State and trends in adaptation report 2025: Small Island Developing States

This year’s State and Trends in Adaptation 2025 (STA25) extends the focus to Small Island Developing States (SIDS), those with the most at stake and the greatest potential for gains through adaptation. Building on the work in Africa, this report presents innovative solutions and policy recommendations aimed at building resilience in these vulnerable nations.

This report documents how increased investments in adaptation measures, along with international efforts to reduce debt, will bring dividends many times higher than the costs. GCA conducted a detailed macroeconomic analysis of six island states, covering all three regions and different climate scenarios, using a Green Economy Model and multiple databases of assets and economic activities in these nations. That analysis shows that each dollar invested in adaptation and resilience measures has a multiplier effort, generating as much as $6.50 in avoided damages and new growth opportunities.