THE DOUBLE TRADE-OFF BETWEEN ADAPTATION AND MITIGATION FOR SEA LEVEL RISE: AN APPLICATION OF FUND

The effects of adaptation and mitigation on the impacts of sea level rise are studied. Without either, the impacts of sea level rise would be substantial, almost wiping out entire nations before 2100; the global effect is much smaller. Adaptation would reduce impacts by a factor 10 to 100. As adaptation depends on socio-economic status, the rank order of most vulnerable countries is not the same as the rank order of most exposed countries. Adaptation would come at a minor cost compared to the damage avoided. Because the momentum of sea level rise is so large, mitigation can reduce impacts only to a limited extent. Stabilising carbon dioxide concentrations at 550 ppm would cut impacts up to 2100 by about 10%. However, if the costs of emission reduction are also factored in, then avoided impacts are less by up to 25% (average 10%). This is partly due to the reduced availability of resources for adaptation, and partly due to the increased sensitivity to wetland loss by adaptation.