Adaptation Projects Return 2.1x Their Cost
A Swiss Re Institute review finds climate adaptation investments in emerging markets have a median benefit-cost ratio of 2.1.
Updated on Nov. 10, 2026 in Forecasts
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The Swiss Re Institute reviewed 42 World Bank and Asian Development Bank projects and found climate adaptation investments in emerging markets generate a median benefit-cost ratio of 2.1. Some interventions returned roughly ten times their cost.
Why it matters
The analysis highlights a measurement gap: only 23% of 651 development bank completion reports quantified avoided losses. Insured natural catastrophe losses are projected to rise from $107 billion in 2025 to $186 billion by 2030, raising the stakes of how adaptation is valued.
The analysis reviewed 42 projects with a combined value of $7.9 billion, drawn from 651 completion reports covering 2015 to 2025. Only 19% of those reports attempted an adaptation-specific benefit-cost ratio, leaving most returns unverified.
The players
Swiss Re Institute
The research arm of Swiss Re, one of the world's largest reinsurers, which publishes analysis on climate and catastrophe risk.
World Bank
An international financial institution that funds development projects across emerging economies, including climate adaptation infrastructure.
Asian Development Bank
A regional development bank headquartered in Manila that finances infrastructure and resilience projects across Asia and the Pacific.
The details
The Swiss Re Institute examined projects that directly addressed physical natural catastrophe hazards. Structural flood protection and resilient housing reconstruction each had a median ratio of 2.5, while hydrometeorological forecasting ranged from 0.3 to 9.6.
Timeline
2015 to 2025: period covered by the 651 development bank project completion reports reviewed.
2025: insured natural catastrophe losses reached $107 billion.
2030: insured natural catastrophe losses are projected to reach $186 billion if current growth trends persist.
Seasonal Patterns
The Swiss Re Institute projects insured natural catastrophe losses could grow at a 5% to 7% annual trend, reaching $186 billion by 2030. Insured flood losses in Europe are already rising at a compound rate of about 5%, making adaptation returns increasingly relevant to long-term climate planning.
Communities in flood-exposed regions should track whether local infrastructure projects report measured avoided losses, since unquantified benefits make it harder to prioritize protection. Residents of high-risk areas can ask local authorities whether resilient housing and flood defenses are funded in current plans.
The takeaway
Adaptation spending tends to pay back well, but that return is only visible when it is measured. Tracking avoided losses in project reporting would make the case for protection far clearer to funders and the public.
Further reading
For the longer outlook on how these losses are expected to develop, see Forecasts.
Source note: This article includes information reported by Risk & Insurance.
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