Funding public adaptation to climate-related disasters. Estimates for a global fund

Managing disaster risk is increasingly being considered a key line of response in climate adaptation. While funding support for adaptation has been pledged, rationales for support and cost implications are essentially unclear, which may explain why financing is currently only forthcoming at low levels. Various estimates for the costs of adaptation have been suggested, yet the rationale and robustness of the estimates have been difficult to verify. Focusing on weather-related extreme events, we conduct a global assessment of the public finance costs for financially managing extreme event risks. In doing so, we assess countries’ fiscal disaster vulnerability, which we operationalize as the public sector's ability to pay for relief to the affected population and support the reconstruction of lost assets and infrastructure. Methods employed include minimum-distance techniques to estimate the tail behaviour of country disaster risks as well as the inclusion of non-linear loss and financing resources relationships. We find that many countries appear fiscal vulnerable and would require assistance from the donor community in order to bolster their fiscal resilience. Our estimates may inform decisions pertaining to a global fund for absorbing different levels of country risks. We find the costs of funds covering different risk layers to be in the lower billions of dollars annually, compared to estimates of global climate adaptation which reach to more than USD 100 billion annually. Our estimates relate to today's climate, and while disaster losses have currently not been robustly linked to climate change, physical science has made a strong case in attributing changes in climate extremes to anthropogenic Climate Change. We suggest that estimates of current weather variability and related risks, although also associated with substantial uncertainty, can be interpreted as a baseline for discussion and any future projections of risks.