation The temperature changes occurred somewhat suddenly at carbon dioxide concentrations of about 600 760 ppm and temperatures approximately 4 C warmer than today During the Pleistocene cycles of glaciations and interglacials occurred on cycles of roughly 100 000 years but may stay longer within an interglacial when orbital eccentricity approaches zero as during the current interglacial Previous interglacials such as the Eemian phase created temperatures higher than today higher sea levels and some partial melting of the West Antarctic ice sheet Climatological temperatures substantially affect cloud cover and precipitation At lower temperatures air can hold less water vapour which can lead to decreased precipitation 122 During the Last Glacial Maximum of 18 000 years ago thermal driven evaporation from the oceans onto continental landmasses was low causing large areas of extreme desert including polar deserts cold but with low rates of cloud cover and precipitation 102 In contrast the world s climate was cloudier and wetter than today near the start of the warm Atlantic Period of 8000 years ago 102 The Holocene nbsp Temperature change over the past 12 000 years from various sources The thick black curve is an average The Holocene is characterized by a long term cooling starting after the Holocene Optimum when temperatures were probably only just below current temperatures second decade of the 21st century 123 and a strong African Monsoon created grassland conditions in the Sahara during the Neolithic Subpluvial Since that time several cooling events have occurred including the Piora Oscillation the Middle Bronze Age Cold Epoch the Iron Age Cold Epoch the Little Ice Age the phase of cooling c 1940 1970 which led to global cooling hypothesisIn contrast several warm periods have also taken place and they include but are not limited to a warm period during the apex of the Minoan civilization the Roman Warm Period the Medieval Warm Period Modern warming during the 20th centuryCertain effects have occurred during these cycles For example during the Medieval Warm Period the American Midwest was in drought including the Sand Hills of Nebraska which were active sand dunes The black death plague of Yersinia pestis also occurred during Medieval temperature fluctuations and may be related to changing climates Solar activity may have contributed to part of the modern warming that peaked in the 1930s However solar cycles fail to account for warming observed since the 1980s to the present day citation needed Events such as the opening of the Northwest Passage and recent record low ice minima of the modern Arctic shrinkage have not taken place for at least several centuries as early explorers were all unable to make an Arctic crossing even in summer Shifts in biomes and habitat ranges are also unprecedented occurring at rates that do not coincide with known climate oscillations citation needed Modern climate change and global warming Main article Climate change As a consequence of humans emitting greenhouse gases global surface temperatures have started rising Global warming is an aspect of modern climate change a term that also includes the observed changes in precipitation storm tracks and cloudiness As a consequence glaciers worldwide have been found to be shrinking significantly 124 125 Land ice sheets in both Antarctica and Greenland have been losing mass since 2002 and have seen an acceleration of ice mass loss since 2009 126 Global sea levels have been rising as a consequence of thermal expansion and ice melt The decline in Arctic sea ice both in extent and thickness over the last several decades is further evidence for rapid climate change 127 Variability between regions Examples of regional climate variability nbsp Land ocean Surface air temperatures over land masses have been increasing faster than those over the ocean 128 the ocean absorbing about 90 of excess heat 129 nbsp Hemispheres The Hemispheres average temperature changes 130 have diverged because of the North s greater percentage of landmass and due to global ocean currents 131 nbsp Latitude bands Three latitude bands that respectively cover 30 40 and 30 percent of the global surface area show mutually distinct temperature growth patterns in recent decades 132 nbsp Altitude A warming stripes graphic blues denote cool reds denote warm shows how the greenhouse effect traps heat in the lower atmosphere so that the upper atmosphere receiving less reflected energy cools Volcanos cause upper atmosphere temperature spikes 133 nbsp Global versus regional For geographical and statistical reasons larger year to year variations are expected 134 for localized geographic regions e g the Caribbean than for global averages 135 