fbpx
Wikipedia

Carbon sink

January 31, 2023

A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide (CO2) from the atmosphere.[1]

This diagram of the fast carbon cycle shows the movement of carbon between land, atmosphere, soil and oceans in billions of tons of carbon per year. Yellow numbers are natural fluxes, red are human contributions in billions of tons of carbon per year. White numbers indicate stored carbon.

Globally, the two most important carbon sinks are vegetation and the ocean.[2] Public awareness of the significance of CO2 sinks has grown since passage of the 1997 Kyoto Protocol, which promotes their use as a form of carbon offset.[3] There are also different strategies used to enhance this process. Soil is an important carbon storage medium. Much of the organic carbon retained in the soil of agricultural areas has been depleted due to intensive farming. "Blue carbon" designates carbon that is fixed via the ocean ecosystems. Mangroves, salt marshes and seagrasses make up a majority of ocean plant life and store large quantities of carbon.

Many efforts are being made to enhance natural sequestration in soils and the oceans.[1] In addition, a range of artificial sequestration initiatives are underway such as changed building construction materials, carbon capture and storage and geological sequestration.[4][5]

General

 
Air-sea exchange of CO2

Increase in atmospheric carbon dioxide means increase in global temperature. The amount of carbon dioxide varies naturally in a dynamic equilibrium with photosynthesis of land plants. The natural sinks are:

  • Soil is a carbon store and active carbon sink.[6]
  • Photosynthesis by terrestrial plants with grass and trees allows them to serve as carbon sinks during growing seasons.
  • Absorption of carbon dioxide by the oceans via solubility and biological pumps

While the creation of artificial sinks has been discussed, no major artificial systems remove carbon from the atmosphere on a material scale yet.[7]

Carbon sources include the combustion of fossil fuels (coal, natural gas, and oil) by humans for energy and transportation.[8]

Kyoto Protocol

The Kyoto Protocol was an international agreement that aimed at reducing carbon dioxide (CO2) emissions and the presence of greenhouse gases (GHG) in the atmosphere. The essential tenet of the Kyoto Protocol was that industrialized nations needed to reduce their CO2 emissions. Because growing vegetation takes in carbon dioxide, the Kyoto Protocol allows Annex I countries with large areas of growing forests to issue Removal Units to recognize the sequestration of carbon. The additional units make it easier for them to achieve their target emission levels. It is estimated that forests absorb between 10 to 20 tonnes per hectare (4.0 to 8.0 long ton/acre; 4.5 to 8.9 short ton/acre) each year, through photosynthetic conversion into starch, cellulose, lignin, and other components of wooden biomass. While this has been well documented for temperate forests and plantations, the fauna of the tropical forests place some limitations for such global estimates.[9]

Some countries seek to trade emission rights in carbon emission markets, purchasing the unused carbon emission allowances of other countries. If overall limits on greenhouse gas emission are put into place, cap and trade market mechanisms are purported to find cost-effective ways to reduce emissions.[10] There is as yet no carbon audit regime for all such markets globally, and none is specified in the Kyoto Protocol. National carbon emissions are self-declared.

In the Clean Development Mechanism, only afforestation and reforestation are eligible to produce certified emission reductions (CERs) in the first commitment period of the Kyoto Protocol (2008–2012). Forest conservation activities or activities avoiding deforestation, which would result in emission reduction through the conservation of existing carbon stocks, are not eligible at this time.[11] Also, agricultural carbon sequestration is not possible yet.[12]

Storage in terrestrial and marine environments

Soils

Soils represent a short to long-term carbon storage medium, and contain more carbon than all terrestrial vegetation and the atmosphere combined.[13][14][15] Plant litter and other biomass including charcoal accumulates as organic matter in soils, and is degraded by chemical weathering and biological degradation. More recalcitrant organic carbon polymers such as cellulose, hemi-cellulose, lignin, aliphatic compounds, waxes and terpenoids are collectively retained as humus.[16] Organic matter tends to accumulate in litter and soils of colder regions such as the boreal forests of North America and the Taiga of Russia. Leaf litter and humus are rapidly oxidized and poorly retained in sub-tropical and tropical climate conditions due to high temperatures and extensive leaching by rainfall. Areas where shifting cultivation or slash and burn agriculture are practiced are generally only fertile for two to three years before they are abandoned. These tropical jungles are similar to coral reefs in that they are highly efficient at conserving and circulating necessary nutrients, which explains their lushness in a nutrient desert.[17] Much organic carbon retained in many agricultural areas worldwide has been severely depleted due to intensive farming practices.[18]

Grasslands contribute to soil organic matter, stored mainly in their extensive fibrous root mats. Due in part to the climatic conditions of these regions (e.g. cooler temperatures and semi-arid to arid conditions), these soils can accumulate significant quantities of organic matter. This can vary based on rainfall, the length of the winter season, and the frequency of naturally occurring lightning-induced grass-fires. While these fires release carbon dioxide, they improve the quality of the grasslands overall, in turn increasing the amount of carbon retained in the humic material. They also deposit carbon directly to the soil in the form of Biochar that does not significantly degrade back to carbon dioxide.[19]

Forest fires release absorbed carbon back into the atmosphere,[20] as does deforestation due to rapidly increased oxidation of soil organic matter.[21]

Organic matter in peat bogs undergoes slow anaerobic decomposition below the surface. This process is slow enough that in many cases the bog grows rapidly and fixes more carbon from the atmosphere than is released. Over time, the peat grows deeper. Peat bogs hold approximately one-quarter of the carbon stored in land plants and soils.[22]

Under some conditions, forests and peat bogs may become sources of CO2, such as when a forest is flooded by the construction of a hydroelectric dam. Unless the forests and peat are harvested before flooding, the rotting vegetation is a source of CO2 and methane comparable in magnitude to the amount of carbon released by a fossil-fuel powered plant of equivalent power.[23]

Regenerative agriculture

See also: Biosequestration

Current agricultural practices lead to carbon loss from soils. It has been suggested that improved farming practices could improve the capacity of the soil carbon sponge to hold carbon and water. Present worldwide practises of overgrazing are substantially reducing many grasslands' performance as soil carbon sponges.[24] The Rodale Institute says that regenerative agriculture, if practiced on the planet's tillable land of 15 million km2 (3.6 billion acres), could sequester up to 40% of current CO2 emissions.[25] They claim that agricultural carbon sequestration has the potential to mitigate global warming. When using biologically based regenerative practices, this dramatic benefit can be accomplished with no decrease in yields or farmer profits.[26] Organically managed soils can convert carbon dioxide from a greenhouse gas into a food-producing asset.[18]

In 2006, U.S. carbon dioxide emissions, largely from fossil fuel combustion, were estimated at nearly 5.9 billion tonnes (6.5 billion short tons).[27] If a 220 tonnes per square kilometre (2,000 lb/acre) per year sequestration rate was achieved on all 1.76 million km2 (434 million acres) of cropland in the United States, nearly 1.5 billion t (1.6 billion short tons) of carbon dioxide would be sequestered per year, mitigating close to one quarter of the country's total fossil fuel emissions.[18]

Riverine transport

 
How carbon moves from inland waters to the ocean
Carbon dioxide exchange, photosynthetic production and respiration of terrestrial vegetation, rock weathering, and sedimentation occur in terrestrial ecosystems. Carbon transports to the ocean through the land-river-estuary continuum in the form of organic carbon and inorganic carbon. Carbon exchange at the air-water interface, transportation, transformation and sedimentation occur in oceanic ecosystems.[28]

Terrestrial and marine ecosystems are chiefly connected through riverine transport, which acts as the main channel through which erosive terrestrially derived substances enter into oceanic systems. Material and energy exchanges between the terrestrial biosphere and the lithosphere as well as organic carbon fixation and oxidation processes together regulate ecosystem carbon and dioxygen (O2) pools.[28]

Riverine transport, being the main connective channel of these pools, will act to transport net primary productivity (primarily in the form of dissolved organic carbon (DOC) and particulate organic carbon (POC)) from terrestrial to oceanic systems.[29] During transport, part of DOC will rapidly return to the atmosphere through redox reactions, causing "carbon degassing" to occur between land-atmosphere storage layers.[30][31] The remaining DOC and dissolved inorganic carbon (DIC) are also exported to the ocean.[32][33][34] Currently (2015) inorganic and organic carbon export fluxes from global rivers to the ocean amount to 0.50–0.70 Pg C y−1 and 0.15–0.35 Pg C y−1 respectively.[33] On the other hand, POC can remain buried in sediment over an extensive period, and the annual global terrestrial to oceanic POC flux has been estimated at 0.20 (+0.13,-0.07) Gg C y−1.[35][28]

Oceans

This section is an excerpt from Blue carbon.[edit]
 
Estimates of the economic value of blue carbon ecosystems per hectare. Based on 2009 data from UNEP/GRID-Arendal.[36][37]
Blue carbon refers to organic carbon that is captured and stored by the world's oceanic and coastal ecosystems, mostly by algae, seagrasses, macroalgae, mangroves, salt marshes and other plants in coastal wetlands.[37] The term "blue carbon" was coined in 2009 to highlight the contribution of coastal vegetated ecosystems to climate change mitigation.[38] Because oceans cover 70% of the planet, there is increasing industry interest in developing blue carbon potential.[39] Research is ongoing, and while in some cases it has been found that these types of ecosystems remove far more carbon per area than terrestrial forests, the effectiveness of blue carbon as a carbon dioxide removal solution remains highly contested.[40][39][41]

Enhancing natural sequestration

Forests

See also: Biosequestration

Forests can be carbon stores,[42][43][44] and they are carbon dioxide sinks when they are increasing in density or area. In Canada's boreal forests as much as 80% of the total carbon is stored in the soils as dead organic matter.[45] A 40-year study of African, Asian, and South American tropical forests by the University of Leeds showed that tropical forests absorb about 18% of all carbon dioxide added by fossil fuels. For the last three decades, the amount of carbon absorbed by the world's intact tropical forests has fallen, according to a study published in 2020 in the journal Nature.

 
Proportion of carbon stock in forest carbon pools, 2020[46]

The total carbon stock in forests decreased from 668 gigatonnes in 1990 to 662 gigatonnes in 2020.[47] However, another study finds that the leaf area index has increased globally since 1981, which was responsible for 12.4% of the accumulated terrestrial carbon sink from 1981 to 2016. The CO2 fertilization effect, on the other hand, was responsible for 47% of the sink, while climate change reduced the sink by 28.6%.[48]

In 2019 they took up a third less carbon than they did in the 1990s, due to higher temperatures, droughts and deforestation. The typical tropical forest may become a carbon source by the 2060s.[49] Truly mature tropical forests, by definition, grow rapidly, with each tree producing at least 10 new trees each year. Based on studies by FAO and UNEP, it has been estimated that Asian forests absorb about 5 tonnes of carbon dioxide per hectare each year. The global cooling effect of carbon sequestration by forests is partially counterbalanced in that reforestation can decrease the reflection of sunlight (albedo). Mid-to-high-latitude forests have a much lower albedo during snow seasons than flat ground, thus contributing to warming. Modeling that compares the effects of albedo differences between forests and grasslands suggests that expanding the land area of forests in temperate zones offers only a temporary cooling benefit.[50][51][52][53]

In the United States in 2004 (the most recent year for which EPA statistics[54] are available), forests sequestered 10.6% (637 megatonnes)[55] of the carbon dioxide released in the United States by the combustion of fossil fuels (coal, oil, and natural gas; 5,657 megatonnes[56]). Urban trees sequestered another 1.5% (88 megatonnes).[55] To further reduce U.S. carbon dioxide emissions by 7%, as stipulated by the Kyoto Protocol, would require the planting of "an area the size of Texas [8% of the area of Brazil] every 30 years".[57] Carbon offset programs are planting millions of fast-growing trees per year to reforest tropical lands, for as little as $0.10 per tree; over their typical 40-year lifetime, one million of these trees will fix 1 a million tons of carbon dioxide.[58][59] In Canada, reducing timber harvesting would have very little impact on carbon dioxide emissions because of the combination of harvest and stored carbon in manufactured wood products along with the regrowth of the harvested forests. Additionally, the amount of carbon released from harvesting is small compared to the amount of carbon lost each year to forest fires and other natural disturbances.[45]

The Intergovernmental Panel on Climate Change concluded that "a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks, while producing an annual sustained yield of timber fibre or energy from the forest, will generate the largest sustained mitigation benefit".[60] Sustainable management practices keep forests growing at a higher rate over a potentially longer period of time, thus providing net sequestration benefits in addition to those of unmanaged forests.[61]

Life expectancy of forests varies throughout the world, influenced by tree species, site conditions and natural disturbance patterns. In some forests, carbon may be stored for centuries, while in other forests, carbon is released with frequent stand replacing fires. Forests that are harvested prior to stand replacing events allow for the retention of carbon in manufactured forest products such as lumber.[62] However, only a portion of the carbon removed from logged forests ends up as durable goods and buildings. The remainder ends up as sawmill by-products such as pulp, paper and pallets, which often end with incineration (resulting in carbon release into the atmosphere) at the end of their lifecycle. For instance, of the 1,692 megatonnes of carbon harvested from forests in Oregon and Washington from 1900 to 1992, only 23% is in long-term storage in forest products.[63]

Oceans

See also: Iron fertilization, Enhanced weathering, and Ocean nourishment

One way to increase the carbon sequestration efficiency of the oceans is to add micrometre-sized iron particles in the form of either hematite (iron oxide) or melanterite (iron sulfate) to certain regions of the ocean. This has the effect of stimulating growth of plankton. Iron is an important nutrient for phytoplankton, usually made available via upwelling along the continental shelves, inflows from rivers and streams, as well as deposition of dust suspended in the atmosphere. Natural sources of ocean iron have been declining in recent decades, contributing to an overall decline in ocean productivity.[64] Yet in the presence of iron nutrients plankton populations quickly grow, or 'bloom', expanding the base of biomass productivity throughout the region and removing significant quantities of CO2 from the atmosphere via photosynthesis. A test in 2002 in the Southern Ocean around Antarctica suggests that between 10,000 and 100,000 carbon atoms are sunk for each iron atom added to the water.[65] Application of iron nutrients in select parts of the oceans, at appropriate scales, could have the combined effect of restoring ocean productivity while at the same time mitigating the effects of human caused emissions of carbon dioxide to the atmosphere.[64]

Because the effect of periodic small scale phytoplankton blooms on ocean ecosystems is unclear, more studies would be helpful. Phytoplankton have a complex effect on cloud formation via the release of substances such as dimethyl sulfide (DMS) that are converted to sulfate aerosols in the atmosphere, providing cloud condensation nuclei, or CCN.[66]

Other nutrients such as nitrates, phosphates, and silica as well as iron may cause ocean fertilization. There has been some speculation that using pulses of fertilization (around 20 days in length) may be more effective at getting carbon to ocean floor than sustained fertilization.[67]

There is some controversy over seeding the oceans with iron however, due to the potential for increased toxic phytoplankton growth (e.g. "red tide"), declining water quality due to overgrowth, and increasing anoxia in areas harming other sea-life such as zooplankton, fish, coral, etc.[68][69]

Soils

Since the 1850s, a large proportion of the world's grasslands have been tilled and converted to croplands, allowing the rapid oxidation of large quantities of soil organic carbon. However, in the United States in 2004 (the most recent year for which EPA statistics are available), agricultural soils including pasture land sequestered 0.8% (46 megatonne)[55] as much carbon as was released in the United States by the combustion of fossil fuels (5,988 megatonne).[56] The annual amount of this sequestration has been gradually increasing since 1998.[70][55]

Methods that significantly enhance carbon sequestration in soil include no-till farming, residue mulching, cover cropping, and crop rotation, all of which are more widely used in organic farming than in conventional farming.[71][72] Because only 5% of US farmland currently uses no-till and residue mulching, there is a large potential for carbon sequestration.[73] Conversion to pastureland, particularly with good management of grazing, can sequester even more carbon in the soil.

