Global projections of extreme sea levels in view of climate change
Abstract
Global warming is expected to drive increasing extreme sea levels (ESLs) and flood risk along the world's coasts. The present contribution aims to present global ESL projections obtained by combining dynamic simulations of all the major ESL components during the present century, considering the latest CMIP5 projections for RCP4.5 and RCP8.5. Baseline values are obtained combining global re-analyses of tides, waves, and storm surges, including the effects of tropical cyclones. The global average RSLR is projected around 20 and 24 cm by the 2050s under RCP4.5 and RCP8.5, respectively and is projected to reach 46 and 67 cm by the year 2100. The largest increases in MSL are projected along the South Pacific, Australia and West Africa, while the smaller RSLR is projected around East North America, and Europe. Contributions from waves and storm surges show a very weak increasing global trend, which becomes statistically significant only towards the end of the century and under RCP8.5. However, for areas like the East China Sea, Sea of Japan, Alaska, East Bering Sea, as well as the Southern Ocean, climate extremes could increase up to 15%. By the end of this century the 100-year event ESL along the world's coastlines will on average increase by 48 cm for RCP4.5 and 75 cm for RCP8.5. The strongest rise is projected along the Southern Ocean exceeding 1 m under RCP8.5 by the end of the century. Increase exceeding 80 cm is projected for East Asia, West North America, East South America, and the North Indian Ocean. Considering always the business as usual and the year 2100, the lowest increase in ESL100 is projected along the East North America and Europe (below 50 cm). The present findings indicate that, under both RCPs, by the year 2050 the present day 100-year event will occur every 5 years along a large part of the tropics, rendering coastal zones exposed to intermittent flood hazard.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMOS21B..05V
- Keywords:
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- 1222 Ocean monitoring with geodetic techniques;
- GEODESY AND GRAVITY;
- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERAL;
- 4556 Sea level: variations and mean;
- OCEANOGRAPHY: PHYSICAL