Reversing biodiversity loss will require more ambitious and accelerated action to strengthen biodiversity policies and translate commitments into effective implementation. Mobilising finance at scale is essential to support these efforts and deliver effective biodiversity outcomes. Financial resources are needed to protect species, ecosystems and genetic diversity, including through effectively managed protected areas; restoration of degraded ecosystems; and supporting transitions to more sustainable patterns of production and consumption. Resources are also needed to strengthen the institutions, monitoring systems and other enabling conditions required for effective action.
The need to mobilise additional biodiversity finance is widely recognised. Target 19 of the Kunming-Montreal Global Biodiversity Framework (KMGBF), for example, calls for a substantial increase in financial resources from all sources and the mobilisation of at least USD 200 billion per year by 2030 to support biodiversity action. Yet despite efforts through international conventions such as the Convention on Biological Diversity (CBD), international organisations, national statistical offices, and private sector initiatives, to track biodiversity finance, the data remains incomplete, fragmented and not always consistent or comparable across countries.
The revised draft CBD report on collective progress towards the KMGBF, for example, estimates biodiversity finance from all sources at USD 32.7 billion in 2023 (CBD, 2026[1]). As this paper shows, this low collective estimate stemming from the 7th National Reports to the CBD reflects poor data coverage across countries and incomplete reporting. The biodiversity finance data are also inconsistent and not comparable across countries, despite the adoption of headline indicators which was intended to address these issues (OECD, 2019[2]).
Assessing progress towards national and international biodiversity finance objectives requires robust information on biodiversity finance flows from both public and private actors. Embedding biodiversity-finance tracking and reporting approaches into established international statistical classifications would reduce duplication, reporting burdens and costs, while improving the consistency and international comparability of data. Better information on biodiversity finance can, in turn, inform policy and investment decisions, help identify financing gaps and provide a stronger evidence base for policymakers, parliaments, auditors, civil society and international partners to evaluate progress towards biodiversity finance objectives and ultimately broader biodiversity goals.
Building on the OECD’s first comprehensive estimate of global biodiversity finance (OECD, 2020[3]), this paper provides a transparent estimate of biodiversity finance across all sources. It compiles and analyses available data on domestic public expenditure, international public finance and private biodiversity finance (i.e. KMGBF headline indicators D1, D2, D3).1 The paper also examines key methodological and data-related challenges for measuring and reporting biodiversity finance and provides proposals to enhance the consistency, comparability, coverage and transparency of biodiversity finance data across countries.
While this paper focuses primarily on the volume of biodiversity finance and how data could be improved, the effectiveness with which finance is mobilised, targeted and deployed also matters for achieving biodiversity outcomes. These issues are examined in complementary OECD work on good practices to mobilise public and private finance (OECD, 2026[4]) and on scaling up biodiversity-positive incentives (OECD, 2025[5]).
This paper is organised as follows: Section 2 presents the key findings for public domestic, public international, and private (domestic and international) finance, together with complementary data on biodiversity-related markets and financial instruments. Section 3 describes the scope and methodological approach. Section 4 assesses data limitations and reporting gaps and proposes options for improving consistency, comparability, coverage and transparency of biodiversity finance data including strengthening links to international statistical classifications. Detailed data sources, processing rules and calculations are provided in the annexes.