Biodiversity finance is a complex and fragmented landscape involving multiple public and private actors, financial instruments and channels across the real economy and financial sector (Figure 2). Ideally, all components of a global estimate would be measured at the same point in the financial value chain. In practice, however, the available data are recorded at different stages, including budget allocations, commitments, disbursements, investments, transactions and final expenditure. These measures are not necessarily additive, as the same underlying resources may be captured more than once (e.g. as a financing commitment, an investment by an intermediary, a project-level transaction and expenditure by the final recipient). A robust estimate therefore requires clear definitions, consistent inclusion rules and careful aggregation to minimise overlap and avoid double counting.
An overview of global biodiversity finance
Note: DFIs = development finance institutions. HNWI = high net worth individuals. IPLCs = Indigenous Peoples and local communities. SMEs = Small and medium-sized enterprises.
Source: Adapted from OECD (2026[4]), Mobilising Public and Private Finance for Biodiversity: Good practices in unlocking capital for nature.
For the purposes of this paper, biodiversity finance comprises financial resources intended to contribute to the conservation, sustainable use or restoration of biodiversity. It includes finance for which biodiversity is the primary objective and, where a documented methodology permits, finance for which biodiversity is a secondary objective. It does not intend to account for finance for activities that may incidentally benefit biodiversity but for which biodiversity is not an identified objective. In practice, however, some country-reported estimates may include such expenditure, for example where a share of sectoral spending is assumed to benefit biodiversity.1
International statistical classifications and other reporting approaches use different terms such as primary and secondary purposes, direct and indirect finance, and principal and significant objectives to describe related but not necessarily identical concepts (Table 2). This paper retains the terminology used by each underlying source.
Notes: Unlike primary-purpose expenditure, direct and indirect finance are not terms used in (or formally defined) in international statistical classification systems. Interpretation of the terms direct and indirect therefore vary, including whether they refer to expected (or assumed) benefits, rather than the intended purpose.
Source: (EC, 2024[9]), Annex: Classification of environmental purposes (CEP) and policy areas; (OECD, 2025[10]), Converged Statistical Reporting Directives for the Creditor Reporting System (CRS) and the Annual DAC Questionnaire; (TOSSD, 2026[11]), www.tossd.org/content/dam/tossd/en/methodology-pdfs/reporting_instructions.pdf; (UNDP, 2018[12]), BIOFIN 2018 Workbook; (UNSD, 2000[13]), Classifications of Expenditure According to Purpose; (UNSD, 2025[14]), Draft Guidance Note C4: Primary and Secondary Purpose: Version for Discussion at the SEEA Central Framework Technical Committee Meeting.
Where biodiversity is of secondary purpose, significant or indirect expenditure, only part of the expenditure may be attributable to biodiversity. CBD National Reports reflect diverse national approaches, with some countries reporting only direct biodiversity expenditure (e.g. using GFS data classified according to COFOG or EPEA data classified according to CEP primary purpose expenditure) and others including indirect expenditure, either in full or through attribution coefficients (see section 4 and Annex A for further detail). Limited reporting detail also makes it difficult to assess whether activities with only incidental biodiversity benefits have been included. As a result, domestic public expenditure estimates are not necessarily comparable across countries. A comparison of biodiversity expenditure across the three data sources when countries have data across all three, shows no discernible trends across these – i.e. one is not consistently higher or lower than the other (see Figure A A.1 in Annex A).
This paper seeks to provide a comprehensive global estimate of biodiversity finance based on available data, and therefore covers public and private actors, domestic and international flows, and biodiversity-related finance across all relevant policy areas, including sectors such as agriculture, fisheries, forestry and tourism (OECD, 2020[3]). It intends to capture finance flows within and from all countries, whilst acknowledging data for some countries are unavailable or incomplete. In this context, while the analysis does not include data from the United States on domestic expenditure, available data on public international finance and private finance originating from the United States are included, as they contribute to global flows relevant to the USD 200 billion target.2 For the purposes of this paper, the USD 200 billion target is used as a benchmark against which the global biodiversity finance estimate is assessed.
