Science

Rate Of Sea Level Rise Accelerated Over Last 20 Years

Scientists previously thought that the sea level rise had slowed down, but new research contradicts previous findings. Climate models show that sea levels may be rising at a faster rate than before as ice sheets in West Antarctica and Greenland continue to melt, writes Karl Mathiesen for The Guardian.

Rate Of Sea Level Rise Accelerated Over Last 20 Years

New research corroborates IPCC model

“The thing that was really puzzling us was that the last decade of sea level rise was marginally slower, ever so subtly slower, than the decade before it,” said study lead author Dr Christopher Watson from the University of Tasmania.

The team discovered that existing records of sea level rise were too high, and the error carried through into their calculations. The new rate is consistent with the modelling carried out by the Intergovernmental Panel on Climate Change (IPCC), the UN climate science organization.

“We see acceleration, and what I find striking about that is the fact that it’s consistent with the projections of sea level rise published by the IPCC,” said Watson. “Sea level rise is getting faster. We know it’s been getting faster over the last two decades than its been over the 20th century and its getting faster again.”

Difficult to measure accurately

Scientists measure sea level rise using a combination of tide gauges place around the world’s coastlines, and altimetric satellites. However both sets of data are imperfect. The land is constantly shifting and the satellite equipment has lost some of its accuracy since it was first put into orbit in 1993.

Watson’s team compared the two data sets in order to improve overall accuracy. The new research says that the rate of sea level rise is between 2.6 and 2.9 mm per year, while the IPCC report from 2013 gave a rate of 3.2 mm per year.

However Watson does not wish to downplay the importance of the issue, he claims that he has to “come back to the data” when drawing his conclusions. He says that the fact that the rate is increasing is of huge importance, and should be of huge concern to those who live in coastal areas.

The IPCC report claimed that sea levels could rise 28-98 cm by 2100, dependent on how much carbon the human race emits.