Why Is Greenland Covered In Ice? Changes In Carbon Dioxide Levels Explain Transition

August 28, 2008

There have been many reports in the media about the effects of global warming on the Greenland ice-sheet, but there is still great uncertainty as to why there is an ice-sheet there at all.

Reporting today (28 August) in the journal Nature, scientists at the University of Bristol and the University of Leeds show that only changes in atmospheric carbon dioxide are able to explain the transition from the mostly ice-free Greenland of three million years ago, to the ice-covered Greenland of today.

Understanding why the ice formed on Greenland three million years ago will help understand the possible response of the ice sheet to future climate change.

Dr Dan Lunt from the University of Bristol and funded by the British Antarctic Survey, explained: "Evidence shows that around three million years ago there was an increase in the amount of rock and debris deposited on the ocean floor around Greenland. These rocks could not have got there until icebergs started to form and could transport them, indicating that large amounts of ice on Greenland only began to form about three million years ago.

Computer models show that while (tectonic) uplift of the Rocky Mountains may have contributed to increased ice cover on Greenland, this change was small in comparison with the ice sheet caused by a decrease in carbon dioxide. (Credit: Dan Lunt, University of Bristol)

More of the story,
click image

Posted in Earth Sciences, Science and Technology