Study: Warming Accelerates U.S. East Coast Sea Level Rise

According to a new study to be published online by the Proceedings of the National Academy of Sciences this week, sea level is rising faster along the U.S. East Coast than it has for at least 2,000 years. The study concludes that the ocean began rising an average of 2.1 millimeters per year some time between 1865 and 1892 and has not stopped. The current rate of sea level rise is about 3.2 mm per year. Co-author Benjamin Horton, a coastal geologist at the University of Pennsylvania, argues that the trend is a direct consequence of increasing temperatures. According to the research, temperatures and sea levels have been “rising and falling in lockstep” for at least the last 1,000 years. Scientists have reliable measurements of recent sea level rise from a combination of tide gauges and satellites, but to determine historical conditions, researchers examined sediment samples from North Carolina salt marshes. The steady accumulation of sediment (as the marshes sink and are rebuilt by tides washing in new sediment) traps foraminifera, plant matter and other substances that form a natural record of sea level rise. The scientists began decoding that record by mapping the distribution of different foraminifera species at 10 North Carolina marsh sites.

The full study can be accessed online, here.