New Research on Sea Level Rise

New research on sea level rise indicates that it could happen faster than previously thought, with major implications for coastal areas around the world. The Washington Post just published a long article about geologist Andrea Dutton and her research in the Seychelles, an island state in the Indian ocean that is one of the world's countries most at risk from sea level rise.  

To Andrea Dutton, a geologist at the University of Wisconsin at Madison, the Seychelles’ geologic singularity made it the perfect place to conduct research on ancient sea levels. The granite landmasses do not sink in the manner of atolls and volcanic islands, which subside as they drift away from the mantle plume that created them. The islands were also far enough from former ice sheets that they were less affected by changes in the Earth’s shape caused by ice pressing down on the crust.

“The Seychelles was really a serendipitous find in many ways,” Dutton said. The islands’ long-term stability made them ideal for comparing sea levels from ancient times to those seen today. If researchers found evidence of a reef on land that is now above water, they could be relatively certain it wasn’t because the land had moved — it was because the oceans had changed.

Her findings are troubling.

Alessio Rovere, a coastal geologist at Ca’ Foscari University of Venice, said Dutton’s findings add to a growing body of evidence that the Last Interglacial ice sheets didn’t melt simultaneously, causing sea levels to surge upward in multiple, sudden spurts.

“We can use it as a benchmark for what could happen in a future that is slightly warmer,” Rovere said, helping scientists develop better models of how modern ice sheets will behave.

But there is a key difference between the Last Interglacial and today, Dutton warned. Back then, the poles alternated warming, so melting from one ice sheet was buffered by the other. Now, the whole planet is warming at the same time as a result of human greenhouse gas emissions. Both Greenland and Antarctica are crumbling at once.

It's a highly readable article that explains the her research, what it shows, and why it's important. It's also beautifully illustrated, something I often ignore in newspaper articles, but in this case the photos and graphics enhance the article.