Extreme sea levels at different global warming levels

The Paris agreement focused global climate mitigation policy on limiting global warming to 1.5 or 2 degrees C above pre-industrial levels. Consequently, projections of hazards and risk are increasingly framed in terms of global warming levels rather than emission scenarios. Here, we use a multimethod approach to describe changes in extreme sea levels driven by changes in mean sea level associated with a wide range of global warming levels, from 1.5 to 5 degrees C, and for a large number of locations, providing uniform coverage over most of the world's coastlines. We estimate that by 2100 similar to 50% of the 7,000+ locations considered will experience the present-day 100-yr extreme-sea-level event at least once a year, even under 1.5 degrees C of warming, and often well before the end of the century. The tropics appear more sensitive than the Northern high latitudes, where some locations do not see this frequency change even for the highest global warming levels.

Automated summary

This study used a multimethod approach to describe changes in extreme sea levels driven by changes in mean sea level associated with global warming levels from 1.5 to 5 degrees C. The findings suggest that by 2100, over 50% of the locations considered will experience present-day 100-yr extreme-sea-level events at least once a year, even under 1.5 degrees C of global warming. The tropics appear to be more sensitive to these changes compared to Northern high latitudes.