Cost-benefit Analysis of Adaptation to Sea Level Rise in Major Vulnerable Regions along the Coast of China

摘要

In this paper, based on the prediction of the global sea level trends in21st century under IPCC SRES A2 scenario with the CCSM3(Community Climate System Model) model, sea level variation in theChina Sea was predicted by the oceanic general circulation model POP(Parallel Ocean Program).Then the absolute sea level rise wasestimated. The relative sea level was calculated by adding thecontribution of land-ice melting and crust subsidence to the absolutesea level. First, the relative sea levels in three major vulnerable regions,i.e., the Bohai bay, Laizhou bay and the Yellow River delta, theYangtze River delta and the coast along Jiangsu and northern Zhejiang,and the Pearl River delta, were predicted in 2050 and 2080. Theprimary impact of sea level rise in major vulnerable regions is that thecoastal lowlands may be submerged. In response to the impact of sealevel rise, the most direct adaptive measure is to heighten and reinforcethe seawalls. Assume that all the existing seawalls reach the standard of100-year recurrence, to respond to the sea level rise, the total cost ofheightening and reinforcing the seawalls was calculated in threevulnerable regions. Based on the ratio of the average annual cost ofheightening and reinforcing seawalls to GDP (Gross DomesticProduct), this paper studied the likely economic impacts on coastalcommunities due to climate change induced sea level rise, put forwardprotection measures and analyzed the reasonability of protection.