Regional issues raised by sea-level rise and their policy implications

Global sea levels are rising and this change is expected to accelerate in the coming century due to anthropogenic global warming. Any rise in sea level promotes land loss, increased flooding and salinisation. The impacts of and possible responses to sea-level rise vary at the local and regional scale due to variation in local and regional factors. Policy responses to the human-enhanced greenhouse effect need to address these different dimensions of climate change, including the regional scale. Based on global reviews and analyses of relative vulnerability, 4 contrasting regions are selected and examined in more detail using local and national assessments. These regions are (1) Europe, (2) West Africa, (3) South, South-East and East Asia and (4) the Pacific Small Islands. Some potential impacts of sea-level rise are found to have strong regional dimensions and regional cooperation to foster mitigation approaches (to reduce greenhouse gas emissions and, hence, the magnitude of climate change) and adaptive solutions to climate change impacts would be beneficial. For instance, in South, South-East and East Asia subsiding megacities and questions about long-term deltaic management are common and challenging issues. The debate on mitigation and stabilisation of greenhouse forcing also requires information on regional impacts of different emission pathways. These results will be provided by integrated models, calibrated against national assessments.