Biodiversity Impact Credit

A Biodiversity Impact Credit (BIC) is a transferable biodiversity credit designed to reduce global species extinction risk. The underlying BIC metric, developed by Queen Mary University of London, is given by a simple formula that quantifies the positive and negative effects that interventions in nature have on the mean long-term survival probability of species. The metric is broadly applicable across taxa and ecosystems. Organisations whose overall biodiversity impact is positive in terms of the BIC metric contribute to achieving the objective of the Global Biodiversity Framework to “significantly reduce extinction risk”. A perfect market for BICs would lead to near-optimal allocation of resources to species conservation.

The Task Force on Nature-related Financial Disclosures via their LEAP methodology recommends use of BICs to quantify impacts on species extinction risk in version 1.1 of their disclosure recommendations. The BIC methodology was one of four recognised metrics for assessing extinction risk.^[1]: 221 The first provider of BICs for sale is Botanic Gardens Conservation International (BGCI). The credits are generated by BGCI’s international member organisations by rebuilding the populations of tree species at high risk of extinction under the IUCN red list methodology.

Theory

Definition

Users of BICs distinguish between the metric’s scientific definition and how metric values are estimated through methodologies and approximations suitable for particular contexts. This mirrors the situation with carbon credits, which are designed to quantify avoidance or reductions of atmospheric carbon dioxide load but in practice are estimated using a broad variety of context-specific methodologies.

For a given taxonomic or functional group of ${\displaystyle S}$  species, let ${\displaystyle N_{i}}$  be a measure of the current global population size of the ${\displaystyle i}$ th species. This can be measured, e.g., by the number of mature individuals or population biomass, in some cases even by the number of colonies, whichever approximates total reproductive value^[2] well. Denote by ${\displaystyle \Delta N_{i}}$  the change in the global population of species ${\displaystyle i}$  resulting from a specific intervention in nature. The corresponding Biodiversity Impact Credits are then given by

$${\displaystyle {\text{BIC}}=\sum _{i}^{S}{\frac {\Delta N_{i}}{N_{i}^{*}+N_{i}}},}$$

 

where ${\displaystyle N_{i}^{*}}$  denotes the population size of species ${\displaystyle i}$  at which environmental and demographic stochasticity are of the same magnitude.

Calculation

Depending on the kind of intervention, the system affected and the available data, a variety of methods is available to estimate BICs. Since typical values of ${\displaystyle N_{i}^{*}}$  lie in the range of 1 to 100 adult individuals, the contribution of ${\displaystyle N_{i}^{*}}$  in the definition above is often negligibly small compared to ${\displaystyle N_{i}}$ . The formula then simplifies to

$${\displaystyle {\text{BIC}}=\sum _{i}^{S}{\frac {\Delta N_{i}}{N_{i}}}.}$$

 

In projects that aiming to rebuild the population of a single endangered species ${\displaystyle i}$ , the term associated with that species will often dominate the sum in the formula above so that it simplifies further to

$${\displaystyle {\text{BIC}}={\frac {\Delta N_{i}}{N_{i}}}.}$$

 

When a species restoration project has increased the population of a species by an amount that is much larger than both the original population (and ${\displaystyle N_{i}^{*}}$ ) and no comparable increases in the population of that species have occurred elsewhere, then the species' current population ${\displaystyle N_{i}}$  is nearly identical to the increase ${\displaystyle \Delta N_{i}}$  of the population achieved. In this case, the formula above simplifies to

$${\displaystyle {\text{BIC}}=1.}$$

 

For use over large areas, approximations expressing BICs in terms of Range Size Rarity,^[3] Potentially Disappearing Fraction (PDF) of species,^[4][5] or combinations thereof are available.^[6] In particular, an organisation’s global footprint in terms of BICs is easily computed from PDF-based biodiversity footprints.^[6]

Interpretation

As a simple interpretation, the BIC metric measures the equivalent number of endangered species whose populations have been restored or (for negative BIC) the number of species that should be restored to achieve net zero biodiversity impact. This follows from above approximation that BIC = 1 for the restoration of a single threatened species.^[6]

