Global sea levels have risen significantly faster than previously thought in the past two decades. It’s the latest sign of how climate change is threatening coasts around the world. A new study published by scientists at Harvard and Rutgers University suggests that climate change is having far greater impact on rising sea levels. Researchers found that global sea levels have risen at twice the estimated rate in the last two decades.
The rise has accelerated
Findings of the study have raised questions about the accuracy of forecasts of the 21st century. Harvard and Rutgers scientists reassessed records from over 600 tidal gauges. They found that the rise in sea levels between 1901 and 1990 was overestimated, but the acceleration from 1990 had been vastly underestimated. Scientists said that earlier readings were skewed or incomplete.
Findings of the study were published in the January 14 issue of the journal Nature. Carling Hay, the lead author of the study, said that the acceleration in the sea level rise over the past two decades was 25% higher than previously thought. Between 1901 and 1990, experts predicted a rise of between 1.5mm and 1.8mm, but the actual figure was only 1.2mm.
Sea levels rising by 3mm every year
Since 1990, the sea levels have risen by 3mm per year. The sea level rise is caused by several factors such as global warming, thaw of ice, and changes in circulation. The recent jump has been linked to quickening thaw of ice. Harvard scientists said that new findings could affect the forecast of future rate of the sea level rise, especially those projections that are based on historical trends, reports Reuters.
To get the more accurate figures, scientists analyzed the sea level “fingerprints” that model the physics involved in the changes. They looked at all the available records, and added in the rate that world’s oceans are changing due to thermal expansion. The result is global mean sea-level change. Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research said findings confirmed that sea levels are rising and the “rise has accelerated.”