Terra preta, an anthropogenic, high-carbon soil, is also being investigated as a sequestration mechanism. By pyrolysing biomass, about half of its carbon can be reduced to charcoal, which can persist in the soil for centuries, and makes a useful soil amendment, especially in tropical soils (biochar or agrichar).[74][75]

"For most of human history, permafrost has been Earth's largest terrestrial carbon sink, trapping plant and animal material in its frozen layers for centuries. It currently stores about 1,600 billion tonnes of carbon—more than twice the amount in the atmosphere today. But thanks to rising temperatures, permafrost is fracturing and disappearing".[76] Sergey Zimov has proposed to restore and protect this major carbon sequestration mechanism via restoration of grassland and large arctic mammalian herbivores.[77]

Savanna

Controlled burns on far north Australian savannas can result in an overall carbon sink. One working example is the West Arnhem Fire Management Agreement, started to bring "strategic fire management across 28,000 km2 of Western Arnhem Land". Deliberately starting controlled burns early in the dry season results in a mosaic of burnt and unburnt country which reduces the area of burning compared with stronger, late dry season fires. In the early dry season there are higher moisture levels, cooler temperatures, and lighter wind than later in the dry season; fires tend to go out overnight. Early controlled burns also results in a smaller proportion of the grass and tree biomass being burnt.[78] Emission reductions of 256,000 tonnes of CO2 have been made as of 2007.[79]

Artificial sequestration

For carbon to be sequestered artificially (i.e. not using the natural processes of the carbon cycle) it must first be captured, or it must be significantly delayed or prevented from being re-released into the atmosphere (by combustion, decay, etc.) from an existing carbon-rich material, by being incorporated into an enduring usage (such as in construction). Thereafter it can be passively stored or remain productively utilized over time in a variety of ways. For instance, upon harvesting, wood (as a carbon-rich material) can be immediately burned or otherwise serve as a fuel, returning its carbon to the atmosphere, or it can be incorporated into construction or a range of other durable products, thus sequestering its carbon over years or even centuries.[80]

A very carefully designed and durable, energy-efficient and energy-capturing building has the potential to sequester (in its carbon-rich construction materials), as much as or more carbon than was released by the acquisition and incorporation of all its materials and than will be released by building-function "energy-imports" during the structure's (potentially multi-century) existence. Such a structure might be termed "carbon neutral" or even "carbon negative". Building construction and operation (electricity usage, heating, etc.) are estimated to contribute nearly half of the annual human-caused carbon additions to the atmosphere.[81]

Natural-gas purification plants often already have to remove carbon dioxide, either to avoid dry ice clogging gas tankers or to prevent carbon-dioxide concentrations exceeding the 3% maximum permitted on the natural-gas distribution grid.[82]

Buildings

 
Mjøstårnet, one of the tallest timber buildings, at its opening 2019

According to an international team of interdisciplinary scientists in a 2020 study, broad-base adoption of mass timber and their substitution for steel and concrete in new mid-rise construction projects over the next few decades has the potential to turn timber buildings into a global carbon sink, as they store the carbon dioxide taken up from the air by trees that are harvested and used as mass timber. Noting the demographic need for new urban construction for the next thirty years, the team analyzed four scenarios for the transition to mass-timber new mid-rise construction. Assuming business as usual, only 0.5% of new buildings worldwide would be constructed with timber by 2050 (scenario 1). This could be driven up to 10% (scenario 2) or 50% (scenario 3), assuming mass timber manufacturing would increase as a material revolution replacing cement and steel in urban construction by wood scales up accordingly. Lastly, if countries with current low industrialization level, e.g., Africa, Oceania, and parts of Asia, would also make the transition to timber (including bamboo), then even 90% timber by 2050 (scenario 4) is conceivable. This could result in storing between 10 million tons of carbon per year in the lowest scenario and close to 700 million tons in the highest scenario. The study found that this potential could be realized under two conditions. First, the harvested forests would need to be sustainably managed, governed, and used. Second, wood from demolished timber buildings would need to be reused or preserved on land in various forms.[83]

Direct air capture

This section is an excerpt from Direct air capture.[edit]
 
Flow diagram of direct air capture process using sodium hydroxide as the absorbent and including solvent regeneration

Direct air capture (DAC) is a process of capturing carbon dioxide (CO2) directly from the ambient air (as opposed to capturing from point sources, such as a cement factory or biomass power plant) and generating a concentrated stream of CO2 for sequestration or utilization or production of carbon-neutral fuel and windgas. Carbon dioxide removal is achieved when ambient air makes contact with chemical media, typically an aqueous alkaline solvent[84] or sorbents.[85] These chemical media are subsequently stripped of CO2 through the application of energy (namely heat), resulting in a CO2 stream that can undergo dehydration and compression, while simultaneously regenerating the chemical media for reuse.

DAC was suggested in 1999 by Klaus S. Lackner and is still in development.[86][87] Several commercial plants are planned or in operation in Europe and the US. Large-scale DAC deployment may be accelerated when connected with economical applications or policy incentives.

In contrast to carbon capture and storage (CCS) which captures emissions from a point source such as a factory, DAC reduces the carbon dioxide concentration in the atmosphere as a whole.[88] Typically, CCS is recommended for large and stationary sources of CO2 rather than distributed and movable ones. On the contrary, DAC has no limitation on sources.[89] When combined with long-term storage of CO2, DAC is known as direct air carbon capture and storage (DACCS or DACS[90]). DACCS can act as a carbon dioxide removal mechanism, although as of 2022 it has yet to be profitable because the cost per tonne of carbon dioxide is several times the carbon price.

Oceans

Another proposed form of carbon sequestration in the ocean is direct injection. In this method, carbon dioxide is pumped directly into the water at depth, and expected to form "lakes" of liquid CO2 at the bottom. Experiments carried out in moderate to deep waters (350–3,600 metres (1,150–11,810 ft)) indicate that the liquid CO2 reacts to form solid CO2 clathrate hydrates, which gradually dissolve in the surrounding waters.[91]

This method, too, has potentially dangerous environmental consequences. The carbon dioxide does react with the water to form carbonic acid, H2CO3; however, most (as much as 99%) remains as dissolved molecular CO2. The equilibrium would no doubt be quite different[vague] under the high pressure conditions in the deep ocean. In addition, if deep-sea bacterial methanogens that reduce carbon dioxide were to encounter the carbon dioxide sinks, levels of methane gas may increase, leading to the generation of an even worse greenhouse gas.[92] The resulting environmental effects on benthic life forms of the bathypelagic, abyssopelagic and hadopelagic zones are unknown. Even though life appears to be rather sparse in the deep ocean basins, energy and chemical effects in these deep basins could have far-reaching implications. Much more work is needed here to define the extent of the potential problems.

Carbon storage in or under oceans may not be compatible with the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter.[93]

An additional method of long-term ocean-based sequestration is to gather crop residue such as corn stalks or excess hay into large weighted bales of biomass and deposit it in the alluvial fan areas of the deep ocean basin. Dropping these residues in alluvial fans would cause the residues to be quickly buried in silt on the sea floor, sequestering the biomass for very long time spans. Alluvial fans exist in all of the world's oceans and seas where river deltas fall off the edge of the continental shelf such as the Mississippi alluvial fan in the gulf of Mexico and the Nile alluvial fan in the Mediterranean Sea. A downside, however, would be an increase in aerobic bacteria growth due to the introduction of biomass, leading to more competition for oxygen resources in the deep sea, similar to the oxygen minimum zone.[94]

Geological sequestration

The method of geo-sequestration or geological storage involves injecting carbon dioxide directly into underground geological formations.[95] Declining oil fields, saline aquifers, and unmineable coal seams have been suggested as storage sites. Caverns and old mines that are commonly used to store natural gas are not considered, because of a lack of storage safety.

CO2 has been injected into declining oil fields for more than 40 years, to increase oil recovery. This option is attractive because the storage costs are offset by the sale of additional oil that is recovered. Typically, 10–15% additional recovery of the original oil in place is possible. Further benefits are the existing infrastructure and the geophysical and geological information about the oil field that is available from the oil exploration. Another benefit of injecting CO2 into oil fields is that CO2 is soluble in oil. Dissolving CO2 in oil lowers the viscosity of the oil and reduces its interfacial tension which increases the oils mobility. All oil fields have a geological barrier preventing upward migration of oil. As most oil and gas has been in place for millions to tens of millions of years, depleted oil and gas reservoirs can contain carbon dioxide for millennia. Identified possible problems are the many 'leak' opportunities provided by old oil wells, the need for high injection pressures and acidification which can damage the geological barrier. Other disadvantages of old oil fields are their limited geographic distribution and depths, which require high injection pressures for sequestration. Below a depth of about 1000 m, carbon dioxide is injected as a supercritical fluid, a material with the density of a liquid, but the viscosity and diffusivity of a gas. Unmineable coal seams can be used to store CO2, because CO2 absorbs to the coal surface, ensuring safe long-term storage. In the process it releases methane that was previously adsorbed to the coal surface and that may be recovered. Again the sale of the methane can be used to offset the cost of the CO2 storage. Release or burning of methane would of course at least partially offset the obtained sequestration result – except when the gas is allowed to escape into the atmosphere in significant quantities: methane has a 80-fold higher global warming potential than CO2 (during the first twenty years).[96]

Saline aquifers contain highly mineralized brines and have so far been considered of no benefit to humans except in a few cases where they have been used for the storage of chemical waste. Their advantages include a large potential storage volume and relatively common occurrence reducing the distance over which CO2 has to be transported. The major disadvantage of saline aquifers is that relatively little is known about them compared to oil fields. Another disadvantage of saline aquifers is that as the salinity of the water increases, less CO2 can be dissolved into aqueous solution. To keep the cost of storage acceptable the geophysical exploration may be limited, resulting in larger uncertainty about the structure of a given aquifer. Unlike storage in oil fields or coal beds, no side product will offset the storage cost. Leakage of CO2 back into the atmosphere may be a problem in saline-aquifer storage. However, current research shows that several trapping mechanisms immobilize the CO2 underground, reducing the risk of leakage.[97]

A major research project examining the geological sequestration of carbon dioxide is currently being performed at an oil field at Weyburn in south-eastern Saskatchewan. In the North Sea, Norway's Equinor natural-gas platform Sleipner strips carbon dioxide out of the natural gas with amine solvents and disposes of this carbon dioxide by geological sequestration. Sleipner reduces emissions of carbon dioxide by approximately one million tonnes a year. The cost of geological sequestration is minor relative to the overall running costs. One of the first planned trial of large-scale sequestration of carbon dioxide stripped from power plant emissions in the Miller oilfield as its reserves are depleted by BP was not funded.[98]

In October 2007, the Bureau of Economic Geology at The University of Texas at Austin received a 10-year, $38 million subcontract to conduct the first intensively monitored, long-term project in the United States studying the feasibility of injecting a large volume of CO2 for underground storage.[99] The project is a research program of the , funded by the National Energy Technology Laboratory of the U.S. Department of Energy (DOE). The SECARB partnership will demonstrate CO2 injection rate and storage capacity in the Tuscaloosa-Woodbine geologic system that stretches from Texas to Florida. Beginning in fall 2007, the project will inject CO2 at the rate of one million tons[vague] per year, for up to 1.5 years, into brine up to 10,000 feet (3,000 m) below the land surface near the Cranfield oil field about 15 miles (24 km) east of Natchez, Mississippi. Experimental equipment will measure the ability of the subsurface to accept and retain CO2.[91]

Mineral sequestration

Mineral sequestration aims to trap carbon in the form of solid carbonate salts. This process occurs slowly in nature and is responsible for the deposition and accumulation of limestone over geologic time. Carbonic acid in groundwater slowly reacts with complex silicates to dissolve calcium, magnesium, alkalis and silica and leave a residue of clay minerals. The dissolved calcium and magnesium react with bicarbonate to precipitate calcium and magnesium carbonates, a process that organisms use to make shells. When the organisms die, their shells are deposited as sediment and eventually turn into limestone. Limestones have accumulated over billions of years of geologic time and contain much of Earth's carbon. Ongoing research aims to speed up similar reactions involving alkali carbonates.[100]

Several serpentinite deposits are being investigated as potentially large scale CO2 storage sinks such as those found in NSW, Australia, where the first mineral carbonation pilot plant project is underway.[101] Beneficial re-use of magnesium carbonate from this process could provide feedstock for new products developed for the built environment and agriculture without returning the carbon into the atmosphere and so acting as a carbon sink.[102]

One proposed reaction is that of the olivine-rich rock dunite, or its hydrated equivalent serpentinite with carbon dioxide to form the carbonate mineral magnesite, plus silica and iron oxide (magnetite).

