According to two new studies, the ice in Antarctica is melting at record levels, and the subsequent sea rises can have catastrophic consequences for cities around the world.
Andrew Shepherd from the University of Leeds in the United Kingdom and Erik Ivins from NASA's Jet Propulsion Laboratory (JPL) led a group of 84 scientists from 44 worldwide organizations in the research that gives us the most complete picture to date of the changes going on with the Antarctic ice sheet.
"Understanding the causes of recent catastrophic ice shelf disintegrations is a crucial step towards improving coupled models of the Antarctic Ice Sheet and predicting its future state and contribution to sea-level rise", the authors write in their paper. As the ice shelves thin and weaken, they provide less resistance to ice flow from the continent to the sea.
"The increasing mass loss that they're finding is really worrying, particularly looking at the West Antarctic, the area that's changing most rapidly and it's the area that we're most anxious about, because it's below sea level", said Christine Dow, a glaciologist at the University of Waterloo in Canada who was not involved in the research.
Until now, scientists thought the retreat of the West Antarctic Ice Sheet was continuous.
We have long suspected that changes in Earth's climate will affect the polar ice sheets.
The findings were published today in the journal Nature. Since 1992, it lost 3 trillion tons of ice, losing some of the West Antarctic Ice Sheet and Antarctic Peninsula. It alone is responsible for between 5-10% of global sea-level rise.
Melting of Antarctica is speeding up, worrying scientists
A trillion-tonne iceberg, one of the biggest on record and twice the size of the ACT, snapped off the Larsen C West Antarctic ice shelf in July past year. "This information could have an impact on our projected timelines for ice shelf collapse and resulting sea level rise due to climate change".
Likewise, the fact that some ice on the southern continent was stable in a warming climate does not signal that Antarctica can somehow backstop the impact of climate change, they cautioned. Ocean acidification would harm the shells of some sea creatures and the number of invasive species would increase tenfold.
Covering twice the area of the continental United States, Antarctica is blanketed by enough ice pack to lift global oceans by almost 60 metres (210 feet). None." The Times explains: "Dale said that global carbon emissions from energy had risen by 1.6% last year, after three years of "little or no growth".
"We can not count on East Antarctica to be the quiet player, and we start to observe change there in some sectors that have potential and they're vulnerable", said Velicogna. By comparison, the areas of the Antarctic continent, Australia and the U.S. are about 14, 7.7 and 9.8 million square kilometres, respectively.
By century's end, sea level - compared to a pre-industrial benchmark - could increase from a few dozen centimetres to a metre or more, depending in part on efforts to curb greenhouse gas emissions. This week's issue of Nature features several other reports on Antarctica and its future.
"The kinds of changes that we see today, if they were not to increase much more. then maybe we're talking about something that is manageable for coastal stakeholders", Rob DeConto, a researcher not involved in the study, told The Washington Post.
Forces that are driving these changes are not going to get any better in a warming climate.More news: Messi penalty saved as dominant Argentina held by Iceland