nbsp Relative deviation Though northern America has warmed more than its tropics the tropics have more clearly departed from normal historical variability colored bands 1s 2s standard deviations 136 source source source source source source source source Global warming has varied substantially by latitude with the northernmost latitude zones experiencing the largest temperature increases In addition to global climate variability and global climate change over time numerous climatic variations occur contemporaneously across different physical regions The oceans absorption of about 90 of excess heat has helped to cause land surface temperatures to grow more rapidly than sea surface temperatures 129 The Northern Hemisphere having a larger landmass to ocean ratio than the Southern Hemisphere shows greater average temperature increases 131 Variations across different latitude bands also reflect this divergence in average temperature increase with the temperature increase of northern extratropics exceeding that of the tropics which in turn exceeds that of the southern extratropics 132 Upper regions of the atmosphere have been cooling contemporaneously with a warming in the lower atmosphere confirming the action of the greenhouse effect and ozone depletion 133 Observed regional climatic variations confirm predictions concerning ongoing changes for example by contrasting smoother year to year global variations with more volatile year to year variations in localized regions 134 Conversely comparing different regions warming patterns to their respective historical variabilities allows the raw magnitudes of temperature changes to be placed in the perspective of what is normal variability for each region 136 Regional variability observations permit study of regionalized climate tipping points such as rainforest loss ice sheet and sea ice melt and permafrost thawing 137 Such distinctions underlie research into a possible global cascade of tipping points 137 See also nbsp Environment portal nbsp Global warming portal nbsp Energy portalClimatological normal AnthropoceneNotes America s Climate Choices Panel on Advancing the Science of Climate Change National Research Council 2010 Advancing the Science of Climate Change Washington D C The National Academies Press ISBN 978 0 309 14588 6 Archived from the original on 29 May 2014 p1 there is a strong credible body of evidence based on multiple lines of research documenting that climate is changing and that these changes are in large part caused by human activities While much remains to be learned the core phenomenon scientific questions and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations pp 21 22 Some scientific conclusions or theories have been so thoroughly examined and tested and supported by so many independent observations and results that their likelihood of subsequently being found to be wrong is vanishingly small Such conclusions and theories are then regarded as settled facts This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities Rohli amp Vega 2018 p 274 The United Nations Framework Convention on Climate Change 21 March 1994 Archived from the original on 20 September 2022 Retrieved 9 October 2018 Climate change means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods What s in a Name Global Warming vs Climate Change NASA 5 December 2008 Archived from the original on 9 August 2010 Retrieved 23 July 2011 a b Hulme Mike 2016 Concept of Climate Change in The International Encyclopedia of Geography The International Encyclopedia of Geography Wiley Blackwell Association of American Geographers AAG 1 Archived from the original on 29 September 2022 Retrieved 16 May 2016 Hsiung Jane November 1985 Estimates of Global Oceanic Meridional Heat Transport Journal of Physical Oceanography 15 11 1405 13 Bibcode 1985JPO 15 1405H doi 10 1175 1520 0485 1985 015 lt 1405 EOGOMH gt 2 0 CO 2 Vallis Geoffrey K Farneti Riccardo October 2009 Meridional energy transport in the coupled atmosphere ocean system scaling and numerical experiments Quarterly Journal of the Royal Meteorological Society 135 644 1643 60 Bibcode 2009QJRMS 135 1643V doi 10 1002 qj 498 S2CID 122384001 Trenberth Kevin E et al 2009 Earth s Global Energy Budget Bulletin of the American Meteorological Society 90 3 311 23 Bibcode 2009BAMS 90 311T doi 10 1175 2008BAMS2634 1 Smith Ralph C 2013 Uncertainty Quantification Theory Implementation and Applications Computational Science and Engineering Vol 12 SIAM p 23 ISBN 978 1611973228 Cronin 2010 pp 17 18 Mean Monthly Temperature Records Across the Globe Timeseries of Global Land and Ocean Areas at Record Levels for October from 1951 2023 NCEI NOAA gov National Centers for Environmental Information NCEI of the National