ANCHORAGE, Alaska (Reuters) – Earth’s ice is melting faster today than in the mid-1990s, new research suggests, as climate change drives global temperatures higher and higher.
In total, an estimated 28 trillion tons of ice have melted away from the world’s sea ice, ice sheets and glaciers since the mid-1990s. Annually, the melting rate is now about 57 percent faster than it was three decades ago, scientists report in a study published Monday in the journal The Cryosphere.
“It was a surprise to see such a big increase in just 30 years,” said study co-author Thomas Slater, a glaciologist at Leeds University in the UK.
While the situation is clear to those who rely on mountain glaciers for drinking water, or rely on winter sea ice to protect coastal homes from storms, the melting ice world is beginning to attract attention far from frozen regions, Slater noted.
In addition to being fascinated by the beauty of polar regions, “people recognize that although the ice is far away, the effects of the melting will be felt by them,” he said.
Melting of land ice – in Antarctica, Greenland and mountain glaciers – added enough water to the ocean over the three decades to raise the average global sea level by 3.5 centimeters. Ice loss from mountain glaciers accounted for 22 percent of annual ice loss totals, which is remarkable given that it makes up only about 1 percent of all land ice on land, Slater said.
Across the Arctic, sea ice is also shrinking to new lows in summer. Last year there was the second lowest sea ice in more than 40 years of satellite monitoring. As sea ice dissipates, it exposes dark water that absorbs solar radiation instead of reflecting it off the atmosphere. This phenomenon, known as Arctic strengthening, increases regional temperatures even further.
The global atmospheric temperature has increased by about 1.1 degrees Celsius since pre-industrial times. But in the Arctic, warming in the last 30 years has been more than twice the global average.
Using satellite data from 1994–2017, location measurements and some computer simulations, the team of British scientists calculated that the world lost an average of 0.8 trillion metric tons of ice per year in the 1990s, but about 1.2 trillion metric tons in recent years per year. .
Calculating even an estimated total ice loss from glaciers, ice sheets, and polar seas in the world is “a very interesting approach, and one that is actually very necessary,” said geologist Gabriel Clouds of the Alaska Division of Geological and Geophysical Surveys. Clouds co-authored the 2020 Arctic Report Card released in December, but was not involved in the new research.
In Alaska, people are “keenly aware” of the loss of ice ice, Wolken said. “You can see the changes with the human eye.”
Research scientist Julienne Stroeve of the National Snow and Ice Data Center in Boulder, Colorado, noted that the study did not include land snow cover, “which also has strong albedo feedback,” referring to a measure of how reflective a surface is.
The study also did not take river or lake ice or permafrost into account, except that “these elements of the cryosphere have also undergone significant changes in recent decades.”
Reporting by Yereth Rosen; Edited by Katy Daigle and Philippa Fletcher