This research was published in Nature Climate Change on 2013/06/09. Any usage of the figure in this page requires a written consent from the corresponding authors of the manuscript.

A warmer climate would increase the risk of floods. So far, only a few studies have projected changes in floods on a global scale. None of these studies relied on multiple climate models. A few global studies have started to estimate the exposure to flooding (population in potential inundation areas) as a proxy of risk, but none of them has estimated it in a warmer future climate. Here we present global flood risk for the end of this century based on the outputs of 11 climate models. A state-of-the-art global river routing model with an inundation scheme was employed to compute river discharge and inundation area. An ensemble of projections under a new high-concentration scenario demonstrates a large increase in flood frequency in Southeast Asia, Peninsular India, eastern Africa and the northern half of the Andes, with small uncertainty in the direction of change. In certain areas of the world, however, flood frequency is projected to decrease. Another larger ensemble of projections under four new concentration scenarios reveals that the global exposure to floods would increase depending on the degree of warming, but interannual variability of the exposure may imply the necessity of adaptation before significant warming.

The first column of the figure shows the return period of 20th century 100-year flood discharge at the end of 21st century for different RCP scenarios (most extreme to least extreme emission scenario from top row to bottom row).  The middle column shows the change in 100-year discharge and the last column shows uncertainty. Under most (least) extreme climate scenario, the flood frequency and the magintude of 100-year discharge will increase (decrease) in many regions of the world (blue shades). The uncertainty or spread among different GCMs used in the study is also relatively low in these regions.

Detailed press release for the publication can be found here.

  Top   Home 

HTML Comment Box is loading comments...