Oceanic and Atmospheric Administration NOAA November 2023 Archived from the original on 16 November 2023 change 202310 in URL to see years other than 2023 and months other than 10 October Ruddiman 2008 pp 261 62 Hasselmann K 1976 Stochastic climate models Part I Theory Tellus 28 6 473 85 Bibcode 1976Tell 28 473H doi 10 1111 j 2153 3490 1976 tb00696 x ISSN 2153 3490 Liu Zhengyu 14 October 2011 Dynamics of Interdecadal Climate Variability A Historical Perspective Journal of Climate 25 6 1963 95 doi 10 1175 2011JCLI3980 1 ISSN 0894 8755 S2CID 53953041 a b Ruddiman 2008 p 262 Benzi R Parisi G Sutera A Vulpiani A 1982 Stochastic resonance in climatic change Tellus 34 1 10 6 Bibcode 1982Tell 34 10B doi 10 1111 j 2153 3490 1982 tb01787 x Brown Patrick T Li Wenhong Cordero Eugene C Mauget Steven A 21 April 2015 Comparing the model simulated global warming signal to observations using empirical estimates of unforced noise Scientific Reports 5 9957 Bibcode 2015NatSR 5E9957B doi 10 1038 srep09957 ISSN 2045 2322 PMC 4404682 PMID 25898351 Hasselmann K 1 December 1976 Stochastic climate models Part I Theory Tellus 28 6 473 85 Bibcode 1976Tell 28 473H doi 10 1111 j 2153 3490 1976 tb00696 x ISSN 2153 3490 Meehl Gerald A Hu Aixue Arblaster Julie M Fasullo John Trenberth Kevin E 8 April 2013 Externally Forced and Internally Generated Decadal Climate Variability Associated with the Interdecadal Pacific Oscillation Journal of Climate 26 18 7298 310 Bibcode 2013JCli 26 7298M doi 10 1175 JCLI D 12 00548 1 ISSN 0894 8755 OSTI 1565088 S2CID 16183172 Archived from the original on 11 March 2023 Retrieved 5 June 2020 England Matthew H McGregor Shayne Spence Paul Meehl Gerald A Timmermann Axel Cai Wenju Gupta Alex Sen McPhaden Michael J Purich Ariaan 1 March 2014 Recent intensification of wind driven circulation in the Pacific and the ongoing warming hiatus Nature Climate Change 4 3 222 27 Bibcode 2014NatCC 4 222E doi 10 1038 nclimate2106 ISSN 1758 678X Brown Patrick T Li Wenhong Li Laifang Ming Yi 28 July 2014 Top of atmosphere radiative contribution to unforced decadal global temperature variability in climate models Geophysical Research Letters 41 14 2014GL060625 Bibcode 2014GeoRL 41 5175B doi 10 1002 2014GL060625 hdl 10161 9167 ISSN 1944 8007 S2CID 16933795 Palmer M D McNeall D J 1 January 2014 Internal variability of Earth s energy budget simulated by CMIP5 climate models Environmental Research Letters 9 3 034016 Bibcode 2014ERL 9c4016P doi 10 1088 1748 9326 9 3 034016 ISSN 1748 9326 El Nino amp Other Oscillations Woods Hole Oceanographic Institution Archived from the original on 6 April 2019 Retrieved 6 April 2019 Wang Chunzai 2018 A review of ENSO theories National Science Review 5 6 813 825 doi 10 1093 nsr nwy104 ISSN 2095 5138 Climate Prediction Center 19 December 2005 ENSO FAQ How often do El Nino and La Nina typically occur National Centers for Environmental Prediction Archived from the original on 27 August 2009 Retrieved 26 July 2009 Kevin Krajick Part of the Pacific Ocean Is Not Warming as Expected Why Columbia University Lamont Doherty Earth Observatory Archived from the original on 5 March 2023 Retrieved 2 November 2022 Aristos Georgiou 26 June 2019 Mystery Stretch of the Pacific Ocean Is Not Warming Like the Rest of the World s Waters Newsweek Archived from the original on 25 February 2023 Retrieved 2 November 2022 What is the MJO and why do we care NOAA Climate gov Archived from the original on 15 March 2023 Retrieved 6 April 2019 National Center for Atmospheric Research Climate Analysis Section Archived 22 June 2006 at the Wayback Machine Retrieved on 7 June 2007 Baldwin M P Gray L J Dunkerton T J Hamilton K Haynes P H Randel W J Holton J R Alexander M J Hirota I 2001 The quasi biennial oscillation Reviews of Geophysics 39 2 179 229 Bibcode 2001RvGeo 39 179B doi 10 1029 1999RG000073 S2CID 16727059 Newman Matthew Alexander Michael A Ault Toby R Cobb Kim M Deser Clara Di Lorenzo Emanuele Mantua Nathan J Miller Arthur J Minobe Shoshiro 2016 The Pacific Decadal Oscillation Revisited Journal of Climate 29 12 4399 4427 Bibcode 2016JCli 29 4399N doi 10 1175 JCLI D 15 0508 1 ISSN 0894 8755 S2CID 4824093 Interdecadal Pacific Oscillation NIWA 19 January 2016 Archived from the original on 17 March 2023 Retrieved 6 April 2019 Kuijpers Antoon Bo Holm Jacobsen Seidenkrantz Marit Solveig Knudsen Mads Faurschou 2011 Tracking the Atlantic Multidecadal Oscillation through the last 8 000 years Nature Communications 2 178 Bibcode 2011NatCo 2 178K doi 10 1038 ncomms1186 ISSN 2041 1723 PMC 3105344 PMID 21285956 Skonieczny C 2 January 2019 Monsoon driven Saharan dust variability over the past 240 000 years Science Advances 5 1 eaav1887 Bibcode 2019SciA 5 1887S doi 10 1126 sciadv aav1887 PMC 