High-water mark

We know little about the behaviour of ice sheets. <br>© Getty Images <br>

Bleak forecast for sea level in 2100.

Sea level could rise by up to 30 centimetres over the next century, a new estimate predicts. That’s almost twice as much as the Intergovernmental Panel on Climate Change (IPCC) projected last year.

“My grandchildren will almost certainly be affected,” says Mark Meier of the University of Colorado, Boulder, who made the revised estimate. Such a rise could push shorelines back by 30 metres, he said, flooding coasts and submerging islands.

Swelling seawater and melting ice exceed the forecasts of current global-warming models, baffling scientists. Meier believes that some areas become increasingly temperature-sensitive as it gets warmer. His calculations, unlike the IPCC’s, take into account melting glaciers in Alaska, Antarctica and Greenland.

The discrepancy highlights our ignorance of ice sheets and glaciers, researchers warned the meeting of the American Association for the Advancement of Science in Boston. “We are very data-poor,” Meier admits.

Cost-cutting and political change over the past 20 years have closed many vital monitoring stations, for example in remote areas of Russia and Canada, leaving researchers scrabbling for data. The accuracy of both forecasts remains moot.

Climate monitoring “will never be as good as we had or as good as we want”, said Mark Serreze, also of the University of Colorado. Pieces of the Antarctic ice shelf the size of Rhode Island have splintered and disappeared over the past 50 years, he told the meeting. This allows glaciers to dump more melt into the ocean.

Whether greenhouse-gas emissions are to blame for the thaw is unclear. But no one is ruling it out. “Ice shelves have retreated and advanced in the past,” explained Colorado’s Ted Scambos. We might have passed some threshold that means there’s no going back this time. “But I wouldn’t want to say yes or no on that,” he cautioned.

Monitoring with satellites and planes will hopefully plug some knowledge gaps. Keith Echelmeyer of the University of Alaska in Fairbanks has fitted his light aircraft with a laser altimeter and a global positioning system. Comparing measurements of ground level with old topography maps can reveal changes due to melting.

Media Contact

SARA ABDULLA © Nature News Service

Alle Nachrichten aus der Kategorie: Earth Sciences

Earth Sciences (also referred to as Geosciences), which deals with basic issues surrounding our planet, plays a vital role in the area of energy and raw materials supply.

Earth Sciences comprises subjects such as geology, geography, geological informatics, paleontology, mineralogy, petrography, crystallography, geophysics, geodesy, glaciology, cartography, photogrammetry, meteorology and seismology, early-warning systems, earthquake research and polar research.

Zurück zur Startseite

Kommentare (0)

Schreib Kommentar

Neueste Beiträge

An artificial cell on a chip

Researchers at the University of Basel have developed a precisely controllable system for mimicking biochemical reaction cascades in cells. Using microfluidic technology, they produce miniature polymeric reaction containers equipped with…

Specific and rapid expansion of blood vessels

Nature Communications: KIT researchers identify a new mechanism to control endothelial cell size and arterial caliber – basis for better treatment of heart infarct and stroke. Upon a heart infarct…

Climate change drives plants to extinction in the Black Forest in Germany

Climate change is leaving its mark on the bog complexes of the German Black Forest. Due to rising temperatures and longer dry periods, two plant species have already gone extinct…

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close