Climate Adaptation Spending and the Measurement of Avoided Economic Losses

Climate adaptation investment aims to reduce the economic consequences of floods, droughts, extreme weather, and other climate-related hazards. Yet expenditure alone cannot demonstrate that economic losses have been prevented. This research examines how avoided economic losses are defined, estimated, and evaluated, drawing on evidence from the United Nations Environment Programme, the World Bank, the World Meteorological Organization, and the Intergovernmental Panel on Climate Change.

The study distinguishes adaptation financing, projected economic benefits, and outcomes supported by evidence after implementation. It examines flood protection, resilient infrastructure, early warning systems, and the challenge of estimating what would have happened without an intervention. The findings emphasize that adaptation effectiveness depends on local exposure, intervention design, and credible comparisons between actual outcomes and alternative scenarios, rather than investment amounts or projected returns alone.