6314818 PMID 30613782 Thompson David Annular Modes Introduction Archived from the original on 18 March 2023 Retrieved 11 February 2020 Burroughs 2001 pp 207 08 Spracklen D V Bonn B Carslaw K S 2008 Boreal forests aerosols and the impacts on clouds and climate Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences 366 1885 4613 26 Bibcode 2008RSPTA 366 4613S doi 10 1098 rsta 2008 0201 PMID 18826917 S2CID 206156442 Christner B C Morris C E Foreman C M Cai R Sands D C 2008 Ubiquity of Biological Ice Nucleators in Snowfall PDF Science 319 5867 1214 Bibcode 2008Sci 319 1214C doi 10 1126 science 1149757 PMID 18309078 S2CID 39398426 Archived PDF from the original on 5 March 2020 Schwartzman David W Volk Tyler 1989 Biotic enhancement of weathering and the habitability of Earth Nature 340 6233 457 60 Bibcode 1989Natur 340 457S doi 10 1038 340457a0 S2CID 4314648 Kopp R E Kirschvink J L Hilburn I A Nash C Z 2005 The Paleoproterozoic snowball Earth A climate disaster triggered by the evolution of oxygenic photosynthesis Proceedings of the National Academy of Sciences 102 32 11131 36 Bibcode 2005PNAS 10211131K doi 10 1073 pnas 0504878102 PMC 1183582 PMID 16061801 Kasting J F Siefert JL 2002 Life and the Evolution of Earth s Atmosphere Science 296 5570 1066 68 Bibcode 2002Sci 296 1066K doi 10 1126 science 1071184 PMID 12004117 S2CID 37190778 Mora C I Driese S G Colarusso L A 1996 Middle to Late Paleozoic Atmospheric CO2 Levels from Soil Carbonate and Organic Matter Science 271 5252 1105 07 Bibcode 1996Sci 271 1105M doi 10 1126 science 271 5252 1105 S2CID 128479221 Berner R A 1999 Atmospheric oxygen over Phanerozoic time Proceedings of the National Academy of Sciences 96 20 10955 57 Bibcode 1999PNAS 9610955B doi 10 1073 pnas 96 20 10955 PMC 34224 PMID 10500106 Bains Santo Norris Richard D Corfield Richard M Faul Kristina L 2000 Termination of global warmth at the Palaeocene Eocene boundary through productivity feedback Nature 407 6801 171 74 Bibcode 2000Natur 407 171B doi 10 1038 35025035 PMID 11001051 S2CID 4419536 Zachos J C Dickens G R 2000 An assessment of the biogeochemical feedback response to the climatic and chemical perturbations of the LPTM GFF 122 1 188 89 Bibcode 2000GFF 122 188Z doi 10 1080 11035890001221188 S2CID 129797785 Speelman E N Van Kempen M M L Barke J Brinkhuis H Reichart G J Smolders A J P Roelofs J G M Sangiorgi F De Leeuw J W Lotter A F Sinninghe Damste J S 2009 The Eocene Arctic Azolla bloom Environmental conditions productivity and carbon drawdown Geobiology 7 2 155 70 Bibcode 2009Gbio 7 155S doi 10 1111 j 1472 4669 2009 00195 x PMID 19323694 S2CID 13206343 Brinkhuis Henk Schouten Stefan Collinson Margaret E Sluijs Appy Sinninghe Damste Jaap S Sinninghe Dickens Gerald R Huber Matthew Cronin Thomas M Onodera Jonaotaro Takahashi Kozo Bujak Jonathan P Stein Ruediger Van Der Burgh Johan Eldrett James S Harding Ian C Lotter Andre F Sangiorgi Francesca Van Konijnenburg Van Cittert Han van Konijnenburg van De Leeuw Jan W Matthiessen Jens Backman Jan Moran Kathryn Expedition 302 Scientists 2006 Episodic fresh surface waters in the Eocene Arctic Ocean Nature 441 7093 606 09 Bibcode 2006Natur 441 606B doi 10 1038 nature04692 hdl 11250 174278 PMID 16752440 S2CID 4412107 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint numeric names authors list link Retallack Gregory J 2001 Cenozoic Expansion of Grasslands and Climatic Cooling The Journal of Geology 109 4 407 26 Bibcode 2001JG 109 407R doi 10 1086 320791 S2CID 15560105 Dutton Jan F Barron Eric J 1997 Miocene to present vegetation changes A possible piece of the Cenozoic cooling puzzle Geology 25 1 39 Bibcode 1997Geo 25 39D doi 10 1130 0091 7613 1997 025 lt 0039 MTPVCA gt 2 3 CO 2 Cronin 2010 p 17 3 Are human activities causing climate change science org au Australian Academy of Science Archived from the original on 8 May 2019 Retrieved 12 August 2017 Antoaneta Yotova ed 2009 Anthropogenic Climate Influences Climate Change Human Systems and Policy Volume I Eolss Publishers ISBN 978 1 905839 02 5 Archived from the original on 4 April 2023 Retrieved 16 August 2020 Steinfeld H P Gerber T Wassenaar V Castel M Rosales C de Haan 2006 Livestock s long shadow Archived from the original on 26 July 2008 Retrieved 21 July 2009 The Editorial Board 28 November 2015 What the Paris Climate Meeting Must Do The New York Times Archived from the original on 29 November 2015 Retrieved 28 November 2015 Volcanic Gases and Their Effects U S Department of the Interior 10 January 2006 Archived from the original on 1 August 2013 Retrieved 21 January 2008 Human Activities Emit Way More Carbon Dioxide Than Do Volcanoes American Geophysical Union 14 June 2011 Archived from the original on 9 May 2013 Retrieved 20 June 2011 a b Milankovitch