Earth is losing ice faster today than in mid-1990s, study finds

ANCHORAGE, Alaska (Reuters) – Earth’s ice is melting faster today than in the mid-1990s, new research suggests, as climate change pushes global temperatures higher and higher.

In total, about 28 trillion tonnes of ice have melted from the world’s sea ice, ice caps and glaciers since the mid-1990s. Each year, the rate of melting is now about 57% faster than it is. Three decades ago, scientists report in a study published Monday in The Cryosphere.

“It was a surprise to see such an increase in just 30 years,” said co-author Thomas Slater, a glaciologist at the University of Leeds in Britain.

While the situation is clear for those who depend on mountain glaciers for drinking water, or who rely on winter sea ice to protect coastal homes from storms, the world’s melting ice has started to attract attention away from frozen areas, Slater noted.

As well as being captivated by the beauty of the polar regions, “people recognize 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 – over Antarctica, Greenland, and mountain glaciers – added enough water to the ocean over the three-decade period to raise the global average sea level by 3, 2 inches. Ice loss from mountain glaciers accounted for 22% of total annual ice loss, which is remarkable given that it only accounts for about 1% of all land ice at the top of land, said Slater.

Across the Arctic, sea ice is also shrinking to reach new summer lows. Last year saw the second-lowest extent of sea ice in more than 40 years of satellite monitoring. When sea ice disappears, it exposes dark water that absorbs solar radiation, rather than pushing it back out of the atmosphere. This phenomenon, known as arctic amplification, further increases regional temperatures.

Global atmospheric temperature has risen by about 1.1 degrees Celsius since pre-industrial times. But in the Arctic, the rate of warming has been more than double the global average over the past 30 years.

Using satellite data from 1994 to 2017, site measurements and some computer simulations, the team of British scientists calculated that the world was losing an average of 0.8 trillion tonnes of ice per year in the 1990s. , but about 1.2 trillion tonnes per year in recent years. .

Calculating even a total estimate of the loss of ice from the world’s glaciers, ice caps and polar seas is “a really interesting approach, and one which is in fact very necessary,” said geologist Gabriel Wolken of the Alaska Geological and Geophysical Survey Division. Wolken was a co-author of the Arctic Bulletin 2020 published in December, but was not involved in the new study.

In Alaska, people are “well aware” of the loss of glacial ice, Wolken said. “You can see the changes with the human eye.”

Researcher Julienne Stroeve of the National Snow and Ice Data Center in Boulder, Colorado noted that the study did not include snow cover on land, “which also has a strong albedo return,” referring to a measurement of the reflection of 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 considerable changes in recent decades.”