ANKERAGE, Alaska (Reuters) – Earth’s ice is melting faster today than in the mid-1990s, according to new research as climate change pushes global temperatures ever higher.
A total of 28 billion trillion tons of ice has 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 huge increase in just thirty years,” said co-author Thomas Slater, a glacier at Leeds University in Britain.
Although the situation is clear for those who depend on mountain glaciers to drink water, or to rely on winter sea ice to protect coastal homes from storms, the world’s ice melt has caught the attention of frozen regions far away. Slater said.
Aside from being enchanted by the beauty of polar regions, “people do realize that even though the ice is far away, the effects of the melt will be felt by them,” he said.
The melting of land ice – on Antarctica, Greenland and mountain glaciers – added enough water to the ocean during the three-decade period to raise the average world sea level by 3.5 centimeters. Ice loss from mountain glaciers accounted for 22 percent of the annual total ice loss total, which is remarkable since it accounts for only about 1 percent of all land ice on top of the land, Slater said.
Across the Arctic, sea ice is also shrinking to new summer lows. Last year was the second lowest sea ice magnitude in more than 40 years of satellite monitoring. As sea ice disappears, it exposes dark water that absorbs solar radiation, rather than reflecting it back out of the atmosphere. This phenomenon, known as Arctic amplification, raises the local temperature even further.
The global atmospheric temperature has risen by about 1.1 degrees Celsius since pre-industrial times. But in the Arctic, warming has been more than twice the world average over the past thirty years.
Using satellite data from 1994–2017, site measurements and some computer simulations, the team of British scientists calculated that the world lost an average of 0.8 trillion tons of ice per year in the 1990s, but in recent years about 1.2 trillion tons per year. .
Calculating even a total ice loss from glaciers, ice sheets and polar seas is a very interesting approach, and one that is actually very much needed, ‘said geologist Gabriel Wolken with the Geological and Geophysical Surveys Division in Alaska. Clouds co-authored the 2020 Arctic Report Card released in December, but was not involved in the new study.
In Alaska, people are ‘very aware’ of ice loss, Wolken says. “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 snow cover over land, ‘which also has strong albedo feedback’, citing some of the reflective is a surface.
The research also did not take into account river or lake ice or permafrost, except to say that ‘these elements of the cryosphere have also undergone significant change in recent decades.’
Reporting by Yereth Rosen; Edited by Katy Daigle and Philippa Fletcher