Cycles and Glaciation University of Montana Archived from the original on 16 July 2011 Retrieved 2 April 2009 Gale Andrew S 1989 A Milankovitch scale for Cenomanian time Terra Nova 1 5 420 25 Bibcode 1989TeNov 1 420G doi 10 1111 j 1365 3121 1989 tb00403 x Same forces as today caused climate changes 1 4 billion years ago sdu dk University of Denmark Archived from the original on 12 March 2015 a b van Nes Egbert H Scheffer Marten Brovkin Victor Lenton Timothy M Ye Hao Deyle Ethan Sugihara George 2015 Causal feedbacks in climate change Nature Climate Change 5 5 445 48 Bibcode 2015NatCC 5 445V doi 10 1038 nclimate2568 ISSN 1758 6798 Box 6 2 What Caused the Low Atmospheric Carbon Dioxide Concentrations During Glacial Times Archived 8 January 2023 at the Wayback Machine in IPCC AR4 WG1 2007 a b Rohli amp Vega 2018 p 296 Willson Richard C Hudson Hugh S 1991 The Sun s luminosity over a complete solar cycle Nature 351 6321 42 44 Bibcode 1991Natur 351 42W doi 10 1038 351042a0 S2CID 4273483 Turner T Edward Swindles Graeme T Charman Dan J Langdon Peter G Morris Paul J Booth Robert K Parry Lauren E Nichols Jonathan E 5 April 2016 Solar cycles or random processes Evaluating solar variability in Holocene climate records Scientific Reports 6 1 23961 doi 10 1038 srep23961 ISSN 2045 2322 PMC 4820721 PMID 27045989 Ribas Ignasi February 2010 The Sun and stars as the primary energy input in planetary atmospheres IAU Symposium 264 Solar and Stellar Variability Impact on Earth and Planets Proceedings of the International Astronomical Union Vol 264 pp 3 18 arXiv 0911 4872 Bibcode 2010IAUS 264 3R doi 10 1017 S1743921309992298 a b Marty B 2006 Water in the Early Earth Reviews in Mineralogy and Geochemistry 62 1 421 450 Bibcode 2006RvMG 62 421M doi 10 2138 rmg 2006 62 18 Watson E B Harrison TM 2005 Zircon Thermometer Reveals Minimum Melting Conditions on Earliest Earth Science 308 5723 841 44 Bibcode 2005Sci 308 841W doi 10 1126 science 1110873 PMID 15879213 S2CID 11114317 Hagemann Steffen G Gebre Mariam Musie Groves David I 1994 Surface water influx in shallow level Archean lode gold deposits in Western Australia Geology 22 12 1067 Bibcode 1994Geo 22 1067H doi 10 1130 0091 7613 1994 022 lt 1067 SWIISL gt 2 3 CO 2 Sagan C G Mullen 1972 Earth and Mars Evolution of Atmospheres and Surface Temperatures Science 177 4043 52 6 Bibcode 1972Sci 177 52S doi 10 1126 science 177 4043 52 PMID 17756316 S2CID 12566286 Archived from the original on 9 August 2010 Retrieved 30 January 2009 Sagan C Chyba C 1997 The Early Faint Sun Paradox Organic Shielding of Ultraviolet Labile Greenhouse Gases Science 276 5316 1217 21 Bibcode 1997Sci 276 1217S doi 10 1126 science 276 5316 1217 PMID 11536805 Schroder K P Connon Smith Robert 2008 Distant future of the Sun and Earth revisited Monthly Notices of the Royal Astronomical Society 386 1 155 63 arXiv 0801 4031 Bibcode 2008MNRAS 386 155S doi 10 1111 j 1365 2966 2008 13022 x S2CID 10073988 a b Miles M G Grainger R G Highwood E J 2004 The significance of volcanic eruption strength and frequency for climate Quarterly Journal of the Royal Meteorological Society 130 602 2361 76 Bibcode 2004QJRMS 130 2361M doi 10 1256 qj 03 60 S2CID 53005926 Volcanic Gases and Climate Change Overview usgs gov USGS Archived from the original on 29 July 2014 Retrieved 31 July 2014 Annexes Archived 6 July 2019 at the Wayback Machine in IPCC AR4 SYR 2008 p 58 Diggles Michael 28 February 2005 The Cataclysmic 1991 Eruption of Mount Pinatubo Philippines U S Geological Survey Fact Sheet 113 97 United States Geological Survey Archived from the original on 25 August 2013 Retrieved 8 October 2009 Diggles Michael The Cataclysmic 1991 Eruption of Mount Pinatubo Philippines usgs gov Archived from the original on 25 August 2013 Retrieved 31 July 2014 Oppenheimer Clive 2003 Climatic environmental and human consequences of the largest known historic eruption Tambora volcano Indonesia 1815 Progress in Physical Geography 27 2 230 59 doi 10 1191 0309133303pp379ra S2CID 131663534 Black Benjamin A Gibson Sally A 2019 Deep Carbon and the Life Cycle of Large Igneous Provinces Elements 15 5 319 324 doi 10 2138 gselements 15 5 319 Wignall P 2001 Large igneous provinces and mass extinctions Earth Science Reviews 53 1 1 33 Bibcode 2001ESRv 53 1W doi 10 1016 S0012 8252 00 00037 4 Graf H F Feichter J Langmann B 1997 Volcanic sulphur emissions Estimates of source strength and its contribution to the global sulphate distribution Journal of Geophysical Research Atmospheres 102 D9 10727 38 Bibcode 1997JGR 10210727G doi 10 1029 96JD03265 hdl 21 11116 0000 0003 2CBB A Forest C E Wolfe J A Molnar P Emanuel K A 1999 Paleoaltimetry incorporating atmospheric physics and botanical estimates of paleoclimate Geological Society of