Serpentinite sequestration is favored because of the non-toxic and stable nature of magnesium carbonate. The ideal reactions involve the magnesium endmember components of the olivine (reaction 1) or serpentine (reaction 2), the latter derived from earlier olivine by hydration and silicification (reaction 3). The presence of iron in the olivine or serpentine reduces the efficiency of sequestration, since the iron components of these minerals break down to iron oxide and silica (reaction 4).

Serpentinite reactions

Main article: Serpentinite
Mg-olivineMg2SiO4 + carbon dioxide2CO2 → magnesite 2MgCO3 + silica SiO2 + water H2O

 

 

 

 

(Reaction 1)

Serpentine Mg3[Si2O5(OH)4] + carbon dioxide3CO2 → magnesite 3MgCO3 + silica 2SiO2 + water 2H2O

 

 

 

 

(Reaction 2)

Mg-olivine3Mg2SiO4 + silica 2SiO2 + water 4H2O → serpentine 2Mg3[Si2O5(OH)4]

 

 

 

 

(Reaction 3)

Fe-olivine3Fe2SiO4 + water 2H2O → magnetite 2Fe3O4 + silica 3SiO2 + hydrogen 2H2

 

 

 

 

(Reaction 4)

[102]

Zeolitic imidazolate frameworks

Main article: Zeolitic imidazolate frameworks

Zeolitic imidazolate frameworks is a metal-organic framework carbon dioxide sink which could be used to keep industrial emissions of carbon dioxide out of the atmosphere.[103]

Trends in sink performance

 
Cumulative contributions to the global carbon budget since 1850 illustrate how source and sink components have been out of balance, causing a nearly 50% rise in atmospheric carbon dioxide concentration.[104]

One study in 2009 found that the fraction of fossil-fuel emissions absorbed by the oceans may have declined by up to 10% since 2000, indicating oceanic sequestration may be sublinear.[105] Another 2009 study found that the fraction of CO2 absorbed by terrestrial ecosystems and the oceans has not changed since 1850, indicating undiminished capacity.[106]

One study in 2020 found that 32 tracked Brazilian non-Amazon seasonal tropical forests declined from a carbon sink to a carbon source in 2013 and concludes that "policies are needed to mitigate the emission of greenhouse gases and to restore and protect tropical seasonal forests".[107][108]

The IPCC has noted that oceans and vegetation will progressively absorb a smaller fraction of CO2 emissions and, in return, create a larger absorption shortcoming.[109]

An emerging trend is the use of conservative or regenerative agriculture. According to Project Drawdown, regenerative agriculture could sink 9.43 to 13.4 gigatons of CO2 between 2020 and 2050. This will be a huge contribution to sink performance.[110]

See also

Sources

  This article incorporates text from a free content work. Licensed under CC BY-SA 3.0 IGO (license statement/permission). Text taken from Global Forest Resources Assessment 2020 Key findings, FAO, FAO. To learn how to add open license text to Wikipedia articles, please see this how-to page. For information on reusing text from Wikipedia, please see the terms of use.

