Carbon project co-benefits for globally threatened species

Claims and complexity

Many carbon projects claim biodiversity co-benefits. Sometimes, it is these co-benefits that motivate the implementation of a project in the first place, with carbon finance utilised to protect or restore ecosystems for the benefit of the wildlife and people they support.

Buyers are willing to pay more for highly rated carbon credits, and projects that claim contributions beyond carbon command a further premium. This suggests that a mature carbon market could put a dent not only in global emissions but also, more broadly, in the widening gap for nature finance ¹.

As with carbon, transparency is key. But unlike carbon, there is no meaningful way to capture all aspects of biodiversity in a single unit of measurement. Moreover, there are a multitude of judgments that can be imposed on the value of one aspect of biodiversity over another, with varying perspectives from different groups of people. Biodiversity is not one thing, neither in measurement nor perceived value, so projects that report on biodiversity all make slightly different claims.

Amid this complexity, one salient and urgent priority is to avoid the extinction of species. The world is losing species at over 1,000 times the normal background rate ². By this measure, we could be entering the fastest decline in global biodiversity in 66 million years - since dinosaur times.

A species is considered threatened with global extinction if it has been assessed as ‘Critically Endangered’, ‘Endangered’, or ‘Vulnerable’ on the IUCN Red List. Other species are classified in lower risk categories (‘Near Threatened’, ‘Least Concern’, or ‘Conservation Dependent’), or else ‘Data Deficient’ if insufficient information is available for a rigorous assessment.

Currently, more than 46,000 species are threatened with extinction, driven to the brink most often by habitat loss due to changes in land and sea use - the same proximate threats that many nature-based carbon projects aim to tackle with climate finance.

In addition to assessing environmental safeguards and mapping project overlap with Key Biodiversity Areas, the BeZero platform now details the numbers and kinds of globally threatened species that could benefit from carbon project activities (Figure 1).

Biodiversity on the BeZero platform

For every nature-based project, we provide a low/medium/high assessment of the project’s potential to protect or restore habitat for globally threatened species. These assessments are made using data from the IUCN Red List and IBAT STAR metrics ³, combined with BeZero’s database of project boundaries and our standardised classification of project activities.

A high score indicates the potential to protect or restore natural habitat in a region of high importance for globally threatened species. The score depends on both the project’s location and its stated activities. For instance, commercial plantations of non-native trees receive a low score regardless of location, whereas projects protecting or restoring natural ecosystems may have higher potential, depending on the number of birds, mammals, and amphibians potentially in that region; the proportion of their global ranges overlapping with the project area; and the degree of threat that they face.

We find that nearly one third of nature-based projects with a BeZero Carbon Rating have a high potential to benefit globally threatened species (Figure 2). Projects in the Peatlands, Mangroves, and Avoided Deforestation sub-sectors have the highest potential, given their locations and activities.

Other project types could also make important contributions to global biodiversity. Currently, however, many of these projects do not protect or restore natural ecosystems or are situated far from geographical hotspots of globally threatened species.

Common threats to climate and biodiversity

When a species is included on the IUCN Red List, assessors record the direct threats, or proximate human activities, that triggered the listing. BeZero has extracted and summarised these IUCN threat types for each BeZero-rated carbon project, indicating how commonly each threat type was recorded for species with geographical ranges that may overlap with a project area.

We find that ‘agriculture and aquaculture’ is the most commonly cited IUCN threat type, followed by ‘biological resource use’ (for example, hunting or logging) and then ‘invasive & other problematic species, genes & diseases’.

For a simpler view and policy relevance, we also map IUCN threat types onto the five key drivers of biodiversity change identified by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) ⁴. Under the IPBES classification, ‘changes in land and sea use’ and ‘direct exploitation of organisms’ rank first or second for the majority of BeZero-rated projects (Figure 3). This mirrors the global situation, with IPBES ranking these two drivers as having had the largest global impact on biodiversity to date, followed by climate change and invasive alien species.

These rankings highlight that the same land and resource use pressures that many carbon projects aim to alleviate for climate impact are also the primary drivers of species extinction risk, while the primary goal of all carbon projects - to mitigate climate change - directly addresses the third key driver of biodiversity change.

Life forms and knowledge gaps

For every nature-based project, we provide a breakdown and ranking of the kinds of IUCN Red List species in or near a project area, grouped by life form and IUCN threat category (Figure 1).

On average, across all rated projects, birds and mammals have the most species listed as globally threatened. These estimates are extracted from global datasets that represent current, incomplete knowledge and so it is important to stress some limitations.

Firstly, despite centuries of scientific work to catalogue life on Earth, our global knowledge base remains patchy and incomplete. This is particularly the case for small-bodied animals with narrow ranges and for species found in the soil, deep sea, forest canopies, or otherwise hard-to-reach locations. Species of fungi, for instance, are especially underrepresented on the biological record.

One study concludes that a staggering 87% of species may still lack formal description ⁵. Clearly, those undescribed species are not included in the Red List assessments used here. However, since known hotspots of biodiversity are likely to house the most undiscovered species ⁶, it follows that existing global priorities should, by and large, remain informative even as new species are catalogued.

Secondly, even for known species, knowledge relating to their range limits and areas of occupancy is incomplete and imprecise. The actual occurrence or potential to colonise a carbon project area depends on site-specific factors such as habitat type and condition, microclimate, barriers to dispersal, and biotic interactions with other species.

The data we summarise are best used as a comparative tool rather than as an absolute measure of the specific species present in, or likely to colonise, any given location.

Assessing project impact

The BeZero Carbon Rating assesses the likelihood that carbon credits deliver their stated climate impact. Our beyond carbon analytics provide complementary information on project safeguards, sustainable development goals (SDG) claims, and now, potential co-benefits for globally threatened species.

It is generally impractical for third parties to independently validate whether specific biodiversity claims are realised on the ground. However, satellite monitoring provides a partial way forward - not in terms of the number or diversity of particular species, but at the ecosystem level by analysing the intactness, connectedness, and functional and structural diversity of habitats.

For instance, the majority of rainforest species live in the forest canopy, while all those in the understorey, on the forest floor, or in the soil depend on the canopy to maintain survivable conditions. Therefore, satellite monitoring of canopy attributes, compared to statistical controls outside the carbon project, is a pragmatic means by which to gauge project impacts on biodiversity. 

BeZero is building these remotely sensed indicators using high-resolution satellite imagery and testing how such indicators relate to on-the-ground biodiversity measurements. These indicators, combined with information on globally threatened species, will provide a toolkit for assessing and comparing the biodiversity co-benefits of carbon projects.

The BeZero platform is constantly evolving. If you have feedback on how you would like to see our biodiversity tools develop, please contact commercial@bezerocarbon.com.

References

1. United Nations Environment Programme. State of Finance for Nature: The Big Nature Turnaround – Repurposing $7 trillion to combat nature loss. Nairobi, Kenya. (2023).

2. Vos, J. M. D., Joppa, L. N., Gittleman, J. L., Stephens, P. R. & Pimm, S. L. Estimating the normal background rate of species extinction. Conserv. Biol. 29, 452–462 (2015).

3. Mair, L. et al. A metric for spatially explicit contributions to science-based species targets. Nat. Ecol. Evol. 5, 836–844 (2021).

4. IPBES. Global Assessment Report on Biodiversity and Ecosystem Services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Brondizio, E. S., Settele, J., Díaz, S. & Ngo, H. T. (eds). IPBES secretariat, Bonn, Germany. (2019).

5. Mora, C., Tittensor, D. P., Adl, S., Simpson, A. G. B. & Worm, B. How many species are there on Earth and in the ocean? PLoS Biol. 9, e1001127 (2011).

6. Joppa, L. N., Roberts, D. L., Myers, N. & Pimm, S. L. Biodiversity hotspots house most undiscovered plant species. Proc. Natl. Acad. Sci. 108, 13171–13176 (2011).

7. Larsen, T. H., Palomino, W., Zeballos, H. & Carrillo, P. Evaluación Biológica Rápida del Paisaje Alto Mayo, San Martin, Perú. RAP Bulletin of Biological Assessment 73. Conservation International, Arlington, VA, USA. (2024).