America Bulletin 111 4 497 511 Bibcode 1999GSAB 111 497F doi 10 1130 0016 7606 1999 111 lt 0497 PIAPAB gt 2 3 CO 2 hdl 1721 1 10809 Panama Isthmus that Changed the World NASA Earth Observatory Archived from the original on 2 August 2007 Retrieved 1 July 2008 Haug Gerald H Keigwin Lloyd D 22 March 2004 How the Isthmus of Panama Put Ice in the Arctic Oceanus Woods Hole Oceanographic Institution 42 2 Archived from the original on 5 October 2018 Retrieved 1 October 2013 Bruckschen Peter Oesmanna Susanne Veizer Jan 30 September 1999 Isotope stratigraphy of the European Carboniferous proxy signals for ocean chemistry climate and tectonics Chemical Geology 161 1 3 127 63 Bibcode 1999ChGeo 161 127B doi 10 1016 S0009 2541 99 00084 4 Parrish Judith T 1993 Climate of the Supercontinent Pangea The Journal of Geology The University of Chicago Press 101 2 215 33 Bibcode 1993JG 101 215P doi 10 1086 648217 JSTOR 30081148 S2CID 128757269 Hausfather Zeke 18 August 2017 Explainer Why the sun is not responsible for recent climate change Carbon Brief Archived from the original on 17 March 2023 Retrieved 5 September 2019 Pierce J R 2017 Cosmic rays aerosols clouds and climate Recent findings from the CLOUD experiment Journal of Geophysical Research Atmospheres 122 15 8051 55 Bibcode 2017JGRD 122 8051P doi 10 1002 2017JD027475 ISSN 2169 8996 S2CID 125580175 Brugger Julia Feulner Georg Petri Stefan April 2017 Severe environmental effects of Chicxulub impact imply key role in end Cretaceous mass extinction 19th EGU General Assembly EGU2017 proceedings from the conference 23 28 April 2017 vol 19 Vienna Austria p 17167 Bibcode 2017EGUGA 1917167B a href Template Citation html title Template Citation citation a CS1 maint location missing publisher link Burroughs 2001 p 232 Hadlington Simon 9 May 2013 Mineral dust plays key role in cloud formation and chemistry Chemistry World Archived from the original on 24 October 2022 Retrieved 5 September 2019 a href Template Cite web html title Template Cite web cite web a CS1 maint numeric names authors list link Mahowald Natalie Albani Samuel Kok Jasper F Engelstaeder Sebastian Scanza Rachel Ward Daniel S Flanner Mark G 1 December 2014 The size distribution of desert dust aerosols and its impact on the Earth system Aeolian Research 15 53 71 Bibcode 2014AeoRe 15 53M doi 10 1016 j aeolia 2013 09 002 ISSN 1875 9637 New M Todd M Hulme M Jones P December 2001 Review Precipitation measurements and trends in the twentieth century International Journal of Climatology 21 15 1889 922 Bibcode 2001IJCli 21 1889N doi 10 1002 joc 680 S2CID 56212756 a b Demenocal P B 2001 Cultural Responses to Climate Change During the Late Holocene PDF Science 292 5517 667 73 Bibcode 2001Sci 292 667D doi 10 1126 science 1059827 PMID 11303088 S2CID 18642937 Archived from the original PDF on 17 December 2008 Retrieved 28 August 2015 Sindbaek S M 2007 Networks and nodal points the emergence of towns in early Viking Age Scandinavia Antiquity 81 311 119 32 doi 10 1017 s0003598x00094886 Dominic F Burns S J Neff U Mudulsee M Mangina A Matter A April 2004 Palaeoclimatic interpretation of high resolution oxygen isotope profiles derived from annually laminated speleothems from Southern Oman Quaternary Science Reviews 23 7 8 935 45 Bibcode 2004QSRv 23 935F doi 10 1016 j quascirev 2003 06 019 Hughes Malcolm K Swetnam Thomas W Diaz Henry F eds 2010 Dendroclimatology progress and prospect Developments in Paleoenvironmental Research Vol 11 New York Springer Science amp Business Media ISBN 978 1 4020 4010 8 Langdon P G Barber K E Lomas Clarke S H Lomas Clarke S H August 2004 Reconstructing climate and environmental change in northern England through chironomid and pollen analyses evidence from Talkin Tarn Cumbria Journal of Paleolimnology 32 2 197 213 Bibcode 2004JPall 32 197L doi 10 1023 B JOPL 0000029433 85764 a5 S2CID 128561705 Birks H H March 2003 The importance of plant macrofossils in the reconstruction of Lateglacial vegetation and climate examples from Scotland western Norway and Minnesota US PDF Quaternary Science Reviews 22 5 7 453 73 Bibcode 2003QSRv 22 453B doi 10 1016 S0277 3791 02 00248 2 hdl 1956 387 Archived from the original PDF on 11 June 2007 Retrieved 20 April 2018 Miyoshi N Fujiki Toshiyuki Morita Yoshimune 1999 Palynology of a 250 m core from Lake Biwa a 430 000 year record of glacial interglacial vegetation change in Japan Review of Palaeobotany and Palynology 104 3 4 267 83 Bibcode 1999RPaPa 104 267M doi 10 1016 S0034 6667 98 00058 X Prentice I Colin Bartlein Patrick J Webb Thompson 1991 Vegetation and Climate Change in Eastern North America Since the Last Glacial Maximum Ecology 72 6 2038 56 doi 10 2307 1941558 JSTOR 1941558 Coope G R Lemdahl G Lowe J J Walkling A 4 May 1999 