Ocean Warming Rate Underestimated
To date, research on the effects of climate change has underestimated the contribution of seawater expansion to sea level rise due to warming of the oceans. A team of researchers at the University of Bonn has now investigated, using satellite data, that this effect was almost twice as large over the past twelve years than previously assumed. That may result in, for example, significantly increased risks of storm surges. The scientists are presenting their findings in the renowned scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).
In principle, water in the oceans acts like a mercury thermometer: when the temperature goes up, the liquid expands and climbs up the little tube. Since the world's oceans are similarly locked in between the continents, their levels also rise when they heat up due to rising temperatures. "In the deeper parts of the ocean, even a small amount of warming is enough to create a significant rise in sea level," says Dr.-Ing. Roelof Rietbroek from the Institute of Geodesy and Geoinformation at the University of Bonn. An increase of several millimeters a year, he says, is not rare in deep-sea zones.