Researchers estimate that in the past 30 years, close to 28 trillion metric tons of ice have melted away from the world’s sea ice, ice sheets, and glaciers. “It was a surprise to see such a large increase in just 30 years,” said co-author Thomas Slater, a glaciologist at Leeds University in the United Kingdon, reports Reuters.
Ice loss is relatively clear to those people depending on mountain glaciers for drinking water, or active sea ice to protect coastal homes from storms, but the melting of the world’s ice in far-flung places has grabbed the attention of researchers.
In Alaska, people are “keenly aware” of glacial ice loss, said geologist Gabriel Wolken with the Alaska Division of Geological and Geophysical Surveys. “You can see the changes with the human eye.”
The authors believe the study may be the first truly comprehensive report that takes into account both the Greenland and Antarctic ice sheets, Arctic and Antarctic sea ice, and mountain glaciers around the globe.
The British scientists used a variety of resources to come to their conclusions, including satellite measurements from 1994–2017, computer modeling and ground measurements, and on-site observations. The findings show that ice is steadily disappearing across much of the world, and a majority of the losses are driven by climate change.
The earth has over 215 thousand glaciers worldwide, according to a 2017 report from the Randolph Glacier Inventory. Their retreat has accounted for 21 percent of global sea-level rise between 1993 and 2017, write the authors.
Sea ice typically covers polar regions, although its thickness and extent vary seasonally. However, the loss of sea ice due to long-term changes in Earth’s climate was reported in a study this past September by scientists at the University of Alaska, Fairbanks.
According to the new study, “Sea ice plays a key role in the freshwater and energy budgets of the polar regions, impacts the marine ecosystem, and regulates the absorption of solar radiation in summer. Furthermore, sea ice loss could influence oceanic and atmospheric circulation and affect weather patterns in the mid-latitudes.”
The bottom line? The researchers note that “there can be little doubt that the vast majority of Earth’s ice loss is a direct consequence of climate warming.”
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