Temperature gradients in northern Europe during the last glacial Holocene transition 14 9 14 C kyr BP interpreted from coleopteran assemblages Journal of Quaternary Science 13 5 419 33 Bibcode 1998JQS 13 419C doi 10 1002 SICI 1099 1417 1998090 13 5 lt 419 AID JQS410 gt 3 0 CO 2 D a b c Adams J M Faure H eds 1997 Global land environments since the last interglacial Tennessee Oak Ridge National Laboratory Archived from the original on 16 January 2008 QEN members Ochoa Hueso R Delgado Baquerizo N King PTA Benham M Arca V Power SA 2019 Ecosystem type and resource quality are more important than global change drivers in regulating early stages of litter decomposition Soil Biology and Biochemistry 129 144 52 doi 10 1016 j soilbio 2018 11 009 hdl 10261 336676 S2CID 92606851 Kinver Mark 15 November 2011 UK trees fruit ripening 18 days earlier Bbc co uk Archived from the original on 17 March 2023 Retrieved 1 November 2012 a b Sahney S Benton M J Falcon Lang H J 2010 Rainforest collapse triggered Pennsylvanian tetrapod diversification in Euramerica PDF Geology 38 12 1079 82 Bibcode 2010Geo 38 1079S doi 10 1130 G31182 1 Archived from the original on 17 March 2023 Retrieved 27 November 2013 Bachelet D Neilson R Lenihan J M Drapek R J 2001 Climate Change Effects on Vegetation Distribution and Carbon Budget in the United States Ecosystems 4 3 164 85 doi 10 1007 s10021 001 0002 7 S2CID 15526358 Burroughs 2007 p 273 Millington Rebecca Cox Peter M Moore Jonathan R Yvon Durocher Gabriel 10 May 2019 Modelling ecosystem adaptation and dangerous rates of global warming Emerging Topics in Life Sciences 3 2 221 31 doi 10 1042 ETLS20180113 hdl 10871 36988 ISSN 2397 8554 PMID 33523155 S2CID 150221323 Burroughs 2007 p 267 Seiz G N Foppa 2007 The activities of the World Glacier Monitoring Service WGMS PDF Report Archived from the original PDF on 25 March 2009 Retrieved 21 June 2009 International Stratigraphic Chart International Commission on Stratigraphy 2008 Archived from the original on 15 October 2011 Retrieved 3 October 2011 Burroughs 2007 p 279 Hansen James Science Briefs Earth s Climate History NASA GISS Archived from the original on 24 July 2011 Retrieved 25 April 2013 Belt Simon T Cabedo Sanz Patricia Smik Lukas et al 2015 Identification of paleo Arctic winter sea ice limits and the marginal ice zone Optimised biomarker based reconstructions of late Quaternary Arctic sea ice Earth and Planetary Science Letters 431 127 39 Bibcode 2015E amp PSL 431 127B doi 10 1016 j epsl 2015 09 020 hdl 10026 1 4335 ISSN 0012 821X Warren Stephen G Voigt Aiko Tziperman Eli et al 1 November 2017 Snowball Earth climate dynamics and Cryogenian geology geobiology Science Advances 3 11 e1600983 Bibcode 2017SciA 3E0983H doi 10 1126 sciadv 1600983 ISSN 2375 2548 PMC 5677351 PMID 29134193 Caballero R Huber M 2013 State dependent climate sensitivity in past warm climates and its implications for future climate projections Proceedings of the National Academy of Sciences 110 35 14162 67 Bibcode 2013PNAS 11014162C doi 10 1073 pnas 1303365110 ISSN 0027 8424 PMC 3761583 PMID 23918397 Hansen James Sato Makiko Russell Gary Kharecha Pushker 2013 Climate sensitivity sea level and atmospheric carbon dioxide Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences 371 2001 20120294 arXiv 1211 4846 Bibcode 2013RSPTA 37120294H doi 10 1098 rsta 2012 0294 PMC 3785813 PMID 24043864 a b McInherney F A Wing S 2011 A perturbation of carbon cycle climate and biosphere with implications for the future Annual Review of Earth and Planetary Sciences 39 489 516 Bibcode 2011AREPS 39 489M doi 10 1146 annurev earth 040610 133431 Archived from the original on 14 September 2016 Retrieved 26 October 2019 Westerhold T Rohl U Raffi I Fornaciari E Monechi S Reale V Bowles J Evans H F 2008 Astronomical calibration of the Paleocene time PDF Palaeogeography Palaeoclimatology Palaeoecology 257 4 377 403 Bibcode 2008PPP 257 377W doi 10 1016 j palaeo 2007 09 016 Archived PDF from the original on 9 August 2017 Burroughs 2007 pp 190 91 Ivany Linda C Pietsch Carlie Handley John C Lockwood Rowan Allmon Warren D Sessa Jocelyn A 1 September 2018 Little lasting impact of the Paleocene Eocene Thermal Maximum on shallow marine molluscan faunas Science Advances 4 9 eaat5528 Bibcode 2018SciA 4 5528I doi 10 1126 sciadv aat5528 ISSN 2375 2548 PMC 6124918 PMID 30191179 Haerter Jan O Moseley Christopher Berg Peter 2013 Strong increase in convective precipitation in response to higher temperatures Nature Geoscience 6 3 181 85 Bibcode 2013NatGe 6 181B doi 10 1038 ngeo1731 ISSN 1752 0908 Kaufman Darrell McKay Nicholas Routson Cody Erb Michael Datwyler Christoph Sommer Philipp S Heiri Oliver Davis Basil 30 June 2020 Holocene global mean surface temperature a multi