References

  1. ^ a b "What is a carbon sink?". www.clientearth.org. Retrieved 18 June 2021.
  2. ^ "Carbon Sources and Sinks". National Geographic Society. 26 March 2020. from the original on 14 December 2020. Retrieved 18 June 2021.
  3. ^ "carbon sink — European Environment Agency". www.eea.europa.eu. Retrieved 18 June 2021.
  4. ^ Churkina, Galina; Organschi, Alan; Reyer, Christopher P. O.; Ruff, Andrew; Vinke, Kira; Liu, Zhu; Reck, Barbara K.; Graedel, T. E.; Schellnhuber, Hans Joachim (2020). "Buildings as a global carbon sink". Nature Sustainability. 3 (4): 269–276. doi:10.1038/s41893-019-0462-4. ISSN 2398-9629. S2CID 213032074.
  5. ^ "carbon sequestration | Definition, Methods, & Climate Change". Encyclopedia Britannica. Retrieved 18 June 2021.
  6. ^ Blakemore, R.J. (2018). "Non-Flat Earth Recalibrated for Terrain and Topsoil". Soil Systems. 2 (4): 64. doi:10.3390/soilsystems2040064.
  7. ^ "Carbon Sinks: A Brief Review". Earth.Org - Past | Present | Future. Retrieved 2 December 2020.
  8. ^ Environmental Protection Agency, United States (12 August 2013). "Overview of Greenhouse Gases". EPA Climate Change. US EPA. Retrieved 17 May 2015.
  9. ^ "STATE OF THE WORLD'S FORESTS 2001". www.fao.org. Retrieved 18 June 2021.
  10. ^ Karen Palmer; Dallas Burtraw. (PDF). Resources for the Future. Archived from the original (PDF) on 4 June 2007.
  11. ^ Manguiat MSZ, Verheyen R, Mackensen J, Scholz G (2005). (PDF). IUCN Environmental Policy and Law Papers. Number 59. Archived from the original (PDF) on 16 July 2010.
  12. ^ Rosenbaum KL, Schoene D, Mekouar A (2004). "Climate change and the forest sector. Possible national and subnational legislation". FAO Forestry Papers. Number 144.
  13. ^ Swift, Roger S. (November 2001). "Sequestration of Carbon by soil". Soil Science. 166 (11): 858–71. Bibcode:2001SoilS.166..858S. doi:10.1097/00010694-200111000-00010. S2CID 96820247.
  14. ^ Batjes, Niels H. (1996). "Total carbon and nitrogen in the soils of the world". European Journal of Soil Science. 47 (2): 151–63. doi:10.1111/j.1365-2389.1996.tb01386.x.
  15. ^ Batjes (2016). "Harmonised soil property values for broad-scale modelling (WISE30sec) with estimates of global soil carbon stocks". Geoderma. 269: 61–68. Bibcode:2016Geode.269...61B. doi:10.1016/j.geoderma.2016.01.034.
  16. ^ Klaus Lorenza; Rattan Lala; Caroline M. Prestonb; Klaas G.J. Nieropc (15 November 2007). "Strengthening the soil organic carbon pool by increasing contributions from recalcitrant aliphatic bio(macro)molecules". Geoderma. 142 (1–2): 1–10. Bibcode:2007Geode.142....1L. doi:10.1016/j.geoderma.2007.07.013.
  17. ^ "Coral Reefs Biome "Underwater Rainforests"". Retrieved 19 September 2021.
  18. ^ a b c "Organic Farming Can Cool the World that Chemical Farming Overheated". 17 October 2009. Retrieved 18 September 2021.
  19. ^ Woolf, Dominic; Amonette, James E.; Street-Perrott, F. Alayne; Lehmann, Johannes; Joseph, Stephen (10 August 2010). "Sustainable biochar to mitigate global climate change". Nature Communications. 1 (5): 56. Bibcode:2010NatCo...1...56W. doi:10.1038/ncomms1053. ISSN 2041-1723. PMC 2964457. PMID 20975722.
  20. ^ Mooney, Chris. "The really scary thing about wildfires is how they can worsen climate change". The Washington Post. Retrieved 24 January 2017.
  21. ^ "Deforestation & Carbon Emission". Consulting Geologist. Retrieved 24 January 2017.
  22. ^ Chester, Bronwyn (20 April 2000). "The case of the missing sink". McGill Reporter. Retrieved 17 June 2022.
  23. ^ Duncan Graham-Rowe (24 February 2005). . New Scientist. Archived from the original on 18 May 2008. Retrieved 8 July 2008.
  24. ^ C. Michael Hogan (28 December 2009). . In Cutler J. Cleveland (ed.). Encyclopedia of Earth. Sidney Draggan (Topic Editor). Washington DC: Environmental Information Coalition, National Council for Science and the Environment. Archived from the original on 11 July 2010.
  25. ^ Timothy J. LaSalle; Paul Hepperly (2008). (PDF) (Report). The Rodale Institute. Archived from the original (PDF) on 10 September 2008. Retrieved 19 May 2008.
  26. ^ "The Farming Systems Trial" (PDF). Rodale Institute. Archived from the original (PDF) on 22 February 2013. Retrieved 20 November 2013.
  27. ^ "Carbon Dioxide and Our Ocean Legacy, by Richard A. Feely et. al" (PDF). (PDF) from the original on 1 June 2006.
  28. ^ a b c Gao, Yang; Jia, Junjie; Lu, Yao; Sun, Kun; Wang, Jing; Wang, Shuoyue (2022). "Carbon transportation, transformation, and sedimentation processes at the land-river-estuary continuum". Fundamental Research. Elsevier BV. doi:10.1016/j.fmre.2022.07.007. ISSN 2667-3258. S2CID 251168582.   Modified material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
  29. ^ Schlünz, B.; Schneider, R. R. (22 March 2000). "Transport of terrestrial organic carbon to the oceans by rivers: re-estimating flux- and burial rates". International Journal of Earth Sciences. Springer Science and Business Media LLC. 88 (4): 599–606. Bibcode:2000IJEaS..88..599S. doi:10.1007/s005310050290. ISSN 1437-3254. S2CID 128411658.
  30. ^ Blair, Neal E.; Leithold, Elana L.; Aller, Robert C. (2004). "From bedrock to burial: The evolution of particulate organic carbon across coupled watershed-continental margin systems". Marine Chemistry. 92 (1–4): 141–156. doi:10.1016/j.marchem.2004.06.023.
  31. ^ Bouchez, Julien; Beyssac, Olivier; Galy, Valier; Gaillardet, Jérôme; France-Lanord, Christian; Maurice, Laurence; Moreira-Turcq, Patricia (2010). "Oxidation of petrogenic organic carbon in the Amazon floodplain as a source of atmospheric CO2". Geology. Geological Society of America. 38 (3): 255–258. Bibcode:2010Geo....38..255B. doi:10.1130/g30608.1. ISSN 1943-2682. S2CID 53512466.
  32. ^ Regnier, Pierre; Friedlingstein, Pierre; Ciais, Philippe; Mackenzie, Fred T.; et al. (9 June 2013). "Anthropogenic perturbation of the carbon fluxes from land to ocean" (PDF). Nature Geoscience. Springer Science and Business Media LLC. 6 (8): 597–607. Bibcode:2013NatGe...6..597R. doi:10.1038/ngeo1830. ISSN 1752-0894. S2CID 53418968.
  33. ^ a b Bauer, James E.; Cai, Wei-Jun; Raymond, Peter A.; Bianchi, Thomas S.; Hopkinson, Charles S.; Regnier, Pierre A. G. (4 December 2013). "The changing carbon cycle of the coastal ocean". Nature. Springer Science and Business Media LLC. 504 (7478): 61–70. Bibcode:2013Natur.504...61B. doi:10.1038/nature12857. ISSN 0028-0836. PMID 24305149. S2CID 4399374.
  34. ^ Cai, Wei-Jun (15 January 2011). "Estuarine and Coastal Ocean Carbon Paradox: CO2 Sinks or Sites of Terrestrial Carbon Incineration?". Annual Review of Marine Science. Annual Reviews. 3 (1): 123–145. Bibcode:2011ARMS....3..123C. doi:10.1146/annurev-marine-120709-142723. ISSN 1941-1405. PMID 21329201.
  35. ^ Galy, Valier; Peucker-Ehrenbrink, Bernhard; Eglinton, Timothy (2015). "Global carbon export from the terrestrial biosphere controlled by erosion". Nature. Springer Science and Business Media LLC. 521 (7551): 204–207. Bibcode:2015Natur.521..204G. doi:10.1038/nature14400. ISSN 0028-0836. PMID 25971513. S2CID 205243485.
  36. ^ Nellemann, Christian et al. (2009): Blue Carbon. The Role of Healthy Oceans in Binding Carbon. A Rapid Response Assessment. Arendal, Norway: UNEP/GRID-Arendal
  37. ^ a b Macreadie, P.I., Anton, A., Raven, J.A., Beaumont, N., Connolly, R.M., Friess, D.A., Kelleway, J.J., Kennedy, H., Kuwae, T., Lavery, P.S. and Lovelock, C.E. (2019) "The future of Blue Carbon science". Nature communications, 10(1): 1–13. doi:10.1038/s41467-019-11693-w.
  38. ^ Cathrine E., Lovelock; Duarte, Carlos M. (2019). "Dimensions of Blue Carbon and emerging perspectives". Biology Letters. 15 (3): 20180781. doi:10.1098/rsbl.2018.0781. PMC 6451379. PMID 30836882.
  39. ^ a b Ricart, Aurora M.; Krause-Jensen, Dorte; Hancke, Kasper; Price, Nichole N.; Masqué, Pere; Duarte, Carlos M. (2022). "Sinking seaweed in the deep ocean for carbon neutrality is ahead of science and beyond the ethics". Environmental Research Letters. 17 (8): 081003. Bibcode:2022ERL....17h1003R. doi:10.1088/1748-9326/ac82ff. S2CID 250973225.
  40. ^ Hurd, Catriona L.; Law, Cliff S.; Bach, Lennart T.; Britton, Damon; Hovenden, Mark; Paine, Ellie R.; Raven, John A.; Tamsitt, Veronica; Boyd, Philip W. (2022). "Forensic carbon accounting: Assessing the role of seaweeds for carbon sequestration". Journal of Phycology. 58 (3): 347–363. doi:10.1111/jpy.13249. PMID 35286717. S2CID 247453370.
  41. ^ Boyd, Philip W.; Bach, Lennart T.; Hurd, Catriona L.; Paine, Ellie; Raven, John A.; Tamsitt, Veronica (2022). "Potential negative effects of ocean afforestation on offshore ecosystems". Nature Ecology & Evolution. 6 (6): 675–683. doi:10.1038/s41559-022-01722-1. PMID 35449458. S2CID 248322820.
  42. ^ Carolyn Gramling (28 September 2017). "Tropical forests have flipped from sponges to sources of carbon dioxide; A closer look at the world's trees reveals a loss of density in the tropics". Sciencenews.org. 358 (6360): 230–234. Bibcode:2017Sci...358..230B. doi:10.1126/science.aam5962. PMID 28971966. Retrieved 6 October 2017.
  43. ^ Baccini A, Walker W, Carvalho L, Farina M, Sulla-Menashe D, Houghton RA (13 October 2017). "Tropical forests are a net carbon source based on aboveground measurements of gain and loss". Science. 358 (6360): 230–234. Bibcode:2017Sci...358..230B. doi:10.1126/science.aam5962. PMID 28971966.
  44. ^ Spawn, Seth A.; Sullivan, Clare C.; Lark, Tyler J.; Gibbs, Holly K. (December 2020). "Harmonized global maps of above and belowground biomass carbon density in the year 2010". Scientific Data. 7 (1): 112. Bibcode:2020NatSD...7..112S. doi:10.1038/s41597-020-0444-4. PMC 7136222. PMID 32249772.
  45. ^ a b "Does harvesting in Canada's forests contribute to climate change?" (PDF). Canadian Forest Service Science-Policy Notes. Natural Resources Canada. May 2007. (PDF) from the original on 30 July 2013.[permanent dead link]
  46. ^ Global Forest Resources Assessment 2020 – Key findings. Rome: FAO. 2020. doi:10.4060/ca8753en. ISBN 978-92-5-132581-0. S2CID 130116768.
  47. ^ Global Forest Resources Assessment 2020 – Key findings. FAO. 2020. doi:10.4060/ca8753en. ISBN 978-92-5-132581-0. S2CID 130116768.
  48. ^ Chen, JM; Ciais, Philippe (18 September 2019). "Vegetation structural change since 1981 significantly enhanced the terrestrial carbon sink". Nature Communications. 10 (4259): 4259. Bibcode:2019NatCo..10.4259C. doi:10.1038/s41467-019-12257-8. PMC 6751163. PMID 31534135.
  49. ^ Harvey, Fiona (4 March 2020). "Tropical forests losing their ability to absorb carbon, study finds". The Guardian. ISSN 0261-3077. Retrieved 5 March 2020.
  50. ^ Jonathan Amos (15 December 2006). "Care needed with carbon offsets". BBC. Retrieved 8 July 2008.
  51. ^ . Lawrence Livermore National Laboratory. 5 December 2005. Archived from the original on 27 May 2010. Retrieved 8 July 2008.
  52. ^ S. Gibbard; K. Caldeira; G. Bala; T. J. Phillips; M. Wickett (December 2005). "Climate effects of global land cover change". Geophysical Research Letters. 32 (23): L23705. Bibcode:2005GeoRL..3223705G. doi:10.1029/2005GL024550.
  53. ^ Malhi, Yadvinder; Meir, Patrick; Brown, Sandra (2002). "Forests, carbon and global climate". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 360 (1797): 1567–91. Bibcode:2002RSPTA.360.1567M. doi:10.1098/rsta.2002.1020. PMID 12460485. S2CID 1864078.
