Opinion by Mélisa Cran, RegionsAdapt Program Manager 

Ten years ago, the Paris Agreement placed adaptation alongside mitigation as a global climate priority, recognising that building resilience would be essential to sustainable development and would require action across all levels of government. Yet one important question remained unanswered: what does effective adaptation look like at the regional level?

States and regions were already responding to droughts, floods, heatwaves and other climate impacts, but there was little visibility of their work, few opportunities to learn from one another, and little evidence of how regional action was contributing to global resilience. 

It was in this context that RegionsAdapt – a pioneering initiative dedicated to empowering subnational governments worldwide to adapt to the impacts of climate change – was launched at the UN Climate Change Conference (COP21) by Regions4, the Government of the State of Rio de Janeiro and the Government of Catalonia. 

The initiative was founded on an ambitious idea: to build a global community of states and regions committed to turning climate risks into action. As the first global initiative focused on subnational climate adaptation, RegionsAdapt established a shared framework to help government assess vulnerabilities, plan adaptation strategies, act by implementing adaptation strategies and report progress. 

The initiative was designed to strengthen peer learning, support adaptation on the ground, and show the unique role and contribution of states and regions to the global adaptation agenda. Over the past decade, it has grown into Regions4’s flagship climate initiative, bringing together more than 85 states and regions representing over 400 million people. 

Today, as RegionsAdapt marks its tenth anniversary, Regions4 and CDP are launching the first joint States and Regions Climate Action Summary Report, drawing on 2025 disclosures from 75 states and regions across 19 countries. Together with the stories featured throughout the anniversary campaign, the report offers an opportunity to reflect on how regional adaptation has evolved over the past decade, and where it needs to go next, the report offers an opportunity to reflect on how regional adaptation has evolved over the past decade, and where it needs to go next.  

Adaptation: From Environmental Policy to Institutional Priority 

Perhaps the most important lesson is that adaptation is no longer viewed as an environmental policy alone. Climate risks now shape decisions on infrastructure, water security, agriculture, biodiversity, public health, housing, public finance and territorial planning. Across much of the RegionsAdapt community, adaptation has become a whole-of-government priority. 

This shift is reflected in how regional governments are embedding resilience into the institutions that shape public policy. Catalonia’s ESCACC30 Strategy embeds adaptation across government, while Guanajuato has linked climate objectives to results-based budgeting. In Andalusia, climate budgeting is combined with technical support that has enabled hundreds of municipalities to prepare adaptation plans, and across provinces in Ecuador, climate considerations are increasingly being integrated into territorial development and land-use planning.  

Adaptation has also become increasingly collaborative. Over the past decade, governments have recognised that climate resilience cannot be delivered by any one level of government acting alone. States and regions occupy a unique position between national governments and municipalities, translating national commitments into territorial action while providing technical, financial and institutional support to local authorities. 

This growing role is increasingly recognised in practice. Across Europe, the EU Mission on Adaptation to Climate Change supports regional and local authorities in accelerating resilience through place-based action. In Brazil, initiatives such as AdaptaCidades demonstrate how states can help municipalities strengthen adaptation planning, build technical capacity and coordinate action across territories. 

The findings of the new CDP–Regions4 report reflect this institutional progress. Ninety-three percent of reporting states and regions now have a climate action plan in place, 80% have completed climate risk and vulnerability assessments, and governments disclosed 420 adaptation actions in 2025 alone. These figures point to a significant shift: adaptation is moving from isolated projects towards sustained public policy embedded in institutions and long-term planning. 

The Next Decade Must be About Delivery 

Yet the next decade cannot simply be about producing more strategies. It must be about delivering adaptation at the scale and speed that climate risks now demand. 

The greatest obstacle is no longer recognising the need for adaptation – it is financing it. Although climate impacts continue to intensify, adaptation received only around 3.4 percent of global climate finance in 2023. The new report reflects this challenge: 115 climate-related projects disclosed by states and regions are currently seeking finance, while limited budgetary capacity remains one of the most frequently reported barriers to implementation. 

Closing this gap will require more than increasing overall funding. It will require finance that reaches the territories where resilience is built, stronger support for project preparation and investment readiness, and greater recognition of the role that subnational governments play in delivering national and global adaptation objectives. 

The first decade of RegionsAdapt demonstrated that regional governments can lead climate adaptation. The second must ensure they have the resources, partnerships and recognition to deliver it at scale. 

This means continuing to advocate for the integration of states and regions into Nationally Determined Contributions, National Adaptation Plans and the implementation of the Global Goal on Adaptation. It means strengthening climate data, monitoring systems and technical capacity. And it means ensuring that adaptation finance reaches the regional and local governments responsible for turning policy into action. 

But it also means evolving how we work. Alongside continued advocacy and peer learning, RegionsAdapt will increasingly focus on technical assistance, adaptation finance readiness and stronger territorial collaboration. We are also exploring new Country Chapters, bringing regions together within the same country to strengthen peer learning, support municipalities and reinforce multilevel governance. Brazil is one of the first countries where we are exploring this model with partners. 

The new CDP–Regions4 States and Regions Climate Action Summary Report, together with the stories shared throughout the RegionsAdapt tenth anniversary campaign, demonstrates that adaptation is no longer a future ambition. Across every continent, regional governments are embedding resilience into public institutions, strengthening collaboration across levels of government and preparing communities for a changing climate. 

The past decade showed that regions can lead adaptation. The next must ensure they have the support to deliver it. 

Mélisa Cran
RegionsAdapt Program Manager
The views expressed in this commentary are from the author only