However, the BIC metric goes beyond simply counting the number of threatened species that have been restored. It takes into account that decline or recovery of a species can be the result of many small impacts by different actors and attributes both positive and negative credits accordingly.^[6]

Compatibility with other standards

The BIC metric aligns with other globally-recognised biodiversity measures such as the Range Size Rarity, the Species Threat Abatement and Recovery Metric (START) by IUCN/TNFD, and the Ecosystem Damage Metric underlying the Biodiversity Footprint for Financial Institutions (BFFI).^[6]

Biodiversity Impact Credits in practice

Rationale

Policy context

The search for standardised systems to quantify biodiversity impacts has gained momentum in light of the accelerating rates of biodiveristy loss worldwide. Traditional biodiversity conservation efforts can lack scalability and are hard to measure: Improving one area of land or river has a different impact on local biodiversity from improving another, so their impacts are difficult to compare. BICs were developed with the aim to simplify assessments of biodiversity change by focusing on reducing species’ extinction risks. The 2022 United Nations Biodiversity Conference emphasised the importance of global collaboration to halt biodiversity loss, marking the adoption of the Kunming-Montreal Global Biodiversity Framework (GBF). BICs aim is to address Target 4 of this framework^[7] “… to halt extinction of known threatened species … significantly reduce extinction risk …” and Target 15: “Take [...] measures [...] to ensure that large transnational companies and financial institutions [...] transparently disclose their [...] impacts on biodiversity [...] along their operations, supply and value chains and portfolios [...] in order to progressively reduce negative impacts on biodiversity …”

Trees as biodiversity keystone species

Trees are at the base of the ecological pyramid. Countless species rely on native trees for survival, including fungi, lichen, insects, birds and other vertebrates.^[8] Repopulating native tree species improves local biodiversity,^[9] helps prevents soil erosion,^[10] conserves water and helps cools the planet^[11] as well as being a carbon store.

Targeting tree extinction risk

BGCI developed the GlobalTreeSearch database which is the only comprehensive, geo-referenced list of all the world’s c.60,000 tree species.^[12] Working with the International Union for Conservation of Nature (IUCN) they then produced the Global Tree Assessment which concluded that more than 17,500 tree species (c.30%) are threatened with extinction.^[13] Finally, BGCI’s Global Tree Conservation Program is the only global programme dedicated to saving the world’s threatened tree species.^[14] Even before BICs were are launched, over 400 rare and threatened tree species had already been conserved in over 50 countries.^[15]

Implementation

Conservation Partnerships

One of the critical components of the BIC system is that it is being driven by conservation organisations like BGCI and their international network of members, and backed by theoretical analyses by Queen Mary University London.^[6] These organisations provide the practical know-how and decades of experience in species conservation, focusing particularly on native trees which play a pivotal role in local ecosystems.

BGCI is now mediating issuance of transferable BIC certificates to organisations who sponsor tree conservation projects by BGCI member organisations.^[16]

Scalability and Market Adoption

The BIC system has been designed for easy adoption and scalability.^[6] This is crucial for engaging financial institutions and other large corporations that require streamlined, global, comparable, and straightforward metrics to set their sustainability goals.^[17]

Reception and Future Prospects

The BGCI unveiled their Global Biodiversity Standard at the 2021 United Nations Climate Change Conference - a global biodiversity accreditation framework.^[18] BICs are due to be formally launched in early 2024.^[16]

Controversy

Biodiversity credits have been criticised by some who say that putting a monetary value on nature is wrong. Others say that they are always bought to offset damage to nature.^[19] In England from 2024 the government is aiming for a net gain in biodiversity,^[20] but it is not yet known how successful these rules to make builders compensate for nature loss will be. ^[21]

