Melting sea ice would cause sea levels to rise by 'hair's breadth'
Melting icebergs are causing sea levels to rise, scientists have discovered, but only by a hair's breadth every year.
By Louise Gray, Environment Correspondent
Published: 5:00PM BST 28 Apr 2010
Researchers at the University of Leeds calculate that around 1.5 million Titanic-sized icebergs each year are melting into the sea every year in the Arctic and Antarctic. This is causing sea level to rise by just 49 micrometers per year - around a hair's breadth.
At that rate it would take 200 years for the oceans to rise by 1cm as a result of melting sea ice. If all the floating ice in the world melted it would cause sea levels to rise by just 4cm. In comparison if all the ice on land melted it would cause a rise of 70m. Sea levels will also rise as the oceans get warmer because of thermal expansion.
But Professor Andrew Shepherd, one of the authors of the study published in Geophysical Research Letters, said the tiny rise caused by melting ice was still significant.
He said it will be important to factor in the small changes caused by melting sea ice in judging sea level rise in the future, especially if global warming accelerates. Melting ice caps also accelerate climate change as seawater absorbs more sunlight, therefore it will warm quicker than when the sea is covered in ice.
"Over recent decades there have been dramatic reductions in the quantity of Earth's floating ice, including collapses of Antarctic ice shelves and the retreat of Arctic sea ice," he said.
"These changes have had major impacts on regional climate and, because oceans are expected to warm considerably over the course of the 21st century, the melting of floating ice should be considered in future assessments of sea level rise."