Changes in the speed that ice travels in more than 200 outlet glaciers indicates that Greenland's contribution to rising sea level in the 21st century could be significantly less than the upper limits some scientists thought possible.
The finding comes from a paper funded by the National Science Foundation (NSF) and NASA and published in today's journal Science.
While the study indicates that a melting Greenland's contributions to rising sea levels could be less than expected, researchers concede that more work needs to be done before any definitive trend can be identified.
Studies like this one are designed to examine more closely and in greater detail what is actually happening with the ice sheets, often using newer and more precise tools and thereby better defining the parameters that scientists use to make predictions, such as the upper limits of sea-level rise.
"This study provides more evidence that the rate at which these glaciers can dump ice into the ocean is indeed limited," said Ian Howat, assistant professor of Earth sciences and member of the Byrd Polar Research Center at Ohio State University, a co-author on the paper. "What remains to be seen is how long the acceleration will continue--but it appears that our worst-case scenarios aren't likely."
The fate of the Earth's ice sheets and their potential contributions to sea-level rise as the globe warms are among the major scientific uncertainties cited in the Fourth Assessment of the Intergovernmental Panel on Climate Change (IPCC). This is in part because the Greenland and Antarctic ice sheets have historically been, and in large measure continue to be, relatively sparsely monitored, as compared to other parts of the globe.
The faster the glaciers move, the more ice and melt water they release into the ocean.
In previous studies, scientists trying to understand the contribution of melting ice to rising sea level in a warming worl
|Contact: Deborah Wing|
National Science Foundation