Countries are facing growing economic, social and environmental challenges, increasing the urgency of building more resilient and inclusive economies, communities, and ecosystems. Addressing these challenges will require substantial investment, particularly in emerging and developing economies. International commitments and frameworks provide important direction, but achieving these goals will require significantly greater capital mobilisation while offering significant opportunities for growth and development.
It is estimated that US$4 trillion annually is needed to close the sustainable development financing gap, alongside US$300 billion per year by 2035 for climate finance and US$200 billion per year by 2030 to reverse nature loss. These financing needs must be addressed in an integrated manner, alongside social and economic development needs, calling for new approaches to development and growth that enable countries to leapfrog towards more inclusive, resilient and sustainable development pathways.
The central question is, therefore, not whether capital exists, but why it is not flowing and how conditions that enable financial flows towards sustainable development objectives at scale can be created.
While public finance cannot bridge the gap on its own, several structural barriers continue to limit private financial flows. Fragmented policy, regulatory uncertainty, insufficient incentives and market-creation mechanisms, and the lack of scalable, bankable projects all discourage capital formation. Private finance also continues to face a range of real and perceived risks in emerging and developing economies. These include macroeconomic volatility, currency and political risks, insufficient market transparency, and high transaction costs.
Blended finance has emerged as an important response, using public and concessional resources to mitigate risks, improve investment attractiveness, and create pathways for private capital to participate in sustainable development at scale. However, addressing investment barriers requires more than structuring individual transactions. It requires a broader systems approach that strengthens the conditions under which capital can flow.
Drawing on UNEP’s experience, mobilising private finance is most likely to scale when four interconnected pillars work together: a supportive enabling environment, strategic deployment of public finance, industry innovation that creates investable opportunities, and private finance that brings capital at scale.
- Enabling Environment
A strong enabling environment is the foundation needed to reduce investment uncertainty and build confidence for long-term decisions. This includes policies based on long-term plans at national and regional levels, such as NDCs, NBSAPs alongside supportive financial regulations, sustainable finance frameworks and roadmaps, and transparent market information. Together, these elements create the conditions for translating climate and nature ambitions, including just transition objectives, into investable opportunities.
This includes supporting governments with national roadmaps, institutional architecture, macroeconomic planning, sustainable finance regulation and taxonomies, and climate risk assessments. UNEP, as part of its mandate, has led the development of sustainable finance taxonomies in Brazil, Costa Rica, Panama and ASEAN, taxonomy pilots in Chile, and climate-risk assessments in Panama and Costa Rica. Through support to the Coalition of Finance Ministers for Climate Action, UNEP is helping 103 Finance Ministries integrate climate and nature considerations across their mandates and strengthening their role in mobilising private finance and developing and deploying blended-finance approaches.
- Public Finance
Public finance remains essential, not only as a source of capital or as a de-risking tool, but also for its catalytic role in creating an enabling investment environment. While it has a fundamental role in providing services that are critical to resilient economies and societies, when deployed strategically through instruments such as concessional finance and guarantees, it can attract private capital at scale particularly where commercial returns are insufficient to attract private finance.
Alongside fiscal reforms, budget systems that align with sustainability, and the integration of environmental externalities into economic decision-making, it can help demonstrate the value of investments and identify where concessional resources are most needed.
UNEP supports governments on fiscal policy design and public finance strategies that improve investment conditions and unlock capital flows. Initiatives such as the Transformational Finance for Climate Group brings together public and private financial institutions and other stakeholders to identify and address structural barriers to climate investment, strengthen the effectiveness of financing approaches and accelerate the mobilisation of capital towards transformational climate outcomes. Through the Net-Zero Nature Positive Accelerator (NZNPA), UNEP also helps ministries of finance, regulators and development banks, such as ADB and CAF, to create policy and financing frameworks that channel public and private capital towards national transition priorities, and develop pipelines of bankable projects that build on these enabling policy environment reforms.
- Industry Innovation
Science-based analysis of high-impact sectors can help identify pathways, technology and policy priorities, uncover investment opportunities, and support the pipeline of bankable projects. At the same time, new financial products, risk-sharing mechanisms, sustainability-linked instruments, and project aggregation approaches can overcome barriers related to scale, complexity, and transaction costs. This can be achieved through a combination of innovative policy measures, public incentives, innovative revenue models, and catalytic capital.
Initiatives such as Innovative Finance for the Amazon, Cerrado and Chaco (IFACC), created by The Nature Conservancy, Tropical Forest Alliance and UNEP, are designed around exactly this principle: making sustainable land use and restoration financially competitive while reducing risks for investors. IFACC aims to mobilise US$10 billion by 2030 and has already supported approximately US$954 million through aligned financial products supporting deforestation- and conversion-free agriculture.
- Private Finance
Banks, insurers and investors bring the scale and expertise required to support sustainable development outcomes by mobilizing capital.
Through the UNEP Finance Initiative (UNEP FI), UNEP has been working with a global network of over 550 banks, insurers and investors representing trillions of dollars in assets and financing capacity. Flagship initiatives such as the Principles for Responsible Banking (PRB), Principles for Sustainable Insurance (PSI), The Forum for Insurance Transition (FIT) and the Net-Zero Asset Owner Alliance (NZAOA) have helped strengthen the commitment and readiness of financial institutions through guidance, training, and dedicated workstreams on mobilizing capital for emerging markets and developing economies. These efforts have identified practical approaches to scaling investment and finance more effectively.
These four interconnected pillars can support finance strategies that mobilize private finance at scale, and allow governments and development finance institutions to effectively use grants, guarantees, technical assistance and concessional financing to address specific market failures and reduce investment risks that private actors are unable or unwilling to absorb on their own.
This integrated approach requires an important shift in thinking. The goal is not simply to structure more blended-finance transactions, it is to support governments in building an attractive environment where capital can flow more effectively and at greater scale. Countries such as Brazil, Indonesia, Singapore and South Africa demonstrate that when the right enabling conditions are in place, private capital follows. Blended finance can play a critical catalytic role, but it is most effective when deployed as part of broader national strategies that combine them with enabling policies, public finance, innovation and private sector participation.
The message is simple: create the right conditions, and capital will follow. Only through such a systemic approach can sustainable development financing be mobilised at the scale required to meet today’s environment, social and development challenges.