Ocean Levels in the Last Two Decades May have Climbed Higher than Previously Thought

Contrary to existing notion, climate change may have caused ocean levels to rise higher than previously thought in the last two decades.

According to Reuters, a new report published in the journal Nature claims that the rise in ocean levels between 1901 and 1990 may have been overestimated, resulting in underestimation of the rise in levels across the globe during the last two decades. The report claims that sea levels rose by 1.2 mm on average per year between 1901 and 1990 as against the present estimate of 1.5 mm per year.

"What this paper shows is that sea-level acceleration over the past century has been greater than had been estimated by others. It's a larger problem than we initially thought," Carling Ray at Harvard University told Harvard Gazette.

"Scientists now believe that most of the world's ice sheets and mountain glaciers are melting in response to rising temperatures. Melting ice sheets cause global mean sea level to rise. Understanding this contribution is critical in a warming world," he added.

The increase post-1990 as per present estimates is around 3 mm per year which researchers say is underestimated. They suggest that the actual number would be at least 25 percent higher.

The paper calls for recalibration of global models even as it stresses the importance of historical records. However researchers said that scientific community is in agreement that there has been an steep rise on ocean levels due to various factors including global warming and the effects of the last ice age.