(Panel A) High contemporary values of R’ are distributed globally among the highly populated deltas of Southeast Asia and deltas in developing parts of Africa and the Middle East. (Panel B) Estimated 50-year growth in the future risk trend, R’F, relative to the current R’. The highest relative increases in R’F are in the Rhine, Mississippi, Han, Tone, and Chao Phraya deltas, all systems where current risk is reduced through investments enabled by high GDP and energy costs that are affordable relative to the future scenario.
Zachary Tessler and his colleagues have recently published a research paper in Science, titled Profiling risk and sustainability in coastal deltas of the world. They examined 48 deltas from around the globe to assess changes in regional vulnerability. “Future environmental, geophysical, and societal changes will reposition, in many cases considerably, most of the world’s deltas into a future space of elevated risk. Although potential geophysical changes require additional research at the regional and local scales, our study demonstrates that economic ability and decisions to deploy engineering solutions will be key factors in determining how sustainable deltas become in the long term. Investments that manage the drivers of RSLR, rather than its symptoms, will be necessary to sustain deltas. Although the time horizons are long, acting now is essential, given that rehabilitation will be difficult (if not impossible) to achieve once ground is lost to rising seas.”
Profiling risk and sustainability in coastal deltas of the world
Z. D. Tessler, C. J. Vörösmarty, M. Grossberg, I. Gladkova, H. Aizenman, J. P. M. Syvitski, and E. Foufoula-Georgiou
Science 7 August 2015: 349 (6248), 638-643. [DOI:10.1126/science.aab3574]