method reconstruction approach Scientific Data 7 1 201 Bibcode 2020NatSD 7 201K doi 10 1038 s41597 020 0530 7 ISSN 2052 4463 PMC 7327079 PMID 32606396 Zemp M I Roer A Kaab M Hoelzle F Paul W Haeberli 2008 United Nations Environment Programme Global Glacier Changes facts and figures PDF Report Archived from the original PDF on 25 March 2009 Retrieved 21 June 2009 EPA OA US July 2016 Climate Change Indicators Glaciers US EPA Archived from the original on 29 September 2019 Retrieved 26 January 2018 Land ice NASA Global Climate Change Archived from the original on 23 February 2017 Retrieved 10 December 2017 Shaftel Holly ed Climate Change How do we know NASA Global Climate Change Earth Science Communications Team at NASA s Jet Propulsion Laboratory Archived from the original on 18 December 2019 Retrieved 16 December 2017 GISS Surface Temperature Analysis v4 Annual Mean Temperature Change over Land and over Ocean NASA GISS Archived from the original on 16 April 2020 a b Harvey Chelsea 1 November 2018 The Oceans Are Heating Up Faster Than Expected Scientific American Archived from the original on 3 March 2020 Data from NASA GISS GISS Surface Temperature Analysis v4 Annual Mean Temperature Change for Hemispheres NASA GISS Archived from the original on 16 April 2020 a b Freedman Andrew 9 April 2013 In Warming Northern Hemisphere is Outpacing the South Climate Central Archived from the original on 31 October 2019 a b GISS Surface Temperature Analysis v4 Temperature Change for Three Latitude Bands NASA GISS Archived from the original on 16 April 2020 a b Hawkins Ed 12 September 2019 Atmospheric temperature trends Climate Lab Book Archived from the original on 12 September 2019 Higher altitude cooling differences attributed to ozone depletion and greenhouse gas increases spikes occurred with volcanic eruptions of 1982 83 El Chichon and 1991 92 Pinatubo a b Meduna Veronika 17 September 2018 The climate visualisations that leave no room for doubt or denial The Spinoff New Zealand Archived from the original on 17 May 2019 Climate at a Glance Global Time Series NCDC NOAA Archived from the original on 23 February 2020 a b Hawkins Ed 10 March 2020 From the familiar to the unknown Climate Lab Book professional blog Archived from the original on 23 April 2020 Direct link to image Hawkins credits Berkeley Earth for data The emergence of observed temperature changes over both land and ocean is clearest in tropical regions in contrast to the regions of largest change which are in the northern extra tropics As an illustration northern America has warmed more than tropical America but the changes in the tropics are more apparent and have more clearly emerged from the range of historical variability The year to year variations in the higher latitudes have made it harder to distinguish the long term changes a b Lenton Timothy M Rockstrom Johan Gaffney Owen Rahmstorf Stefan Richardson Katherine Steffen Will Schellnhuber Hans Joachim 27 November 2019 Climate tipping points too risky to bet against Nature 575 7784 592 595 Bibcode 2019Natur 575 592L doi 10 1038 d41586 019 03595 0 hdl 10871 40141 PMID 31776487 Correction dated 9 April 2020ReferencesCronin Thomas N 2010 Paleoclimates understanding climate change past and present New York Columbia University Press ISBN 978 0 231 14494 0 IPCC 2007 Solomon S Qin D Manning M Chen Z et al eds Climate Change 2007 The Physical Science Basis PDF Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press ISBN 978 0 521 88009 1 pb 978 0 521 70596 7 IPCC 2008 The Core Writing Team Pachauri R K Reisinger A R eds Climate Change 2008 Synthesis Report Contribution of Working Groups I II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change Geneva Switzerland IPCC ISBN 978 92 9169 122 7 permanent dead link Burroughs William James 2001 Climate Change A multidisciplinary approach Cambridge Cambridge university press ISBN 0521567718 Burroughs William James 2007 Climate Change A multidisciplinary approach Cambridge Cambridge University Press ISBN 978 0 511 37027 4 Ruddiman William F 2008 Earth s climate Past and Future New York W H Freeman and Company ISBN 978 0716784906 Rohli Robert V Vega Anthony J 2018 Climatology 4th ed Jones amp Bartlett Learning ISBN 978 1284126563 External linksGlobal Climate Change from NASA US Intergovernmental Panel on Climate Change IPCC Climate Variability Archived 30 May 2023 at the Wayback Machine NASA Science Climate Change and Variability National Centers for Environmental Information Archived 21 September 2021 at the Wayback Machine Retrieved from https en wikipedia org w index php title Climate variability and change amp oldid 1195162330, wikipedia, wiki, book, books, library,

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