The world’s ice is melting so fast that sea level rise predictions cannot keep up. The ice melting is faster today than in the mid-1990s, new research suggests, as climate crisis nudges global temperatures ever higher.
In the 1990s, the Earth’s ice was melting at a rate of about 760 billion tons per year. That has surged 60 percent to an average of 1.2 trillion tons per year in the 2010s, a study published Monday in the journal The Cryosphere estimates.
Another study published earlier this month in Science Advances makes clear, the problem is feeding into itself.
Climate change is largely responsible for the huge ice melt surge, the Cryosphere study reports.
About three percent of all the energy trapped within the Earth’s systems because of climate change has gone toward that ice melt, the study estimates.
“That’s like more than 10,000 ‘Back to the Future’ lightning strikes per second of energy melting ice around-the-clock since 1994,” William Colgan, an ice-sheet expert at the Geological Survey of Denmark and Greenland, told The Washington Post. “That is just a bonkers amount of energy.”
The Earth’s ice is melting around 57% faster than it was three decades ago according to research published in The Cryosphere’.
Altogether, an estimated 28 trillion metric tons of ice have melted away from the world’s sea ice, ice sheets and glaciers since the mid-1990s. Annually, the melt rate is now about 57 percent faster than it was three decades ago, scientists report in a study published Monday in The Cryosphere.
Climate change not only melts ice sheets on land, but also warms ocean waters to melt glaciers from the bottom up as well. Past sea level rise projections have failed to account for this glacial undercutting by “at least a factor of 2” the Science Advances study found. “Together, the two studies present a worrying picture,” the Post writes.
The first study found “the ice sheets are now following the worst-case climate warming scenarios set out by the Intergovernmental Panel on Climate Change,” study author Thomas Slater said in a statement.
But the second reveals that the panel’s sea level projections, which were already criticized as too conservative, may have underestimated the role of glacial undercutting in accelerating ice melt even more.
“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 Britain.
While the situation is clear to those depending on mountain glaciers for drinking water, or relying on winter sea ice to protect coastal homes from storms, the world’s ice melt has begun to grab attention far from frozen regions, Slater noted.
Aside from being captivated by the beauty of polar regions, “people do recognize that, although the ice is far away, the effects of the melting 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 time period to raise the average global sea level by 3.5 centimeters. Ice loss from mountain glaciers accounted for 22 percent of the annual ice loss totals, which is noteworthy considering it accounts for only about 1 percent of all land ice atop land, Slater said.
Across the Arctic, sea ice is also shrinking to new summertime lows. Last year saw the second-lowest sea ice extent in more than 40 years of satellite monitoring. As sea ice vanishes, it exposes dark water, which absorbs solar radiation, rather than reflecting it back out of the atmosphere. This phenomenon, known as Arctic amplification, boosts regional temperatures even further.
The global atmospheric temperature has risen by about 1.1 degrees Celsius since pre-industrial times. But in the Arctic, the warming rate has been more than twice the global average in the last 30 years.
Using 1994–2017 satellite data, site measurements and some computer simulations, the team of British scientists calculated that the world was losing an average of 0.8 trillion metric tons of ice per year in the 1990s, but about 1.2 trillion metric tons annually in recent years.
Calculating even an estimated ice loss total from the world’s glaciers, ice sheets and polar seas is “a really interesting approach, and one that’s actually quite needed,” said geologist Gabriel Wolken with the Alaska Division of Geological and Geophysical Surveys. Wolken was a co-author on the 2020 Arctic Report Card released in December, but was not involved with the new study.
In Alaska, people are “keenly aware” of glacial ice loss, 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 the study had not included snow cover over land, “which also has a strong albedo feedback”, referring to a measure of how reflective a surface is.
The research also did not consider river or lake ice or permafrost, except to say, “These elements of the cryosphere have also experienced considerable change over recent decades.”