References

1. TNFD (2023). Guidance on the identification and assessment of nature- related issues: The LEAP approach version 1.1 (PDF). Taskforce on Nature-related Financial Disclosures. p. 221.
2. Engen, Steinar; Lande, Russell; Saether, Bernt-Erik; Dobson, F. Stephen (2009). "Reproductive value and the stochastic demography of age-structured populations". The American Naturalist. 174 (6): 795–804. doi:10.1086/647930. PMID 19842946. S2CID 10455292.
3. Williams, Paul; Gibbons, David; Margules, Chris; Rebelo, Anthony; Humphries, Chris; Pressey, Robert (1996). "A comparison of richness hotspots, rarity hotspots, and complementary areas for conserving diversity of British birds". Conservation Biology. 10 (1): 155–174. Bibcode:1996ConBi..10..155W. doi:10.1046/j.1523-1739.1996.10010155.x. ISSN 1523-1739.
4. Müller-Wenk, Ruedi (1998). Land use - the main threat to species: how to include land use in LCA. St. Gallen: Institut für Wirtschaft und Ökologie, Universität St. Gallen (IWÖ-HSG). ISBN 978-3-906502-66-3.
5. Goedkoop, Mark; Spriensma, R. (2000-04-17). The Eco-Indicator 99: A Damage Oriented Method for Life Cycle Impact Assessment. Amersfoort, The Netherlands: PRé Consultants B.V.
6. Rossberg, Axel G.; O'Sullivan, Jacob D.; Malysheva, Svetlana; Shnerb, Nadav M. (2023-03-20), A metric for tradable biodiversity credits linked to the Living Planet Index and global species conservation, arXiv:2111.03867
7. "2030 Targets (with Guidance Notes)". Convention on Biological Diversity. 2023-09-21. Retrieved 2023-10-31.
8. "Ecological implications of oak decline in Great Britain". Forest Research. Retrieved 2024-01-10.
9. Manning, Adrian D.; Fischer, Joern; Lindenmayer, David B. (2006-10-01). "Scattered trees are keystone structures – Implications for conservation". Biological Conservation. 132 (3): 311–321. Bibcode:2006BCons.132..311M. doi:10.1016/j.biocon.2006.04.023. ISSN 0006-3207. Retrieved 2024-01-10.
10. Zuazo, Vı́ctor Hugo Durán; Pleguezuelo, Carmen Rocı́o Rodríguez (2009). "Soil-Erosion and Runoff Prevention by Plant Covers: A Review". In Eric Lichtfouse, Mireille Navarrete, Philippe Debaeke, Souchere Véronique, Caroline Alberola (ed.). Sustainable Agriculture. Dordrecht: Springer Netherlands. pp. 785–811. doi:10.1007/978-90-481-2666-8_48. ISBN 978-90-481-2666-8. Retrieved 2024-01-10.{{cite book}}: CS1 maint: multiple names: editors list (link)
11. Abdallah, F.; Chaieb, M. (2012). "The influence of trees on nutrients, water, light availability and understorey vegetation in an arid environment". Applied Vegetation Science. 15 (4): 501–512. Bibcode:2012AppVS..15..501A. doi:10.1111/j.1654-109X.2012.01201.x. ISSN 1654-109X. Retrieved 2024-01-10.
12. "GlobalTreeSearch". Botanic Gardens Conservation International. Retrieved 2024-02-12.
13. EPIC. "Global Tree Assessment". Botanic Gardens Conservation International. Retrieved 2024-02-12.
14. EPIC. "BGCI's Tree Conservation Programme". Botanic Gardens Conservation International. Retrieved 2024-02-12.
15. BGCI; FFI (2021). Securing a Future for the World's Threatened Trees - A Global Challenge. Richmond, UK: Botanic Gardens Conservation International.
16. Reklev, Stian (2023-06-12). "Conservation charity lines up massive project pipeline for biodiversity market". Carbon Pulse. Retrieved 2024-01-14.
17. TNFD (2021). Proposed Technical Scope--Recommendations for the TNFD. Taskforce on Nature-related Financial Disclosures.
18. Sharrock, Suzanne; Smith, Paul (2022). "Introducing the Global Biodiversity Standard". BGjournal. 19 (1): 3.
19. Chandrasekhar, Aruna; Goodman, Joe (2023-09-27). "In-depth Q&A: What are 'biodiversity offsets'?". Carbon Brief. Retrieved 2024-02-15.
20. "Understanding biodiversity net gain". GOV.UK. 2024-02-12. Retrieved 2024-02-15.
21. Weston, Phoebe (2024-02-12). "England brings in biodiversity rules to force builders to compensate for loss of nature". The Guardian. ISSN 0261-3077. Retrieved 2024-02-15.