Introduction Climate finance is expanding rapidly. Globally, tracked climate finance reached about $1.46 trillion in 2022, more than double 2018 levels, according to the Climate Policy Initiative. Yet current financing remains far below estimated needs, particularly in developing countries. In Asia and the Pacific, climate investment gaps remain large. The Asian Development Bank (ADB) estimates that annual climate adaptation investment needs could range from $102 billion to $431 billion, while emerging and developing Asia will require at least $1.1 trillion annually for mitigation and adaptation investments. Governments across the region are therefore scaling up public investment in climate action. Public budgets, concessional loans, grants, guarantees, and tax incentives are supporting renewable energy, resilient infrastructure, flood protection, water systems, early warning systems, and climate-smart agriculture. In 2024, ADB committed $12.3 billion in climate finance. Expanding climate finance requires stronger accountability systems. Policymakers must mobilize climate finance while ensuring that public resources are managed transparently and effectively and support measurable climate outcomes. Climate Finance Is Growing Faster than Accountability Systems Climate finance discussions have often focused primarily on mobilizing additional capital. Yet increasing the volume of finance does not automatically guarantee better climate outcomes. Without strong oversight, climate spending can be poorly targeted, fragmented across institutions, or difficult to evaluate. Projects may be classified as climate related without clear evidence of long-term resilience or emissions impact. In some cases, governments can track funding allocations but not whether investments delivered intended results. Climate finance is receiving greater scrutiny. Developed countries provided and mobilized $115.9 billion in climate finance for developing countries in 2022, surpassing the long standing $100 billion annual goal for the first time. However, the target was achieved 2 years later than originally promised, and questions remain about the quality, accessibility, and effectiveness of climate finance. Public climate finance often absorbs early-stage risk in climate action. Public resources support enabling infrastructure, assist vulnerable communities, and help mobilize private investment. They also help attract additional financing. Well-managed public climate finance can strengthen confidence among citizens, development partners, and investors. Weak oversight or unclear results can undermine trust in climate related institutions and investments. Why Technical Tools Alone Are Not Enough Many countries are introducing reforms to strengthen climate finance governance. Climate budget tagging helps governments identify climate related expenditures. Green taxonomies help define climate aligned investment. Public investment management reforms can also improve project appraisal and selection. These measures alone do not ensure accountability. Climate budget tagging can show that resources were allocated to climate related activities, but it does not show whether programs were well designed, efficiently implemented, or achieved intended results. Similarly, green taxonomies can classify investments as climate aligned, but they do not show whether public resources were used efficiently and transparently or whether investments delivered measurable climate outcomes. As climate spending grows, governments need institutions that can independently assess whether climate finance systems are delivering results and public value. The Role of Supreme Audit Institutions Supreme Audit Institutions (SAIs) are well placed to strengthen climate finance accountability. SAIs are independent public institutions mandated to oversee the use of public resources and audit government operations. Traditionally, their work has focused on financial and compliance audits. Climate finance, however, requires broader oversight across institutions and sectors. Climate spending often cuts across sectors, agencies, and funding sources. A flood protection project may involve infrastructure agencies, local governments, ministries of finance, environmental authorities, and external development partners. Renewable energy programs may combine subsidies, guarantees, public investment, and private sector participation. Climate adaptation projects may produce results over long time periods, making outcomes more difficult to assess in the short term. Assessing whether funds were spent according to established rules is no longer sufficient. Governments and citizens also need to know whether climate spending is coordinated, effective, and delivering climate and development results. SAIs can assess climate finance across the whole of government. Unlike project level verifiers or sector regulators, SAIs can examine whether ministries of finance, planning agencies, sector ministries, and implementing institutions are managing climate finance transparently, efficiently, and in a results-oriented manner. Guidance from the International Organization of Supreme Audit Institutions (INTOSAI) recognizes that existing audit approaches, including financial, compliance, and performance audits, can be applied to climate change and climate finance. Performance auditing can help assess whether public climate spending is achieving intended results and whether governments are managing climate risks effectively. SAIs do not replace regulators, carbon market institutions, third party verifiers, or private assurance providers. Regulators oversee compliance and market conduct, while third party verifiers may validate emissions reductions or sustainability claims. Carbon markets and disclosure systems also support investment decisions and market transparency. SAIs provide independent assurance on the performance of public systems and the use of public resources. Their mandate allows them to identify gaps in coordination, implementation, transparency, and accountability across government institutions. Why Public Trust Matters for Climate Finance Climate finance depends on public trust and effective public oversight. Citizens need confidence that public resources are protecting communities and strengthening resilience. Governments require reliable information on what is working and where implementation challenges remain. Development partners need confidence that financing is being used effectively, while private investors rely on strong public systems to mobilize additional capital. The United Nations Environment Programme estimates that the adaptation finance gap for developing countries ranges from $194 billion to $366 billion annually. With available resources still far below estimated needs, climate finance must be traceable, targeted, and linked to measurable outcomes. Strengthening Accountability for the Climate Transition Strong public accountability can strengthen climate finance systems. Independent assessments by SAIs can improve policy design, strengthen implementation, support public financial management, and build confidence in climate related institutions. Climate investment across Asia and the Pacific will continue to grow. The effectiveness of climate finance depends not only on the volume of resources mobilized, but also on transparent and effective management of those resources. Development partners, including ADB, are supporting countries in strengthening climate budgeting, public investment systems, and institutional capacity. This support should also strengthen the capacity of SAIs. Climate finance depends on trust, which in turn depends on credible systems of public accountability. As governments scale up climate action, SAIs can strengthen accountability, improve results, and support effective management of public climate finance. Resources Asian Development Bank (ADB). 2024. Asia-Pacific Climate Report 2024. ADB. 2024. Climate Change Financing at ADB. ADB. 2026. Guide on the Role of Supreme Audit Institutions Toward Achieving Climate Objectives. Climate Policy Initiative. 2024. Global Landscape of Climate Finance 2024. International Monetary Fund. 2024. Unlocking Climate Finance in Asia Pacific. INTOSAI Working Group on Environmental Auditing. 2022. Auditing Climate Finance: Research and Audit Criteria for Supreme Audit Institutions. INTOSAI Working Group on Environmental Auditing. 2025. Global Climate Adaptation Audits for a Resilient Future: Lessons and recommendations from Supreme Audit Institutions. Organization for Economic Co-operation and Development. 2024. Developed countries materially surpassed their USD 100 billion climate finance commitment in 2022. UNEP. 2023. Adaptation Gap Report 2023: Underfinanced. Underprepared. Inadequate Investment and Planning on Climate Adaptation Leaves World Exposed. Ask the Experts Anjun Israr Senior Public Sector Specialist, Sector Group 3. Asian Development Bank Anjum Israr is a senior governance and development finance professional with experience in strategic planning, institutional strengthening, fiscal policy, and reform implementation across a range of country contexts. He has worked with multilateral and bilateral development institutions as well as the private sector, contributing to country programs, policy dialogue, resource mobilization, knowledge products, and reform initiatives. His work has supported governments in areas such as fiscal management, climate-responsive public finance, digital transformation, accountability, and the implementation of reform priorities. Asian Development Bank (ADB) The Asian Development Bank is a leading multilateral development bank supporting sustainable, inclusive, and resilient growth across Asia and the Pacific. Working with its members and partners to solve complex challenges together, ADB harnesses innovative financial tools and strategic partnerships to transform lives, build quality infrastructure, and safeguard our planet. Founded in 1966, ADB is owned by 69 members—49 from the region. Follow Asian Development Bank (ADB) on Leave your question or comment in the section below: View the discussion thread.