The data speak for themselves: the wildfire season is currently 27% longer than in 1979 and exposure to extreme heat (above 35°C) has risen by 11% compared to the period 1981-2010. Extreme weather events already cost billions. Wildfires cause between USD 63.5 and 285 billion per year in damages in the United States. In 2022, Europe incurred EUR 40 billion from heat and drought. Increases in temperature also reduce labour productivity. Cities, home to 55% of the world's population today, are particularly exposed to heat waves due to the urban heat island effect that can push temperatures up to 5–7°C higher than surrounding areas.

Adaptation to climate change is therefore rapidly rising on policymakers’ agendas both domestically and internationally. At COP30 in Belém, the Brazilian Presidency will seek a decision on implementing the Global Goal on Adaptation following two years of negotiations that started at COP28 in Dubai.

The OECD’s flagship project “Building Climate and Economic Resilience-Net Zero+” spotlights what a successful approach to adaptation might look like in policymaking. The initiative brings the OECD’s value add to the fore through a systemic approach to climate policymaking, drawing on expertise from across the Organisation. It identified intensifying climate adaptation efforts and investment among the top five priorities for climate action in the years ahead (along with maintaining ambitions, bringing workers and citizens on board, leveraging open markets for trade and investment to accelerate climate action, and closing knowledge gaps with more and better data). Its message is clear: adaptation cannot be an afterthought anymore - it must go hand-in-hand with mitigation if we are to protect lives and economic prosperity.

OECD research shows that effective climate adaptation policymaking should be adaptive in itself, building on a continuous cycle of assessment, planning, implementation and evaluation (Figure 1). This is because adaptation strategies and interventions need to be updated based on evidence of their impact but also in response to evolving climate conditions. What is considered resilient today may not be in a decade or so as climate and weather patterns shift.

Encouragingly, a recent OECD study shows that a growing number of governments have introduced national adaptation plans. A significant gap, however, remains in their ability to measure progress and the impact of adaptation actions. To deal with this gap, some countries have started to introduce legal frameworks that require the development of progress and outcome indicators, as well as formulate adaptation targets. For instance, the 2008 Climate Change Act requires the UK to conduct regular UK-wide Climate Change Risk Assessment and prepare National Adaptation Programme.

Source: (OECD, 2024).

Since the impacts of climate change vary regionally, place-based strategies are a must. Local governments should be central actors in the climate change adaptation process, but often face financial and technical constraints. This is particularly true for regions that already face economic challenges. For instance, the recent OECD Environmental Performance Review of Germany shows that a lack of resources to prepare and implement adaptation strategies is an important barrier for adaptation investments in some German Länder.

Establishing effective national-local co-ordination mechanisms, strengthening local technical capabilities and developing innovative financing mechanisms can help to overcome these challenges. When empowered, subnational governments can be effective drivers of climate resilience.

For the COP, this means ensuring that international frameworks and commitments translate into resources and support for subnational actors who are on the frontline of building climate resilience.

The financing gap is one of the greatest barriers to adaptation. Developing countries alone will need between USD 215 and 387 billion annually this decade for adaptation. In 2022, global adaptation investments amounted to just USD 76 billion. 

Source: (OECD, 2024).

Creating an enabling environment for climate adaptation investments entails aligning policy actions across multiple policy areas to ensure that funding from all sources is mobilised, including from public and private sectors, climate funds and development co-operation.

To this end, national adaptation plans need to be complemented with funding strategies that match financing needs with appropriate funding sources. Updating project appraisal mechanisms can help to account for the uncertainties and non-market benefits of climate resilience. Increasing transparency and disclosure of climate risks in financial markets by e.g. setting disclosure requirements and improving data on climate change impact is also key. With some insurance providers already ending homeowner insurance against climate impacts in certain regions, policies governing insurance markets and risk-transfer arrangements should encourage investment in risk reduction.

In the coming months, the OECD will continue to investigate the policy implications of climate change and adaptation actions, as the initiative “Building Economic and Climate Resilience”  takes a deep dive into the fiscal and macroeconomic consequences of climate change and the role of demand-side policies in building climate resilience.

These themes will also take centre stage at next year’s Green Growth and Sustainable Development (GGSD) Forum taking place at the OECD Headquarters in Paris in July 2026. Under the theme "Building a resilient future through climate adaptation", the Forum will bring together decision-makers, researchers and stakeholders from multiple sectors to explore how governments can increase the climate resilience of societies, ecosystems and economies.