  54. ^ . EPA. Archived from the original on 1 June 2010. Retrieved 8 July 2008.
  55. ^ a b c d (PDF). EPA. Archived from the original (PDF) on 23 May 2008. Retrieved 8 July 2008.
  56. ^ a b (PDF). EPA. Archived from the original (PDF) on 18 July 2008. Retrieved 8 July 2008.
  57. ^ William H. Schlesinger, dean of the Nicholas School of the Environment and Earth Sciences at Duke University, in Durham, North Carolina.
  58. ^ "This Is The Impact Of 1 Million Trees". 26 November 2019. Retrieved 18 September 2021.
  59. ^ Grant M. Domke; Sonja N. Oswalt; Brian F. Walters; Randall S. Morin (6 October 2020). "Tree planting has the potential to increase carbon sequestration capacity of forests in the United States" (PDF). PNAS. 117 (40): 24649–24651. Bibcode:2020PNAS..11724649D. doi:10.1073/pnas.2010840117. PMC 7547226. PMID 32958649. S2CID 221842058. (PDF) from the original on 20 October 2020.
  60. ^ (PDF). International Panel on Climate Change. p. 549. Archived from the original (PDF) on 4 August 2009. Retrieved 11 August 2009.
  61. ^ Ruddell, Steven; et al. (September 2007). "The Role for Sustainably Managed Forests in Climate Change Mitigation". Journal of Forestry. 105 (6): 314–319.
  62. ^ J. Chatellier (January 2010). (PDF). Yale School of Forestry and Environmental Studies. Archived from the original (PDF) on 5 July 2010.
  63. ^ Harmon, M. E.; Harmon, J. M.; Ferrell, W. K.; Brooks, D. (1996). "Modeling carbon stores in Oregon and Washington forest products: 1900?1992". Climatic Change. 33 (4): 521. Bibcode:1996ClCh...33..521H. doi:10.1007/BF00141703. S2CID 27637103.
  64. ^ a b David E. Steitz; Krishna Ramanujan; Kent LaBorde (2003). "Ocean Plant Life Slows Down And Absorbs Less Carbon".
  65. ^ Quirin Schiermeier (22 April 2004). "Iron seeding creates fleeting carbon sink in Southern Ocean". Nature. 428 (6985): 788. Bibcode:2004Natur.428..788S. doi:10.1038/428788b. PMID 15103342. S2CID 33727485.
  66. ^ Roelofs, G. (2008). "A GCM study of organic matter in marine aerosol and its potential contribution to cloud drop activation". Atmospheric Chemistry and Physics. 8 (3): 709–719. Bibcode:2008ACP.....8..709R. doi:10.5194/acp-8-709-2008. hdl:2066/34516.
  67. ^ Michael Markels Jr; Richard T. Barber (14–17 May 2001). (PDF). NETL Conference on Carbon Sequestration. Archived from the original (PDF) on 10 September 2008. Retrieved 8 July 2008.
  68. ^ . GreenSea Venture. Archived from the original on 15 April 2008. Retrieved 8 July 2008.
  69. ^ Mitrovic, Simon M.; Fernández Amandi, Monica; McKenzie, Lincoln; Furey, Ambrose; James, Kevin J. (2004). "Effects of selenium, iron and cobalt addition to growth and yessotoxin production of the toxic marine dinoflagellate Protoceratium reticulatum in culture". Journal of Experimental Marine Biology and Ecology. 313 (2): 337–51. doi:10.1016/j.jembe.2004.08.014.
  70. ^ "Visualizing Carbon Storage in Earth's Ecosystems". 25 January 2022. Retrieved 31 January 2022.
  71. ^ Susan S. Lang (13 July 2005). "Organic farming produces same corn and soybean yields as conventional farms, but consumes less energy and no pesticides, study finds". Retrieved 8 July 2008.
  72. ^ Pimentel, David; Hepperly, Paul; Hanson, James; Douds, David; Seidel, Rita (2005). "Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems". BioScience. 55 (7): 573–82. doi:10.1641/0006-3568(2005)055[0573:EEAECO]2.0.CO;2.
  73. ^ Lal, Rattan; Griffin, Michael; Apt, Jay; Lave, Lester; Morgan, M. Granger (2004). "Ecology: Managing Soil Carbon". Science. 304 (5669): 393. doi:10.1126/science.1093079. PMID 15087532. S2CID 129925989.
  74. ^ Johannes Lehmann. . Archived from the original on 18 June 2008. Retrieved 8 July 2008.
  75. ^ Horstman, Mark (23 September 2007). "Agrichar – A solution to global warming?". ABC TV Science: Catalyst. Australian Broadcasting Corporation. Retrieved 8 July 2008.
  76. ^ Monique Brouillette (17 March 2021). "How microbes in permafrost could trigger a massive carbon bomb". Nature. 591 (7850): 360–362. Bibcode:2021Natur.591..360B. doi:10.1038/d41586-021-00659-y. PMID 33731951. S2CID 232297719.
  77. ^ "One Russian scientist hopes to slow the thawing of the Arctic". The Economist. 16 December 2020.
  78. ^ . Savanna Information. Tropical Savannas Cooperative Research Centre. Archived from the original on 3 July 2008. Retrieved 8 July 2008.
  79. ^ . Savanna Information. Tropical Savannas Cooperative Research Centre. Archived from the original on 3 July 2008. Retrieved 8 July 2008.
  80. ^ Ning Zeng (2008). "Carbon sequestration via wood burial". Carbon Balance and Management. 3: 1. doi:10.1186/1750-0680-3-1. PMC 2266747. PMID 18173850.
  81. ^ "Climate Change, Global Warming, and the Built Environment – Architecture 2030". Retrieved 23 February 2007.
  82. ^ "Processing Natural Gas". NaturalGas.org. Retrieved 9 February 2018.
  83. ^ Churkina, Galina; Organschi, Alan; Reyer, Christopher P. O.; Ruff, Andrew; Vinke, Kira; Liu, Zhu; Reck, Barbara K.; Graedel, T. E.; Schellnhuber, Hans Joachim (April 2020). "Buildings as a global carbon sink". Nature Sustainability. 3 (4): 269–276. doi:10.1038/s41893-019-0462-4. S2CID 213032074. Retrieved 20 June 2020.
  84. ^ Keith, David W.; Holmes, Geoffrey; St. Angelo, David; Heide, Kenton (7 June 2018). "A Process for Capturing CO2 from the Atmosphere". Joule. 2 (8): 1573–1594. doi:10.1016/j.joule.2018.05.006.
  85. ^ Beuttler, Christoph; Charles, Louise; Wurzbacher, Jan (21 November 2019). "The Role of Direct Air Capture in Mitigation of Anthropogenic Greenhouse Gas Emissions". Frontiers in Climate. 1: 10. doi:10.3389/fclim.2019.00010.
  86. ^ Sanz-Pérez, Eloy S.; Murdock, Christopher R.; Didas, Stephanie A.; Jones, Christopher W. (12 October 2016). "Direct Capture of carbon dioxide from Ambient Air". Chemical Reviews. 116 (19): 11840–11876. doi:10.1021/acs.chemrev.6b00173. PMID 27560307.
  87. ^ "Direct Air Capture (Technology Factsheet)" (PDF). Geoengineering Monitor. 24 May 2018. (PDF) from the original on 26 August 2019. Retrieved 27 August 2019.
  88. ^ Erans, María; Sanz-Pérez, Eloy S.; Hanak, Dawid P.; Clulow, Zeynep; Reiner, David M.; Mutch, Greg A. (2022). "Direct air capture: process technology, techno-economic and socio-political challenges". Energy & Environmental Science. 15 (4): 1360–1405. doi:10.1039/D1EE03523A. ISSN 1754-5692.
  89. ^ Erans, María; Sanz-Pérez, Eloy S.; Hanak, Dawid P.; Clulow, Zeynep; Reiner, David M.; Mutch, Greg A. (2022). "Direct air capture: process technology, techno-economic and socio-political challenges". Energy & Environmental Science. 15 (4): 1360–1405. doi:10.1039/D1EE03523A. ISSN 1754-5692.
  90. ^ Quarton, Christopher J.; Samsatli, Sheila (1 January 2020). "The value of hydrogen and carbon capture, storage and utilisation in decarbonising energy: Insights from integrated value chain optimisation". Applied Energy. 257: 113936. doi:10.1016/j.apenergy.2019.113936. S2CID 208829001.
  91. ^ a b Brewer, Peter G.; Peltzer, Edward T.; Orr, Franklin M. Jr. (7 May 1999). "Direct Experiments on the Ocean Disposal of Fossil Fuel CO2". Science. 284 (5416): 943–945. Bibcode:1999Sci...284..943B. doi:10.1126/science.284.5416.943. PMID 10320370.
  92. ^ The Christian Science Monitor (28 April 2008). "Potent greenhouse-gas methane has been rising". The Christian Science Monitor.
  93. ^ Norman Baker; Ben Bradshaw (4 July 2005). "Carbon Sequestration". Retrieved 8 July 2008.
  94. ^ Zakem, Emily J.; Mahadevan, Amala; Lauderdale, Jonathan M.; Follows, Michael J. (2020). "Stable aerobic and anaerobic coexistence in anoxic marine zones". The ISME Journal. 14 (1): 288–301. doi:10.1038/s41396-019-0523-8. PMC 6908664. PMID 31624350. S2CID 204758450.
  95. ^ "Sequestration of Supercritical CO2 in Deep Sedimentary Geological Formations". Negative Emissions Technologies and Reliable Sequestration: A Research Agenda (Report). Washington, DC: The National Academies Press. 2019. pp. 319–350. doi:10.17226/25259. ISBN 978-0-309-48452-7.
  96. ^ "Methane: A crucial opportunity in the climate fight (Environmental Defense Fund)". Retrieved 18 September 2021.
  97. ^ Stephanie Flude, Juan Alcade (4 March 2020). "Carbon capture and storage has stalled needlessly".
  98. ^ "CO2 storage in depleted oilfields" (PDF). 2009. (PDF) from the original on 1 October 2015.
  99. ^ . Jackson School of Geosciences, The University of Texas at Austin. 24 October 2007. Archived from the original on 11 June 2010. Retrieved 14 April 2010.
  100. ^ "Carbon-capture Technology To Help UK Tackle Global Warming". ScienceDaily. 27 July 2007.
  101. ^ "Mineral carbonation project for NSW". 9 June 2010.
  102. ^ a b Frost, B. R.; Beard, J. S. (3 April 2007). "On Silica Activity and Serpentinization". Journal of Petrology. 48 (7): 1351–1368. doi:10.1093/petrology/egm021.
  103. ^ "New materials can selectively capture CO2, scientists say". CBC News. 15 February 2008.
  104. ^ "Global Carbon Budget 2021" (PDF). Global Carbon Project. 4 November 2021. p. 57. (PDF) from the original on 11 December 2021. The cumulative contributions to the global carbon budget from 1850. The carbon imbalance represents the gap in our current understanding of sources & sinks. ... Source: Friedlingstein et al 2021; Global Carbon Project 2021
  105. ^ Earth Institute News, Columbia University, 18 November 2009
  106. ^ Knorr, W. (2009). "Is the airborne fraction of anthropogenic CO2 emissions increasing?". Geophysical Research Letters. 36 (21): L21710. Bibcode:2009GeoRL..3621710K. doi:10.1029/2009GL040613.
    • "Controversial new climate change results". University of Bristol (Press release). 9 November 2009.
  107. ^ "Brazilian forests found to be transitioning from carbon sinks to carbon sources". phys.org. Retrieved 16 January 2021.
  108. ^ Maia, Vinícius Andrade; Santos, Alisson Borges Miranda; Aguiar-Campos, Natália de; Souza, Cléber Rodrigo de; Oliveira, Matheus Coutinho Freitas de; Coelho, Polyanne Aparecida; Morel, Jean Daniel; Costa, Lauana Silva da; Farrapo, Camila Laís; Fagundes, Nathalle Cristine Alencar; Paula, Gabriela Gomes Pires de; Santos, Paola Ferreira; Gianasi, Fernanda Moreira; Silva, Wilder Bento da; Oliveira, Fernanda de; Girardelli, Diego Teixeira; Araújo, Felipe de Carvalho; Vilela, Taynara Andrade; Pereira, Rafaella Tavares; Silva, Lidiany Carolina Arantes da; Menino, Gisele Cristina de Oliveira; Garcia, Paulo Oswaldo; Fontes, Marco Aurélio Leite; Santos, Rubens Manoel dos (1 December 2020). "The carbon sink of tropical seasonal forests in southeastern Brazil can be under threat". Science Advances. 6 (51): eabd4548. Bibcode:2020SciA....6.4548M. doi:10.1126/sciadv.abd4548. ISSN 2375-2548. PMID 33355136.
  109. ^ Kirn, Marda (2016). Climate Literacy: From the "What" of Climate Change to the "So What" of Personal and Social Change. Geological Society of America Annual Meeting in Denver, Colorado, USA (Abstract). Geological Society of America. doi:10.1130/abs/2016am-287348.
  110. ^ Schleien, Danny (24 September 2020). "We Need To Harness Natural Carbon Sinks To Reverse Climate Change". Climate Conscious. Retrieved 11 November 2021.

