A study recently published on Nature found that sea level rise in the past two decades could have accelerated faster than previously thought, as consequence of climate change threatening coasts all over the world.

The authors, led by a researcher from Harvard University, revised the records from more than 600 tidal gauges worldwide and, after analyzing them using probabilistic techniques, found that readings from 1901-90 had over-estimated the rise in sea levels. The readings made after the 90s were found more accurate instead, and this resulted in a greater than expected acceleration of global mean sea level in the last decades. The new analysis suggests that the acceleration in the past two decades is 25 percent higher than previously thought.

The new study found that the 1901-90 rise averaged about 1.2 millimeters a year, while previous estimates were between 1.6 and 1.9 mm per year. The rate however leapt to 3 mm a year in the past two decades, apparently linked to a quickening thaw of ice.

Last year, the U.N.'s Intergovernmental Panel on Climate Change (IPCC) estimated the 1901-90 rate at 1.5 mm a year, a value somewhat in between the other estimates. The new findings will not influence the IPCC sea level projections for the future, since the estimates they make are not based on historical trends but take into account the various processes that influence the change in sea level.
The new study however confirms that the global sea level is rising, showing a sharp acceleration, and that the recent rates are the highest ever recorded.

The article is available online at the following link