|By Le Williams | 3 years ago|
Scientists have reported a significant change in the measurement of three major Antarctic ice sheets as global temperatures increase and sea levels rise. Notably, the East Antarctic Ice Sheet remains the largest concern to sea-level rise, in addition to melting glaciers within the proximity.
In the journal Nature, a team of scientists report the techniques used to determine their findings. Nature explains that the researchers integrate ultra-sensitive analytical measurements that have helped to reveal the history of other ice sheets. Researchers found that the East Antarctic Ice Sheet did not retreat significantly over land during the warm Pliocene epoch, approximately 5.3 to 2.6 million years ago, when atmospheric carbon dioxide concentrations were similar to today’s levels.
“Based on this evidence from the Pliocene, today’s current carbon dioxide levels are not enough to destabilize the land-based ice on the Antarctic continent,” said Boston College Assistant Professor of Earth and Environmental Science Jeremy Shakun, a lead author of the report. “This does not mean that at current atmospheric carbon dioxide levels, Antarctica won’t contribute to sea-level rise. Marine-based ice very well could and in fact is already starting to—and that alone holds an estimated 65 feet of sea-level rise. We’re saying that the terrestrial segment of the ice sheet is resilient at current carbon dioxide levels.”
Estimates of sea-level rise during the Pliocene have varied, from 20 feet to more than 130 feet higher than today. The upper end of this range would imply that much of the ice on the planet melted, which all together holds enough water to raise sea levels by over 200 feet.
If the land-based East Antarctic Ice Sheet was stable during the Pliocene, however, as Shakun and colleagues suggest, the Pliocene total could have been at most about 100 feet.