3.1.1. Measurement and aggregation
Ideally, all components of a global estimate would be measured at the same point in the financial value chain. In practice, the available data are distributed across several points, including budget allocations, commitments, disbursements, investments, transactions and final expenditure. These measures are not necessarily additive: the same underlying resources may be recorded as a financing commitment, an investment by an intermediary, a project-level transaction and expenditure by the final recipient.
The paper therefore adopts a conservative approach to aggregation. Estimates are combined only where they are sufficiently comparable and where the risk of overlap can be reasonably excluded. Data that may duplicate a more comprehensive estimate, or that represent different stages of the same financing chain, are presented separately rather than added to the total. Where uncertainty exists, the methodology therefore intentionally favours avoiding overestimation.
Additional indicators of market size or financial activity are also presented separately. Examples include assets under management, capital commitments, bond issuance and transaction values for biodiversity-related carbon credits. These indicators provide useful information on the development of biodiversity-related markets and financial instruments, but they should not be interpreted as equivalent to expenditure or as automatically additive to the total estimates of public and private biodiversity finance presented in this paper.
The estimates represent the average annual volume of biodiversity finance during 2023-25, based on the latest observations available within that period. Where three annual observations are available, a three-year average is used; where data are available for only one or two years, the estimate is based on those observations. The aggregate is therefore not a balanced three-year average and should not be interpreted as an estimate for a single calendar year. All values are expressed in constant 2024 United States dollars.
Trend comparisons are based on the latest comparable periods available for each dataset and therefore do not necessarily align exactly with the 2023-25 reference period used for the aggregate finance estimates.
3.1.2. Overview of data sources
The public domestic expenditure estimate is based on data from CBD National Reports, Government Finance Statistics classified under COFOG Group 05.04 Protection of biodiversity and landscape, and Environmental Protection Expenditure Accounts classified as CEP Group 0502 Protection of biodiversity and landscapes. It covers 104 countries and the European Union, including 64 Parties that submitted quantitative data for at least one year between 2023 and 2025 in their CBD 7th National Reports.
International public finance is estimated based on data from the OECD Creditor Reporting System and the Total Official Support for Sustainable Development while addressing possible risk of double counting. Development-finance activities for which biodiversity is a principal or significant objective are identified based on a combination of Rio markers (for CRS only), Sustainable Development Goal tags, purpose code and keyword searches, and attribution methodologies.3 Official development assistance, other official flows and official private-sector instruments are treated as public finance according to the source of the resources; private finance mobilised through official development finance interventions is reported separately.
Private finance combines return-seeking investment and non-return-seeking finance. The investment estimate draws on data compiled by Forest Trends and The Nature Conservancy (Bennett et al., 2026[7]). Philanthropic finance is derived from OECD Creditor Reporting System and the OECD Private Philanthropy for Development database, after removing overlaps. Additional information is drawn from an analysis of published budgets of eight large biodiversity-focused NGOs: African Parks Network, BirdLife International, Conservation International, Fauna & Flora International, the Royal Society for the Protection of Birds, The Nature Conservancy, the Wildlife Conservation Society, and the World Wide Fund for Nature Network.
Market transactions, capital commitments, bond issuance and other non-additive indicators are reported separately. Further detail on data sources and methodology is provided in Annex A.
← 1. For example, in the BIOFIN Workbook (UNDP, 2024[28]), biodiversity expenditure is counted not just when activities intend to benefit biodiversity; coefficients are also applied to activities where “the objective is almost non-existent in policy articulation and framed as unintended impact”.
← 2. Earlier estimates of global biodiversity finance prior to the adoption of Target 19, such as (OECD, 2020[3]) and (Deutz et al., 2020[27]), included the United States.
← 3. TOSSD does not use the OECD DAC Rio Markers.