External links

  • Carbon Capture and Sequestration Technologies Program at MIT

January 31, 2023
carbon, sink, carbon, sink, anything, natural, otherwise, that, accumulates, stores, some, carbon, containing, chemical, compound, indefinite, period, thereby, removes, carbon, dioxide, from, atmosphere, this, diagram, fast, carbon, cycle, shows, movement, car. A carbon sink is anything natural or otherwise that accumulates and stores some carbon containing chemical compound for an indefinite period and thereby removes carbon dioxide CO2 from the atmosphere 1 This diagram of the fast carbon cycle shows the movement of carbon between land atmosphere soil and oceans in billions of tons of carbon per year Yellow numbers are natural fluxes red are human contributions in billions of tons of carbon per year White numbers indicate stored carbon Globally the two most important carbon sinks are vegetation and the ocean 2 Public awareness of the significance of CO2 sinks has grown since passage of the 1997 Kyoto Protocol which promotes their use as a form of carbon offset 3 There are also different strategies used to enhance this process Soil is an important carbon storage medium Much of the organic carbon retained in the soil of agricultural areas has been depleted due to intensive farming Blue carbon designates carbon that is fixed via the ocean ecosystems Mangroves salt marshes and seagrasses make up a majority of ocean plant life and store large quantities of carbon Many efforts are being made to enhance natural sequestration in soils and the oceans 1 In addition a range of artificial sequestration initiatives are underway such as changed building construction materials carbon capture and storage and geological sequestration 4 5 Contents 1 General 2 Kyoto Protocol 3 Storage in terrestrial and marine environments 3 1 Soils 3 2 Regenerative agriculture 3 3 Riverine transport 3 4 Oceans 4 Enhancing natural sequestration 4 1 Forests 4 2 Oceans 4 3 Soils 4 4 Savanna 5 Artificial sequestration 5 1 Buildings 5 2 Direct air capture 5 3 Oceans 5 4 Geological sequestration 5 5 Mineral sequestration 5 5 1 Serpentinite reactions 5 5 2 Zeolitic imidazolate frameworks 6 Trends in sink performance 7 See also 8 Sources 9 References 10 External linksGeneral Edit Air sea exchange of CO2 Increase in atmospheric carbon dioxide means increase in global temperature The amount of carbon dioxide varies naturally in a dynamic equilibrium with photosynthesis of land plants The natural sinks are Soil is a carbon store and active carbon sink 6 Photosynthesis by terrestrial plants with grass and trees allows them to serve as carbon sinks during growing seasons Absorption of carbon dioxide by the oceans via solubility and biological pumpsWhile the creation of artificial sinks has been discussed no major artificial systems remove carbon from the atmosphere on a material scale yet 7 Carbon sources include the combustion of fossil fuels coal natural gas and oil by humans for energy and transportation 8 Kyoto Protocol EditThe Kyoto Protocol was an international agreement that aimed at reducing carbon dioxide CO2 emissions and the presence of greenhouse gases GHG in the atmosphere The essential tenet of the Kyoto Protocol was that industrialized nations needed to reduce their CO2 emissions Because growing vegetation takes in carbon dioxide the Kyoto Protocol allows Annex I countries with large areas of growing forests to issue Removal Units to recognize the sequestration of carbon The additional units make it easier for them to achieve their target emission levels It is estimated that forests absorb between 10 to 20 tonnes per hectare 4 0 to 8 0 long ton acre 4 5 to 8 9 short ton acre each year through photosynthetic conversion into starch cellulose lignin and other components of wooden biomass While this has been well documented for temperate forests and plantations the fauna of the tropical forests place some limitations for such global estimates 9 Some countries seek to trade emission rights in carbon emission markets purchasing the unused carbon emission allowances of other countries If overall limits on greenhouse gas emission are put into place cap and trade market mechanisms are purported to find cost effective ways to reduce emissions 10 There is as yet no carbon audit regime for all such markets globally and none is specified in the Kyoto Protocol National carbon emissions are self declared In the Clean Development Mechanism only afforestation and reforestation are eligible to produce certified emission reductions CERs in the first commitment period of the Kyoto Protocol 2008 2012 Forest conservation activities or activities avoiding deforestation which would result in emission reduction through the conservation of existing carbon stocks are not eligible at this time 11 Also agricultural carbon sequestration is not possible yet 12 Storage in terrestrial and marine environments EditSoils Edit This section needs to be updated The reason given is IPCC Climate Change and Land report Please help update this article to reflect recent events or newly available information November 2019 Soils represent a short to long term carbon storage medium and contain more carbon than all terrestrial vegetation and the atmosphere combined 13 14 15 Plant litter and other biomass including charcoal accumulates as organic matter in soils and is degraded by chemical weathering and biological degradation More recalcitrant organic carbon polymers such as cellulose hemi cellulose lignin aliphatic compounds waxes and terpenoids are collectively retained as humus 16 Organic matter tends to accumulate in litter and soils of colder regions such as the boreal forests of North America and the Taiga of Russia Leaf litter and humus are rapidly oxidized and poorly retained in sub tropical and tropical climate conditions due to high temperatures and extensive leaching by rainfall Areas where shifting cultivation or slash and burn agriculture are practiced are generally only fertile for two to three years before they are abandoned These tropical jungles are similar to coral reefs in that they are highly efficient at conserving and circulating necessary nutrients which explains their lushness in a nutrient desert 17 Much organic carbon retained in many agricultural areas worldwide has been severely depleted due to intensive farming practices 18 Grasslands contribute to soil organic matter stored mainly in their extensive fibrous root mats Due in part to the climatic conditions of these regions e g cooler temperatures and semi arid to arid conditions these soils can accumulate significant quantities of organic matter This can vary based on rainfall the length of the winter season and the frequency of naturally occurring lightning induced grass fires While these fires release carbon dioxide they improve the quality of the grasslands overall in turn increasing the amount of carbon retained in the humic material They also deposit carbon directly to the soil in the form of Biochar that does not significantly degrade back to carbon dioxide 19 Forest fires release absorbed carbon back into the atmosphere 20 as does deforestation due to rapidly increased oxidation of soil organic matter 21 Organic matter in peat bogs undergoes slow anaerobic decomposition below the surface This process is slow enough that in many cases the bog grows rapidly and fixes more carbon from the atmosphere than is released Over time the peat grows deeper Peat bogs hold approximately one quarter of the carbon stored in land plants and soils 22 Under some conditions forests and peat bogs may become sources of CO2 such as when a forest is flooded by the construction of a hydroelectric dam Unless the forests and peat are harvested before flooding the rotting vegetation is a source of CO2 and methane comparable in magnitude to the amount of carbon released by a fossil fuel powered plant of equivalent power 23 Regenerative agriculture Edit See also Biosequestration Current agricultural practices lead to carbon loss from soils It has been suggested that improved farming practices could improve the capacity of the soil carbon sponge to hold carbon and water Present worldwide practises of overgrazing are substantially reducing many grasslands performance as soil carbon sponges 24 The Rodale Institute says that regenerative agriculture if practiced on the planet s tillable land of 15 million km2 3 6 billion acres could sequester up to 40 of current CO2 emissions 25 They claim that agricultural carbon sequestration has the potential to mitigate global warming When using biologically based regenerative practices this dramatic benefit can be accomplished with no decrease in yields or farmer profits 26 Organically managed soils can convert carbon dioxide from a greenhouse gas into a food producing asset 18 In 2006 U S carbon dioxide emissions largely from fossil fuel combustion were estimated at nearly 5 9 billion tonnes 6 5 billion short tons 27 If a 220 tonnes per square kilometre 2 000 lb acre per year sequestration rate was achieved on all 1 76 million km2 434 million acres of cropland in the United States nearly 1 5 billion t 1 6 billion short tons of carbon dioxide would be sequestered per year mitigating close to one quarter of the country s total fossil fuel emissions 18 Riverine transport Edit How carbon moves from inland waters to the ocean Carbon dioxide exchange photosynthetic production and respiration of terrestrial vegetation rock weathering and sedimentation occur in terrestrial ecosystems Carbon transports to the ocean through the land river estuary continuum in the form of organic carbon and inorganic carbon Carbon exchange at the air water interface transportation transformation and sedimentation occur in oceanic ecosystems 28 Terrestrial and marine ecosystems are chiefly connected through riverine transport which acts as the main channel through which erosive terrestrially derived substances enter into oceanic systems Material and energy exchanges between the terrestrial biosphere and the lithosphere as well as organic carbon fixation and oxidation processes together regulate ecosystem carbon and dioxygen O2 pools 28 Riverine transport being the main connective channel of these pools will act to transport net primary productivity primarily in the form of dissolved organic carbon DOC and particulate organic carbon POC from terrestrial to oceanic systems 29 During transport part of DOC will rapidly return to the atmosphere through redox reactions causing carbon degassing to occur between land atmosphere storage layers 30 31 The remaining DOC and dissolved inorganic carbon DIC are also exported to the ocean 32 33 34 Currently 2015 inorganic and organic carbon export fluxes from global rivers to the ocean amount to 0 50 0 70 Pg C y 1 and 0 15 0 35 Pg C y 1 respectively 33 On the other hand POC can remain buried in sediment over an extensive period and the annual global terrestrial to oceanic POC flux has been estimated at 0 20 0 13 0 07 Gg C y 1 35 28 Oceans Edit This section is an excerpt from Blue carbon edit Estimates of the economic value of blue carbon ecosystems per hectare Based on 2009 data from UNEP GRID Arendal 36 37 Blue carbon refers to organic carbon that is captured and stored by the world s oceanic and coastal ecosystems mostly by algae seagrasses macroalgae mangroves salt marshes and other plants in coastal wetlands 37 The term blue carbon was coined in 2009 to highlight the contribution of coastal vegetated ecosystems to climate change mitigation 38 Because oceans cover 70 of the planet there is increasing industry interest in developing blue carbon potential 39 Research is ongoing and while in some cases it has been found that these types of ecosystems remove far more carbon per area than terrestrial forests the effectiveness of blue carbon as a carbon dioxide removal solution remains highly contested 40 39 41 Enhancing natural sequestration EditForests Edit See also Biosequestration Forests can be carbon stores 42 43 44 and they are carbon dioxide sinks when they are increasing in density or area In Canada s boreal forests as much as 80 of the total carbon is stored in the soils as dead organic matter 45 A 40 year study of African Asian and South American tropical forests by the University of Leeds showed that tropical forests absorb about 18 of all carbon dioxide added by fossil fuels For the last three decades the amount of carbon absorbed by the world s intact tropical forests has fallen according to a study published in 2020 in the journal Nature Proportion of carbon stock in forest carbon pools 2020 46 The total carbon stock in forests decreased from 668 gigatonnes in 1990 to 662 gigatonnes in 2020 47 However another study finds that the leaf area index has increased globally since 1981 which was responsible for 12 4 of the accumulated terrestrial carbon sink from 1981 to 2016 The CO2 fertilization effect on the other hand was responsible for 47 of the sink while climate change reduced the sink by 28 6 48 In 2019 they took up a third less carbon than they did in the 1990s due to higher temperatures droughts and deforestation The typical tropical forest may become a carbon source by the 2060s 49 Truly mature tropical forests by definition grow rapidly with each tree producing at least 10 new trees each year Based on studies by FAO and UNEP it has been estimated that Asian forests absorb about 5 tonnes of carbon dioxide per hectare each year The global cooling effect of carbon sequestration by forests is partially counterbalanced in that reforestation can decrease the reflection of sunlight albedo Mid to high latitude forests have a much lower albedo during snow seasons than flat ground thus contributing to warming Modeling that compares the effects of albedo differences between forests and grasslands suggests that expanding the land area of forests in temperate zones offers only a temporary cooling benefit 50 51 52 53 In the United States in 2004 the most recent year for which EPA statistics 54 are available forests sequestered 10 6 637 megatonnes 55 of the carbon dioxide released in the United States by the combustion of fossil fuels coal oil and natural gas 5 657 megatonnes 56 Urban trees sequestered another 1 5 88 megatonnes 55 To further reduce U S carbon dioxide emissions by 7 as stipulated by the Kyoto Protocol would require the planting of an area the size of Texas 8 of the area of Brazil every 30 years 57 Carbon offset programs are planting millions of fast growing trees per year to reforest tropical lands for as little as 0 10 per tree over their typical 40 year lifetime one million of these trees will fix 1 a million tons of carbon dioxide 58 59 In Canada reducing timber harvesting would have very little impact on carbon dioxide emissions because of the combination of harvest and stored carbon in manufactured wood products along with the regrowth of the harvested forests Additionally the amount of carbon released from harvesting is small compared to the amount of carbon lost each year to forest fires and other natural disturbances 45 The Intergovernmental Panel on Climate Change concluded that a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks while producing an annual sustained yield of timber fibre or energy from the forest will generate the largest sustained mitigation benefit 60 Sustainable management practices keep forests growing at a higher rate over a potentially longer period of time thus providing net sequestration benefits in addition to those of unmanaged forests 61 Life expectancy of forests varies throughout the world influenced by tree species site conditions and natural disturbance patterns In some forests carbon may be stored for centuries while in other forests carbon is released with frequent stand replacing fires Forests that are harvested prior to stand replacing events allow for the retention of carbon in manufactured forest products such as lumber 62 However only a portion of the carbon removed from logged forests ends up as durable goods and buildings The remainder ends up as sawmill by products such as pulp paper and pallets which often end with incineration resulting in carbon release into the atmosphere at the end of their lifecycle For instance of the 1 692 megatonnes of carbon harvested from forests in Oregon and Washington from 1900 to 1992 only 23 is in long term storage in forest products 63 Oceans Edit See also Iron fertilization Enhanced weathering and Ocean nourishment One way to increase the carbon sequestration efficiency of the oceans is to add micrometre sized iron particles in the form of either hematite iron oxide or melanterite iron sulfate to certain regions of the ocean This has the effect of stimulating growth of plankton Iron is an important nutrient for phytoplankton usually made available via upwelling along the continental shelves inflows from rivers and streams as well as deposition of dust suspended in the atmosphere Natural sources of ocean iron have been declining in recent decades contributing to an overall decline in ocean productivity 64 Yet in the presence of iron nutrients plankton populations quickly grow or bloom expanding the base of biomass productivity throughout the region and removing significant quantities of CO2 from the atmosphere via photosynthesis A test in 2002 in the Southern Ocean around Antarctica suggests that between 10 000 and 100 000 carbon atoms are sunk for each iron atom added to the water 65 Application of iron nutrients in select parts of the oceans at appropriate scales could have the combined effect of restoring ocean productivity while at the same time mitigating the effects of human caused emissions of carbon dioxide to the atmosphere 64 Because the effect of periodic small scale phytoplankton blooms on ocean ecosystems is unclear more studies would be helpful Phytoplankton have a complex effect on cloud formation via the release of substances such as dimethyl sulfide DMS that are converted to sulfate aerosols in the atmosphere providing cloud condensation nuclei or CCN 66 Other nutrients such as nitrates phosphates and silica as well as iron may cause ocean fertilization There has been some speculation that using pulses of fertilization around 20 days in length may be more effective at getting carbon to ocean floor than sustained fertilization 67 There is some controversy over seeding the oceans with iron however due to the potential for increased toxic phytoplankton growth e g red tide declining water quality due to overgrowth and increasing anoxia in areas harming other sea life such as zooplankton fish coral etc 68 69 Soils Edit Since the 1850s a large proportion of the world s grasslands have been tilled and converted to croplands allowing the rapid oxidation of large quantities of soil organic carbon However in the United States in 2004 the most recent year for which EPA statistics are available agricultural soils including pasture land sequestered 0 8 46 megatonne 55 as much carbon as was released in the United States by the combustion of fossil fuels 5 988 megatonne 56 The annual amount of this sequestration has been gradually increasing since 1998 70 55 Methods that significantly enhance carbon sequestration in soil include no till farming residue mulching cover cropping and crop rotation all of which are more widely used in organic farming than in conventional farming 71 72 Because only 5 of US farmland currently uses no till and residue mulching there is a large potential for carbon sequestration 73 Conversion to pastureland particularly with good management of grazing can sequester even more carbon in the soil Terra preta an anthropogenic high carbon soil is also being investigated as a