Limitations of carbon markets for biodiversity conservation
Carbon markets are often seen as one of the most economically viable means of supporting biodiversity conservation. By enabling financial investment in nature-based carbon projects, which implement interventions that store and accumulate carbon within natural ecosystems, carbon markets can help to expand conservation action across most of the world. However, fundamental misalignments and shortcomings of carbon markets limit their scalability and effectiveness as a tool for biodiversity conservation. In this Perspective, we examine key technical, social and ecological concerns regarding the use of carbon markets for biodiversity conservation. Requirements for additionality, leakage and permanence, although crucial for accurate carbon credit issuance, do not align with broader ecological requirements for biodiversity conservation. Further, commodification of nature through the generation of nature-based carbon credits can create perverse incentives and negative social and ecological impacts that limit the utility of carbon markets for meaningful environmental stewardship. Although emerging approaches to nature-based carbon projects address these concerns to an extent, optimism around these projects’ utility for supporting conservation should be tempered by an understanding of their limitations. Achieving durable biodiversity outcomes will require integrating carbon markets within wider regulatory, community-based and blended-finance frameworks that safeguard ecological integrity, equity and long-term protection beyond the scope of market instruments.
Reducing deforestation is proposed as a global climate action, yet it remains unclear whether carbon projects based on such interventions also maintain forests’ ecological conditions. Here we evaluate 133 projects against matched controls using five ecological-integrity indicators, to show that most projects have mixed, negligible or negative impacts relative to control areas. Results highlight fundamental shortcomings of these climate solutions that limit their ability to safeguard healthy ecosystems and sequester carbon.
Anchoring India's Umbrella Species to Biodiversity and Climate Gains
Policies for nature-based climate solutions and biodiversity conservation are intrinsically linked but seldom aligned, potentially leading to inefficient use of limited environmental budgets. We propose that countries can harness species-specific legislation to simultaneously conserve biodiversity and natural carbon stocks, helping bridge this gap. For instance, this approach has proven effective in India, where tiger conservation has delivered both biodiversity and climate benefits through area-based protection. Expanding this model, we identify additional species with similar potential. Focusing on 160 legally protected and threatened vertebrates in India, we find that protecting the habitat of any one of nine key species could safeguard over a third of the nation's above-ground carbon (∼1.1 GtC) and vertebrate diversity (> 700 species). We further evaluate whether expanding protection within each candidate species’ unprotected habitat aligns with high-value conservation areas outside the existing protected area network. This offers a tangible, underused strategy for aligning India's climate and biodiversity goals.
Turning the tide of climate solutions to save tidal flats
Tidal flats are vital carbon sinks and biodiversity hotspots, yet they face increasing threats from misapplied climate solutions, including mangrove afforestation and renewable energy expansion. Protecting tidal flats from well-intentioned but misapplied solutions is crucial for aligning global climate and biodiversity goals.
Conserving Southeast Asia’s mangroves is a vital natural climate solution, and their protection could be supported by blue carbon credits. However, such financing strategies expose conservation efforts to socioeconomic and climate change permanence risks. Here, we evaluate the potential impacts of permanence risks on the ability of blue carbon financing to safeguard mangroves. Using opportunity costs associated with oil palm, rice and aquaculture land use conversion as indicators of socioeconomic risks, and predicted cyclones and sea-level rise as indicators of climate change risks, we find that 85% of mangroves are likely to experience some form of permanence risk. Diverse funding sources and risk mitigation measures need to be contextualised in a long time horizon to maintain conservation viability into the future. Understanding how these risks interact and affect mangrove conservation efforts over timescales relevant to carbon permanence is key to minimizing risks and ensuring positive socio-ecological outcomes.
Protected areas (PAs) play a crucial role in biodiversity conservation and climate change mitigation. However, ineffective management can lead to biodiversity loss and carbon emissions from deforestation. To address this issue and explore viable solutions, we assessed the impact of PA establishment on avoided deforestation in 80 Southeast Asian PAs using the synthetic control approach. Our results show that 36 PAs successfully prevented 78,910 ha of deforestation. However, the remaining 44 PAs lost 72,497 ha of forest, impacting the habitat of 226 threatened bird and mammal species. Effective management of these reserves could have potentially avoided up to 2.07 MtCO2e/yr in carbon emissions. We estimate that at least $17 million USD per year in additional funding is required to better manage these 44 ineffective PAs and reduce future emissions. Furthermore, we demonstrate that carbon markets have the potential to generate these funds by reducing carbon emissions from deforestation within protected areas. Our findings emphasize that improving PA management is an essential nature-based solution for conserving biodiversity and mitigating climate change.
Climate co-benefits of tiger conservation
Biodiversity conservation is increasingly being recognized as an important co-benefit in climate change mitigation programmes that use nature-based climate solutions. However, the climate co-benefits of biodiversity conservation interventions, such as habitat protection and restoration, remain understudied. Here we estimate the forest carbon storage co-benefits of a national policy intervention for tiger (Panthera tigris) conservation in India. We used a synthetic control approach to model avoided forest loss and associated carbon emissions reductions in protected areas that underwent enhanced protection for tiger conservation. Over a third of the analysed reserves showed significant but mixed effects, where 24% of all reserves successfully reduced the rate of deforestation and the remaining 9% reported higher-than-expected forest loss. The policy had a net positive benefit with over 5,802 hectares of averted forest loss, corresponding to avoided emissions of 1.08 ± 0.51 MtCO2equivalent between 2007 and 2020. This translated to US$92.55 ± 43.56 million in ecosystem services from the avoided social cost of emissions and potential revenue of US$6.24 ± 2.94 million in carbon offsets. Our findings offer an approach to quantitatively track the carbon sequestration co-benefits of a species conservation strategy and thus help align the objectives of climate action and biodiversity conservation.
Gaps and weaknesses in the global protected area network for safeguarding at-risk species
Protected areas are essential to biodiversity conservation. Creating new parks can protect larger populations and more species, yet strengthening existing parks, particularly those vulnerable to harmful human activities, is a critical but underappreciated step for safeguarding at-risk species. Here, we model the area of habitat that terrestrial mammals, amphibians, and birds have within park networks and their vulnerability to current downgrading, downsizing, or degazettement events and future land-use change. We find that roughly 70% of species analyzed have scant representation in parks, or occur within parks that are affected by shifts in formal legal protections or are vulnerable to increased human pressures. Our results also show that expanding and strengthening park networks across just 1% of the world’s land area could preserve irreplaceable habitats of 1191 species that are particularly vulnerable to extinction.
Gains in biodiversity conservation and ecosystem services from the expansion of the planet’s protected areas
Protected areas safeguard biodiversity, ensure ecosystem functioning, and deliver ecosystem services to communities. However, only ~16% of the world’s land area is under some form of protection, prompting international calls to protect at least 30% by 2030. We modeled the outcomes of achieving this 30 × 30 target for terrestrial biodiversity conservation, climate change mitigation, and nutrient regulation. We find that the additional ~2.8 million ha of habitat that would be protected would benefit 1134 ± 175 vertebrate species whose habitats currently lack any form of protection, as well as contribute to either avoided carbon emissions or carbon dioxide sequestration, equivalent to 10.9 ± 3.6 GtCO2 year−1 (28.4 ± 9.4% of the global nature-based climate-change mitigation potential). Furthermore, expansion of the protected area network would increase its ability to regulate water quality and mitigate nutrient pollution by 142.5 ± 31.0 MtN year−1 (28.5 ± 6.2% of the global nutrient regulation potential).