sequestration mechanism By pyrolysing biomass about half of its carbon can be reduced to charcoal which can persist in the soil for centuries and makes a useful soil amendment especially in tropical soils biochar or agrichar 74 75 For most of human history permafrost has been Earth s largest terrestrial carbon sink trapping plant and animal material in its frozen layers for centuries It currently stores about 1 600 billion tonnes of carbon more than twice the amount in the atmosphere today But thanks to rising temperatures permafrost is fracturing and disappearing 76 Sergey Zimov has proposed to restore and protect this major carbon sequestration mechanism via restoration of grassland and large arctic mammalian herbivores 77 Savanna Edit Controlled burns on far north Australian savannas can result in an overall carbon sink One working example is the West Arnhem Fire Management Agreement started to bring strategic fire management across 28 000 km2 of Western Arnhem Land Deliberately starting controlled burns early in the dry season results in a mosaic of burnt and unburnt country which reduces the area of burning compared with stronger late dry season fires In the early dry season there are higher moisture levels cooler temperatures and lighter wind than later in the dry season fires tend to go out overnight Early controlled burns also results in a smaller proportion of the grass and tree biomass being burnt 78 Emission reductions of 256 000 tonnes of CO2 have been made as of 2007 79 Artificial sequestration EditFor carbon to be sequestered artificially i e not using the natural processes of the carbon cycle it must first be captured or it must be significantly delayed or prevented from being re released into the atmosphere by combustion decay etc from an existing carbon rich material by being incorporated into an enduring usage such as in construction Thereafter it can be passively stored or remain productively utilized over time in a variety of ways For instance upon harvesting wood as a carbon rich material can be immediately burned or otherwise serve as a fuel returning its carbon to the atmosphere or it can be incorporated into construction or a range of other durable products thus sequestering its carbon over years or even centuries 80 A very carefully designed and durable energy efficient and energy capturing building has the potential to sequester in its carbon rich construction materials as much as or more carbon than was released by the acquisition and incorporation of all its materials and than will be released by building function energy imports during the structure s potentially multi century existence Such a structure might be termed carbon neutral or even carbon negative Building construction and operation electricity usage heating etc are estimated to contribute nearly half of the annual human caused carbon additions to the atmosphere 81 Natural gas purification plants often already have to remove carbon dioxide either to avoid dry ice clogging gas tankers or to prevent carbon dioxide concentrations exceeding the 3 maximum permitted on the natural gas distribution grid 82 Buildings Edit Mjostarnet one of the tallest timber buildings at its opening 2019 According to an international team of interdisciplinary scientists in a 2020 study broad base adoption of mass timber and their substitution for steel and concrete in new mid rise construction projects over the next few decades has the potential to turn timber buildings into a global carbon sink as they store the carbon dioxide taken up from the air by trees that are harvested and used as mass timber Noting the demographic need for new urban construction for the next thirty years the team analyzed four scenarios for the transition to mass timber new mid rise construction Assuming business as usual only 0 5 of new buildings worldwide would be constructed with timber by 2050 scenario 1 This could be driven up to 10 scenario 2 or 50 scenario 3 assuming mass timber manufacturing would increase as a material revolution replacing cement and steel in urban construction by wood scales up accordingly Lastly if countries with current low industrialization level e g Africa Oceania and parts of Asia would also make the transition to timber including bamboo then even 90 timber by 2050 scenario 4 is conceivable This could result in storing between 10 million tons of carbon per year in the lowest scenario and close to 700 million tons in the highest scenario The study found that this potential could be realized under two conditions First the harvested forests would need to be sustainably managed governed and used Second wood from demolished timber buildings would need to be reused or preserved on land in various forms 83 Direct air capture Edit This section is an excerpt from Direct air capture edit Flow diagram of direct air capture process using sodium hydroxide as the absorbent and including solvent regeneration Direct air capture DAC is a process of capturing carbon dioxide CO2 directly from the ambient air as opposed to capturing from point sources such as a cement factory or biomass power plant and generating a concentrated stream of CO2 for sequestration or utilization or production of carbon neutral fuel and windgas Carbon dioxide removal is achieved when ambient air makes contact with chemical media typically an aqueous alkaline solvent 84 or sorbents 85 These chemical media are subsequently stripped of CO2 through the application of energy namely heat resulting in a CO2 stream that can undergo dehydration and compression while simultaneously regenerating the chemical media for reuse DAC was suggested in 1999 by Klaus S Lackner and is still in development 86 87 Several commercial plants are planned or in operation in Europe and the US Large scale DAC deployment may be accelerated when connected with economical applications or policy incentives In contrast to carbon capture and storage CCS which captures emissions from a point source such as a factory DAC reduces the carbon dioxide concentration in the atmosphere as a whole 88 Typically CCS is recommended for large and stationary sources of CO2 rather than distributed and movable ones On the contrary DAC has no limitation on sources 89 When combined with long term storage of CO2 DAC is known as direct air carbon capture and storage DACCS or DACS 90 DACCS can act as a carbon dioxide removal mechanism although as of 2022 update it has yet to be profitable because the cost per tonne of carbon dioxide is several times the carbon price Oceans Edit Another proposed form of carbon sequestration in the ocean is direct injection In this method carbon dioxide is pumped directly into the water at depth and expected to form lakes of liquid CO2 at the bottom Experiments carried out in moderate to deep waters 350 3 600 metres 1 150 11 810 ft indicate that the liquid CO2 reacts to form solid CO2 clathrate hydrates which gradually dissolve in the surrounding waters 91 This method too has potentially dangerous environmental consequences The carbon dioxide does react with the water to form carbonic acid H2CO3 however most as much as 99 remains as dissolved molecular CO2 The equilibrium would no doubt be quite different vague under the high pressure conditions in the deep ocean In addition if deep sea bacterial methanogens that reduce carbon dioxide were to encounter the carbon dioxide sinks levels of methane gas may increase leading to the generation of an even worse greenhouse gas 92 The resulting environmental effects on benthic life forms of the bathypelagic abyssopelagic and hadopelagic zones are unknown Even though life appears to be rather sparse in the deep ocean basins energy and chemical effects in these deep basins could have far reaching implications Much more work is needed here to define the extent of the potential problems Carbon storage in or under oceans may not be compatible with the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 93 An additional method of long term ocean based sequestration is to gather crop residue such as corn stalks or excess hay into large weighted bales of biomass and deposit it in the alluvial fan areas of the deep ocean basin Dropping these residues in alluvial fans would cause the residues to be quickly buried in silt on the sea floor sequestering the biomass for very long time spans Alluvial fans exist in all of the world s oceans and seas where river deltas fall off the edge of the continental shelf such as the Mississippi alluvial fan in the gulf of Mexico and the Nile alluvial fan in the Mediterranean Sea A downside however would be an increase in aerobic bacteria growth due to the introduction of biomass leading to more competition for oxygen resources in the deep sea similar to the oxygen minimum zone 94 Geological sequestration Edit The method of geo sequestration or geological storage involves injecting carbon dioxide directly into underground geological formations 95 Declining oil fields saline aquifers and unmineable coal seams have been suggested as storage sites Caverns and old mines that are commonly used to store natural gas are not considered because of a lack of storage safety CO2 has been injected into declining oil fields for more than 40 years to increase oil recovery This option is attractive because the storage costs are offset by the sale of additional oil that is recovered Typically 10 15 additional recovery of the original oil in place is possible Further benefits are the existing infrastructure and the geophysical and geological information about the oil field that is available from the oil exploration Another benefit of injecting CO2 into oil fields is that CO2 is soluble in oil Dissolving CO2 in oil lowers the viscosity of the oil and reduces its interfacial tension which increases the oils mobility All oil fields have a geological barrier preventing upward migration of oil As most oil and gas has been in place for millions to tens of millions of years depleted oil and gas reservoirs can contain carbon dioxide for millennia Identified possible problems are the many leak opportunities provided by old oil wells the need for high injection pressures and acidification which can damage the geological barrier Other disadvantages of old oil fields are their limited geographic distribution and depths which require high injection pressures for sequestration Below a depth of about 1000 m carbon dioxide is injected as a supercritical fluid a material with the density of a liquid but the viscosity and diffusivity of a gas Unmineable coal seams can be used to store CO2 because CO2 absorbs to the coal surface ensuring safe long term storage In the process it releases methane that was previously adsorbed to the coal surface and that may be recovered Again the sale of the methane can be used to offset the cost of the CO2 storage Release or burning of methane would of course at least partially offset the obtained sequestration result except when the gas is allowed to escape into the atmosphere in significant quantities methane has a 80 fold higher global warming potential than CO2 during the first twenty years 96 Saline aquifers contain highly mineralized brines and have so far been considered of no benefit to humans except in a few cases where they have been used for the storage of chemical waste Their advantages include a large potential storage volume and relatively common occurrence reducing the distance over which CO2 has to be transported The major disadvantage of saline aquifers is that relatively little is known about them compared to oil fields Another disadvantage of saline aquifers is that as the salinity of the water increases less CO2 can be dissolved into aqueous solution To keep the cost of storage acceptable the geophysical exploration may be limited resulting in larger uncertainty about the structure of a given aquifer Unlike storage in oil fields or coal beds no side product will offset the storage cost Leakage of CO2 back into the atmosphere may be a problem in saline aquifer storage However current research shows that several trapping mechanisms immobilize the CO2 underground reducing the risk of leakage 97 A major research project examining the geological sequestration of carbon dioxide is currently being performed at an oil field at Weyburn in south eastern Saskatchewan In the North Sea Norway s Equinor natural gas platform Sleipner strips carbon dioxide out of the natural gas with amine solvents and disposes of this carbon dioxide by geological sequestration Sleipner reduces emissions of carbon dioxide by approximately one million tonnes a year The cost of geological sequestration is minor relative to the overall running costs One of the first planned trial of large scale sequestration of carbon dioxide stripped from power plant emissions in the Miller oilfield as its reserves are depleted by BP was not funded 98 In October 2007 the Bureau of Economic Geology at The University of Texas at Austin received a 10 year 38 million subcontract to conduct the first intensively monitored long term project in the United States studying the feasibility of injecting a large volume of CO2 for underground storage 99 The project is a research program of the Southeast Regional Carbon Sequestration Partnership SECARB funded by the National Energy Technology Laboratory of the U S Department of Energy DOE The SECARB partnership will demonstrate CO2 injection rate and storage capacity in the Tuscaloosa Woodbine geologic system that stretches from Texas to Florida Beginning in fall 2007 the project will inject CO2 at the rate of one million tons vague per year for up to 1 5 years into brine up to 10 000 feet 3 000 m below the land surface near the Cranfield oil field about 15 miles 24 km east of Natchez Mississippi Experimental equipment will measure the ability of the subsurface to accept and retain CO2 91 Mineral sequestration Edit Mineral sequestration aims to trap carbon in the form of solid carbonate salts This process occurs slowly in nature and is responsible for the deposition and accumulation of limestone over geologic time Carbonic acid in groundwater slowly reacts with complex silicates to dissolve calcium magnesium alkalis and silica and leave a residue of clay minerals The dissolved calcium and magnesium react with bicarbonate to precipitate calcium and magnesium carbonates a process that organisms use to make shells When the organisms die their shells are deposited as sediment and eventually turn into limestone Limestones have accumulated over billions of years of geologic time and contain much of Earth s carbon Ongoing research aims to speed up similar reactions involving alkali carbonates 100 Several serpentinite deposits are being investigated as potentially large scale CO2 storage sinks such as those found in NSW Australia where the first mineral carbonation pilot plant project is underway 101 Beneficial re use of magnesium carbonate from this process could provide feedstock for new products developed for the built environment and agriculture without returning the carbon into the atmosphere and so acting as a carbon sink 102 One proposed reaction is that of the olivine rich rock dunite or its hydrated equivalent serpentinite with carbon dioxide to form the carbonate mineral magnesite plus silica and iron oxide magnetite Serpentinite sequestration is favored because of the non toxic and stable nature of magnesium carbonate The ideal reactions involve the magnesium endmember components of the olivine reaction 1 or serpentine reaction 2 the latter derived from earlier olivine by hydration and silicification reaction 3 The presence of iron in the olivine or serpentine reduces the efficiency of sequestration since the iron components of these minerals break down to iron oxide and silica reaction 4 Serpentinite reactions Edit Main article Serpentinite Mg olivine Mg2SiO4 carbon dioxide 2CO2 magnesite 2MgCO3 silica SiO2 water H2O Reaction 1 Serpentine Mg3 Si2O5 OH 4 carbon dioxide 3CO2 magnesite 3MgCO3 silica 2SiO2 water 2H2O Reaction 2 Mg olivine 3Mg2SiO4 silica 2SiO2 water 4H2O serpentine 2Mg3 Si2O5 OH 4 Reaction 3 Fe olivine 3Fe2SiO4 water 2H2O magnetite 2Fe3O4 silica 3SiO2 hydrogen 2H2 Reaction 4 102 Zeolitic imidazolate frameworks Edit Main article Zeolitic imidazolate frameworks Zeolitic imidazolate frameworks is a metal organic framework carbon dioxide sink which could be used to keep industrial emissions of carbon dioxide out of the atmosphere 103 Trends in sink performance Edit Cumulative contributions to the global carbon budget since 1850 illustrate how source and sink components have been out of balance causing a nearly 50 rise in atmospheric carbon dioxide concentration 104 One study in 2009 found that the fraction of fossil fuel emissions absorbed by the oceans may have declined by up to 10 since 2000 indicating oceanic sequestration may be sublinear 105 Another 2009 study found that the fraction of CO2 absorbed by terrestrial ecosystems and the oceans has not changed since 1850 indicating undiminished capacity 106 One study in 2020 found that 32 tracked Brazilian non Amazon seasonal tropical forests declined from a carbon sink to a carbon source in 2013 and concludes that policies are needed to mitigate the emission of greenhouse gases and to restore and protect tropical seasonal forests 107 108 The IPCC has noted that oceans and vegetation will progressively absorb a smaller fraction of CO2 emissions and in return create a larger absorption shortcoming 109 An emerging trend is the use of conservative or regenerative agriculture According to Project Drawdown regenerative agriculture could sink 9 43 to 13 4 gigatons of CO2 between 2020 and 2050 This will be a huge contribution to sink performance 110 See also Edit Energy portalAzolla event Biochar Bio energy with carbon capture and storage Carbon capture and storage Carbon cycle Carbon sequestration in terrestrial ecosystems Carbon sinks and removal for climate change mitigation Fluxnet Canada Research Network research initiative on post forest disturbance carbon sinkingSources Edit This article incorporates text from a free content work Licensed under CC BY SA 3 0 IGO license statement permission Text taken from Global Forest Resources Assessment 2020 Key findings FAO FAO To learn how to add open license text to Wikipedia articles please see this how to page For information on reusing text from Wikipedia please see the terms of use References Edit a b What is a carbon sink www clientearth org Retrieved 18 June 2021 Carbon Sources and Sinks National Geographic Society 26 March 2020 Archived from the original on 14 December 2020 Retrieved 18 June 2021 carbon sink European Environment Agency www eea europa eu Retrieved 18 June 2021 Churkina Galina Organschi Alan Reyer Christopher P O Ruff Andrew Vinke Kira Liu Zhu Reck Barbara K Graedel T E Schellnhuber Hans Joachim 2020 Buildings as a global carbon sink Nature Sustainability 3 4 269 276 doi 10 1038 s41893 019 0462 4 ISSN 2398 9629 S2CID 213032074 carbon sequestration Definition Methods amp Climate Change Encyclopedia Britannica Retrieved 18 June 2021 Blakemore R J 2018 Non Flat Earth Recalibrated for Terrain and Topsoil Soil Systems 2 4 64 doi 10 3390 soilsystems2040064 Carbon Sinks A Brief Review Earth Org Past Present Future Retrieved 2 December 2020 Environmental Protection Agency United States 12 August 2013 Overview of Greenhouse Gases EPA Climate Change US EPA Retrieved 17 May 2015 STATE OF THE WORLD S FORESTS 2001 www fao org Retrieved 18 June 2021 Karen Palmer Dallas Burtraw Electricity Renewables and Climate Change Searching for a Cost Effective Policy PDF Resources for the Future Archived from the original PDF on 4 June 2007 Manguiat MSZ Verheyen R Mackensen J Scholz G 2005 Legal aspects in the implementation of CDM forestry projects PDF IUCN Environmental Policy and Law Papers Number 59 Archived from the original PDF on 16 July 2010 Rosenbaum KL Schoene D Mekouar A 2004 Climate change and the forest sector Possible national and subnational legislation FAO Forestry Papers Number 144 Swift Roger S November 2001 Sequestration of Carbon by soil Soil Science 166 11 858 71 Bibcode 2001SoilS 166 858S doi 10 1097 00010694 200111000 00010 S2CID 96820247 Batjes Niels H 1996 Total carbon and nitrogen in the soils of the world European Journal of Soil Science 47 2 151 63 doi 10 1111 j 1365 2389 1996 tb01386 x Batjes 2016 Harmonised soil property values for broad scale modelling WISE30sec with estimates of global soil carbon stocks Geoderma 269 61 68 Bibcode 2016Geode 269 61B doi 10 1016 j geoderma 2016 01 034 Klaus Lorenza Rattan Lala Caroline M Prestonb Klaas G J Nieropc 15 November 2007 Strengthening the soil organic carbon pool by increasing contributions from recalcitrant aliphatic bio macro molecules Geoderma 142 1 2 1 10 Bibcode 2007Geode 142 1L doi 10 1016 j geoderma 2007 07 013 Coral Reefs Biome Underwater Rainforests Retrieved 19 September 2021 a b c Organic Farming Can Cool the World that Chemical Farming Overheated 17 October 2009 Retrieved 18 September 2021 Woolf Dominic Amonette James E Street Perrott F Alayne Lehmann Johannes Joseph Stephen 10 August 2010 Sustainable biochar to mitigate global climate change Nature Communications 1 5 56 Bibcode 2010NatCo 1 56W doi 10 1038 ncomms1053 ISSN 2041 1723 PMC 2964457 PMID 20975722 Mooney Chris The really scary thing about wildfires is how they can worsen climate change The Washington Post Retrieved 24 January 2017 Deforestation amp Carbon Emission Consulting Geologist Retrieved 24 January 2017 Chester Bronwyn 20 April 2000 The case of the missing sink McGill Reporter Retrieved 17 June 2022 Duncan Graham Rowe 24 February 2005 Hydroelectric power s dirty secret revealed New Scientist Archived from the original on 18 May 2008 Retrieved 8 July 2008 C Michael Hogan 28 December 2009 Overgrazing In Cutler J Cleveland ed Encyclopedia of Earth Sidney Draggan Topic Editor Washington DC Environmental Information Coalition National Council for Science and the Environment Archived from the original on 11 July 2010 Timothy J LaSalle Paul Hepperly 2008 Regenerative 21st Century Farming A Solution to Global Warming PDF Report The Rodale Institute Archived from the original PDF on 10 September 2008 Retrieved 19 May 2008 The Farming Systems Trial PDF Rodale Institute Archived from the original PDF on 22 February 2013 Retrieved 20 November 2013 Carbon Dioxide and Our Ocean Legacy by Richard A Feely et al PDF Archived PDF from the original on 1 June 2006 a b c Gao Yang Jia Junjie Lu Yao Sun Kun Wang Jing Wang Shuoyue 2022 Carbon transportation transformation and sedimentation processes at the land river estuary continuum Fundamental Research Elsevier BV doi 10 1016 j fmre 2022 07 007 ISSN 2667 3258 S2CID 251168582 Modified material was copied from this source which is available under a Creative Commons Attribution 4 0 International License Schlunz B Schneider R R 22 March 2000 Transport of terrestrial organic carbon to the oceans by rivers re estimating flux and burial rates International Journal of Earth Sciences Springer Science and Business Media LLC 88 4 599 606 Bibcode 2000IJEaS 88 599S doi 10 1007 s005310050290 ISSN 1437 3254 S2CID 128411658 Blair Neal E Leithold Elana L Aller Robert C 2004 From bedrock to burial The evolution of particulate organic carbon across coupled watershed continental margin systems Marine Chemistry 92 1 4 141 156 doi 10 1016 j marchem 2004 06 023 Bouchez Julien Beyssac Olivier Galy Valier Gaillardet Jerome France Lanord Christian Maurice Laurence Moreira Turcq Patricia 2010 Oxidation of petrogenic organic carbon in the Amazon floodplain as a source of atmospheric CO2 Geology Geological Society of America 38 3 255 258 Bibcode 2010Geo 38 255B doi 10 1130 g30608 1 ISSN 1943 2682 S2CID 53512466 Regnier Pierre Friedlingstein Pierre Ciais Philippe Mackenzie Fred T et al 9 June 2013 Anthropogenic perturbation of the carbon fluxes from land to ocean PDF Nature Geoscience Springer Science and Business Media LLC 6 8 597 607 Bibcode 2013NatGe 6 597R doi 10 1038 ngeo1830 ISSN 1752 0894 S2CID 53418968 a b Bauer James E Cai Wei Jun Raymond Peter A Bianchi Thomas S Hopkinson Charles S Regnier Pierre A G 4 December 2013 The changing carbon cycle of the coastal ocean Nature Springer Science and Business Media LLC 504 7478 61 70 Bibcode 2013Natur 504 61B doi 10 1038 nature12857 ISSN 0028 0836 PMID 24305149 S2CID 4399374 Cai Wei Jun 15 January 2011 Estuarine and Coastal Ocean Carbon Paradox CO2 Sinks or Sites of Terrestrial Carbon Incineration Annual Review of Marine Science Annual Reviews 3 1 123 145 Bibcode 2011ARMS 3 123C doi 10 1146 annurev marine 120709 142723 ISSN 1941 1405 PMID 21329201 Galy Valier Peucker Ehrenbrink Bernhard Eglinton Timothy 2015 Global carbon export from the terrestrial biosphere controlled by erosion Nature Springer Science and Business Media LLC 521 7551 204 207 Bibcode 2015Natur 521 204G doi 10 1038 nature14400 ISSN 0028 0836 PMID 25971513 S2CID 205243485 Nellemann Christian et al 2009 Blue Carbon The Role of Healthy Oceans in Binding Carbon A Rapid Response Assessment Arendal Norway UNEP GRID Arendal a b Macreadie P I Anton A Raven J A Beaumont N Connolly R M Friess D A Kelleway J J Kennedy H Kuwae T Lavery P S and Lovelock C E 2019 The future of Blue Carbon science Nature communications 10 1 1 13 doi 10 1038 s41467 019 11693 w Cathrine E Lovelock Duarte Carlos M 2019 Dimensions of Blue Carbon and emerging perspectives Biology Letters 15 3 20180781 doi 10 1098 rsbl 2018 0781 PMC 6451379 PMID 30836882 a b Ricart Aurora M Krause Jensen Dorte Hancke Kasper Price Nichole N Masque Pere Duarte Carlos M 2022 Sinking seaweed in the deep ocean for carbon neutrality is ahead of science and beyond the ethics Environmental Research Letters 17 8 081003 Bibcode 2022ERL 17h1003R doi 10 1088 1748 9326 ac82ff S2CID 250973225 Hurd Catriona L Law Cliff S Bach Lennart T Britton Damon Hovenden Mark Paine Ellie R Raven John A Tamsitt Veronica Boyd Philip W 2022 Forensic carbon accounting Assessing the role of seaweeds for carbon sequestration Journal of Phycology 58 3 347 363 doi 10 1111 jpy 13249 PMID 35286717 S2CID 247453370 Boyd Philip W Bach Lennart T Hurd Catriona L Paine Ellie Raven John A Tamsitt Veronica 2022 Potential negative effects of ocean afforestation on offshore ecosystems Nature Ecology amp Evolution 6 6 675 683 doi 10 1038 s41559 022 01722 1 PMID 35449458 S2CID 248322820 Carolyn Gramling 28 September 2017 Tropical forests have flipped from sponges to sources of carbon dioxide A closer look at the world s trees reveals a loss of density in the tropics Sciencenews org 358 6360 230 234 Bibcode 2017Sci 358 230B doi 10 1126 science aam5962 PMID 28971966 Retrieved 6 October 2017 Baccini A Walker W Carvalho L Farina M Sulla Menashe D Houghton RA 13 October 2017 Tropical forests are a net carbon source based on aboveground measurements of gain and loss Science 358 6360 230 234 Bibcode 2017Sci 358 230B doi 10 1126 science aam5962 PMID 28971966 Spawn Seth A Sullivan Clare C Lark Tyler J Gibbs Holly K December 2020 Harmonized global maps of above and belowground biomass carbon density in the year 2010 Scientific Data 7 1 112 Bibcode 2020NatSD 7 112S doi 10 1038 s41597 020 0444 4 PMC 7136222 PMID 32249772 a b Does harvesting in Canada s forests contribute to climate change PDF Canadian Forest Service Science Policy Notes Natural Resources Canada May 2007 Archived PDF from the original on 30 July 2013 permanent dead link Global Forest Resources Assessment 2020 Key findings Rome FAO 2020 doi 10 4060 ca8753en ISBN 978 92 5 132581 0 S2CID 130116768 Global Forest Resources Assessment 2020 Key findings FAO 2020 doi 10 4060 ca8753en ISBN 978 92 5 132581 0 S2CID 130116768 Chen JM Ciais Philippe 18 September 2019 Vegetation structural change since 1981 significantly enhanced the terrestrial carbon sink Nature Communications 10 4259 4259 Bibcode 2019NatCo 10 4259C doi 10 1038 s41467 019 12257 8 PMC 6751163 PMID 31534135 Harvey Fiona 4 March 2020 Tropical forests losing their ability to absorb carbon study finds The Guardian ISSN 0261 3077 Retrieved 5 March 2020 Jonathan Amos 15 December 2006 Care needed with carbon offsets BBC Retrieved 8 July 2008 Models show growing more forests in temperate regions could contribute to global warming Lawrence Livermore National Laboratory 5 December 2005 Archived from the original on 27 May 2010 Retrieved 8 July 2008 S Gibbard K Caldeira G Bala T J Phillips M Wickett December 2005 Climate effects of global land cover change Geophysical Research Letters 32 23 L23705 Bibcode 2005GeoRL 3223705G doi 10 1029 2005GL024550 Malhi Yadvinder Meir Patrick Brown Sandra 2002 Forests carbon and global climate Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences 360 1797 1567 91 Bibcode 2002RSPTA 360 1567M doi 10 1098 rsta 2002 1020 PMID 12460485 S2CID 1864078 U S Greenhouse Gas Inventory Reports EPA Archived from the original on 1 June 2010 Retrieved 8 July 2008 a b c d Land Use Land Use Change and Forestry PDF EPA Archived from the original PDF on 23 May 2008 Retrieved 8 July 2008 a b Executive Summary PDF EPA Archived from the original PDF on 18 July 2008 Retrieved 8 July 2008 William H Schlesinger dean of the Nicholas School of the Environment and Earth Sciences at Duke University in Durham North Carolina This Is The Impact Of 1 Million Trees 26 November 2019 Retrieved 18 September 2021 Grant M Domke Sonja N Oswalt Brian F Walters Randall S Morin 6 October 2020 Tree planting has the potential to increase carbon sequestration capacity of forests in the United States PDF PNAS 117 40 24649 24651 Bibcode 2020PNAS 11724649D doi 10 1073 pnas 2010840117 PMC 7547226 PMID 32958649 S2CID 221842058 Archived PDF from the original on 20 October 2020 Fourth Assessment Report AR4 Mitigation of Climate Change Working Group III PDF International Panel on Climate Change p 549 Archived from the original PDF on 4 August 2009 Retrieved 11 August 2009 Ruddell Steven et al September 2007 The Role for Sustainably Managed Forests in Climate Change Mitigation Journal of Forestry 105 6 314 319 J Chatellier January 2010 The Role of Forest Products in the Global Carbon Cycle From In Use to End of Life PDF Yale School of Forestry and Environmental Studies Archived from the original PDF on 5 July 2010 Harmon M E Harmon J M Ferrell W K Brooks D 1996 Modeling carbon stores in Oregon and Washington forest products 1900 1992 Climatic Change 33 4 521 Bibcode 1996ClCh 33 521H doi 10 1007 BF00141703 S2CID 27637103 a b David E Steitz Krishna Ramanujan Kent LaBorde 2003 Ocean Plant Life Slows Down And Absorbs Less Carbon Quirin Schiermeier 22 April 2004 Iron seeding creates fleeting carbon sink in Southern Ocean Nature 428 6985 788 Bibcode 2004Natur 428 788S doi 10 1038 428788b PMID 15103342 S2CID 33727485 Roelofs G 2008 A GCM study of organic matter in marine aerosol and its potential contribution to cloud drop activation Atmospheric Chemistry and Physics 8 3 709 719 Bibcode 2008ACP 8 709R doi 10 5194 acp 8 709 2008 hdl 2066 34516 Michael Markels Jr Richard T Barber 14 17 May 2001 Sequestration of CO2 by ocean fertilization PDF NETL Conference on Carbon Sequestration Archived from the original PDF on 10 September 2008 Retrieved 8 July 2008 Questions and Concerns GreenSea Venture Archived from the original on 15 April 2008 Retrieved 8 July 2008 Mitrovic Simon M Fernandez Amandi Monica McKenzie Lincoln Furey Ambrose James Kevin J 2004 Effects of selenium iron and cobalt addition to growth and yessotoxin production of the toxic marine dinoflagellate Protoceratium reticulatum in culture Journal of Experimental Marine Biology and Ecology 313 2 337 51 doi 10 1016 j jembe 2004 08 014 Visualizing Carbon Storage in Earth s Ecosystems 25 January 2022 Retrieved 31 January 2022 Susan S Lang 13 July 2005 Organic farming produces same corn and soybean yields as conventional farms but consumes less energy and no pesticides study finds Retrieved 8 July 2008 Pimentel David Hepperly Paul Hanson James Douds David Seidel Rita 2005 Environmental Energetic and Economic Comparisons of Organic and Conventional Farming Systems BioScience 55 7 573 82 doi 10 1641 0006 3568 2005 055 0573 EEAECO 2 0 CO 2 Lal Rattan Griffin Michael Apt Jay Lave Lester Morgan M Granger 2004 Ecology Managing Soil Carbon Science 304 5669 393 doi 10 1126 science 1093079 PMID 15087532 S2CID 129925989 Johannes Lehmann Biochar the new frontier Archived from the original on 18 June 2008 Retrieved 8 July 2008 Horstman Mark 23 September 2007 Agrichar A solution to global warming ABC TV Science Catalyst Australian Broadcasting Corporation Retrieved 8 July 2008 Monique Brouillette 17 March 2021 How microbes in permafrost could trigger a massive carbon bomb Nature 591 7850 360 362 Bibcode 2021Natur 591 360B doi 10 1038 d41586 021 00659 y PMID 33731951 S2CID 232297719 One Russian scientist hopes to slow the thawing of the Arctic The Economist 16 December 2020 West Arnhem Land Fire Abatement Project Savanna Information Tropical Savannas Cooperative Research Centre Archived from the original on 3 July 2008 Retrieved 8 July 2008 Eureka Win for West Arnhem Land Fire Project Savanna Information Tropical Savannas Cooperative Research Centre Archived from the original on 3 July 2008 Retrieved 8 July 2008 Ning Zeng 2008 Carbon sequestration via wood burial Carbon Balance and Management 3 1 doi 10 1186 1750 0680 3 1 PMC 2266747 PMID 18173850 Climate Change Global Warming and the Built Environment Architecture 2030 Retrieved 23 February 2007 Processing Natural Gas NaturalGas org Retrieved 9 February 2018 Churkina Galina Organschi Alan Reyer Christopher P O Ruff Andrew Vinke Kira Liu Zhu Reck Barbara K Graedel T E Schellnhuber Hans Joachim April 2020 Buildings as a global carbon sink Nature Sustainability 3 4 269 276 doi 10 1038 s41893 019 0462 4 S2CID 213032074 Retrieved 20 June 2020 Keith David W Holmes Geoffrey St Angelo David Heide Kenton 7 June 2018 A Process for Capturing CO2 from the Atmosphere Joule 2 8 1573 1594 doi 10 1016 j joule 2018 05 006 Beuttler Christoph Charles Louise Wurzbacher Jan 21 November 2019 The Role of Direct Air Capture in Mitigation of Anthropogenic Greenhouse Gas Emissions Frontiers in Climate 1 10 doi 10 3389 fclim 2019 00010 Sanz Perez Eloy S Murdock Christopher R Didas Stephanie A Jones Christopher W 12 October 2016 Direct Capture of carbon dioxide from Ambient Air Chemical Reviews 116 19 11840 11876 doi 10 1021 acs chemrev 6b00173 PMID 27560307 Direct Air Capture Technology Factsheet PDF Geoengineering Monitor 24 May 2018 Archived PDF from the original on 26 August 2019 Retrieved 27 August 2019 Erans Maria Sanz Perez Eloy S Hanak Dawid P Clulow Zeynep Reiner David M Mutch Greg A 2022 Direct air capture process technology techno economic and socio political challenges Energy amp Environmental Science 15 4 1360 1405 doi 10 1039 D1EE03523A ISSN 1754 5692 Erans Maria Sanz Perez Eloy S Hanak Dawid P Clulow Zeynep Reiner David M Mutch Greg A 2022 Direct air capture process technology techno economic and socio political challenges Energy amp Environmental Science 15 4 1360 1405 doi 10 1039 D1EE03523A ISSN 1754 5692 Quarton Christopher J Samsatli Sheila 1 January 2020 The value of hydrogen and carbon capture storage and utilisation in decarbonising energy Insights from integrated value chain optimisation Applied Energy 257 113936 doi 10 1016 j apenergy 2019 113936 S2CID 208829001 a b Brewer Peter G Peltzer Edward T Orr Franklin M Jr 7 May 1999 Direct Experiments on the Ocean Disposal of Fossil Fuel CO2 Science 284 5416 943 945 Bibcode 1999Sci 284 943B doi 10 1126 science 284 5416 943 PMID 10320370 The Christian Science Monitor 28 April 2008 Potent greenhouse gas methane has been rising The Christian Science Monitor Norman Baker Ben Bradshaw 4 July 2005 Carbon Sequestration Retrieved 8 July 2008 Zakem Emily J Mahadevan Amala Lauderdale Jonathan M Follows Michael J 2020 Stable aerobic and anaerobic coexistence in anoxic marine zones The ISME Journal 14 1 288 301 doi 10 1038 s41396 019 0523 8 PMC 6908664 PMID 31624350 S2CID 204758450 Sequestration of Supercritical CO2 in Deep Sedimentary Geological Formations Negative Emissions Technologies and Reliable Sequestration A Research Agenda Report Washington DC The National Academies Press 2019 pp 319 350 doi 10 17226 25259 ISBN 978 0 309 48452 7 Methane A crucial opportunity in the climate fight Environmental Defense Fund Retrieved 18 September 2021 Stephanie Flude Juan Alcade 4 March 2020 Carbon capture and storage has stalled needlessly CO2 storage in depleted oilfields PDF 2009 Archived PDF from the original on 1 October 2015 Bureau of Economic Geology Receives 38 Million for First Large Scale U S Test Storing Carbon Dioxide Underground Jackson School of Geosciences The University of Texas at Austin 24 October 2007 Archived from the original on 11 June 2010 Retrieved 14 April 2010 Carbon capture Technology To Help UK Tackle Global Warming ScienceDaily 27 July 2007 Mineral carbonation project for NSW 9 June 2010 a b Frost B R Beard J S 3 April 2007 On Silica Activity and Serpentinization Journal of Petrology 48 7 1351 1368 doi 10 1093 petrology egm021 New materials can selectively capture CO2 scientists say CBC News 15 February 2008 Global Carbon Budget 2021 PDF Global Carbon Project 4 November 2021 p 57 Archived PDF from the original on 11 December 2021 The cumulative contributions to the global carbon budget from 1850 The carbon imbalance represents the gap in our current understanding of sources amp sinks Source Friedlingstein et al 2021 Global Carbon Project 2021 Earth Institute News Columbia University 18 November 2009 Knorr W 2009 Is the airborne fraction of anthropogenic CO2 emissions increasing Geophysical Research Letters 36 21 L21710 Bibcode 2009GeoRL 3621710K doi 10 1029 2009GL040613 Controversial new climate change results University of Bristol Press release 9 November 2009 Brazilian forests found to be transitioning from carbon sinks to carbon sources phys org Retrieved 16 January 2021 Maia Vinicius Andrade Santos Alisson Borges Miranda Aguiar Campos Natalia de Souza Cleber Rodrigo de Oliveira Matheus Coutinho Freitas de Coelho Polyanne Aparecida Morel Jean Daniel Costa Lauana Silva da Farrapo Camila Lais Fagundes Nathalle Cristine Alencar Paula Gabriela Gomes Pires de Santos Paola Ferreira Gianasi Fernanda Moreira Silva Wilder Bento da Oliveira Fernanda de Girardelli Diego Teixeira Araujo Felipe de Carvalho Vilela Taynara Andrade Pereira Rafaella Tavares Silva Lidiany Carolina Arantes da Menino Gisele Cristina de Oliveira Garcia Paulo Oswaldo Fontes Marco Aurelio Leite Santos Rubens Manoel dos 1 December 2020 The carbon sink of tropical seasonal forests in southeastern Brazil can be under threat Science Advances 6 51 eabd4548 Bibcode 2020SciA 6 4548M doi 10 1126 sciadv abd4548 ISSN 2375 2548 PMID 33355136 Kirn Marda 2016 Climate Literacy From the What of Climate Change to the So What of Personal and Social Change Geological Society of America Annual Meeting in Denver Colorado USA Abstract Geological Society of America doi 10 1130 abs 2016am 287348 Schleien Danny 24 September 2020 We Need To Harness Natural Carbon Sinks To Reverse Climate Change Climate Conscious Retrieved 11 November 2021 External links EditCarbon Capture and Sequestration Technologies Program at MIT Retrieved from https en wikipedia org w index php title Carbon sink amp oldid 1136197135, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.