But what experts have little information about is how these major glaciers have changed in the past, especially centuries before the existence of satellite recordings. Understanding how glaciers have responded to climate change will affect scientists’ predictions about how they might react to future warming.
Researchers have found that Greenland’s glaciers are more sensitive to climatic conditions, and have lost ice in the late 19th and early 20th centuries. With the planet – especially the Arctic – expected to heat up even more this century, scientists have found that their findings show that even the worst predictions of ice loss in Greenland could be made.
David Holland, professor of mathematics and environmental science at New York University and co-author of the study, said the team’s findings show that the Arctic is “subject to a couple of punches in relation to the loss of its land and sea ice.” “
Using historical photographs of the glaciers of Jakobshawn, Helheim and Kangarluசwak, the team calculated snow loss from 1880 to 2012. They estimated that the amount of ice lost from all three glaciers had risen by 8.1 millimeters above sea level. According to Hollande, although the three glaciers are important in their own right, they also act as substitutes for the majority of other store glaciers in Greenland, giving scientists an overview of how the entire ice sheet works.
Greenland’s ice is a dynamic place that is constantly changing and moving. If we think of the interior of the iceberg as a mountain lake, Moon says, the icebergs of this store are the streams that flow out of the lake, taking the ice from it and in many cases into the sea. When the ice breaks off from the iceberg and descends into the sea, it raises the sea level.
“These three glaciers are one of the fastest moving in the Greenland. Twila Moon, not involved in the study.
Glaciers have enough ice to raise global sea levels by about 1.3 meters.
Ice loss over time is driven by natural changes in air and sea currents, and Holland says they melt when hot water comes close to glaciers. But man-made warming changes the climate and changes how air and sea interact with ice, thus affecting the extent of ice loss.
The team found that the ice loss rates for the Jakobshawn Glacier in the early 1900s were comparable to the largest loss rates seen today, and that the ice loss between the Kangaroozook Glacier between 1880 and 1930 was actually larger than it is today.
This shows that glaciers are losing more ice at a time when global temperatures are lower than they are now.
The planet could heat up to 3.7 degrees Celsius (6.66 degrees Fahrenheit) by the end of this century, in the worst case scenario where humans will continue to raise the concentrations of these heat-trapping gases in the atmosphere.
If glaciers had already suffered major ice losses when atmospheric and ocean temperatures were low – and high emissions were set to make the planet even warmer in the future – scientists could underestimate how much Greenland would lose by the end of the century if their findings were used as models to predict future ice loss.
It may also affect current forecasts of sea level rise.
“When it comes to the pace of change in Greenland, with snow everywhere in the world, we are already on five alert levels,” Moon said. “This paper is just another piece of paper in that terrible pile. They say there are very drastic changes. They are happening very quickly. We need to act quickly so we can try to reduce the rate of change in the future.”
In the study, scientists said that underestimating ice loss was “not just for these three glaciers” and that it was important for samples to capture rapid glacial retreat as a result of man – induced warming in our oceans and atmosphere. “Because they are the primary driver of mass loss.”
The team hopes that their findings on how glaciers are sensitive to climate change will help increase the reliability of future forecasts for snow loss.
“The Arctic is losing ice. When you look at the last century in detail, you see periods of high loss and low loss, but always loss,” Holland said. “As increased warming is expected to continue in the future, severe snow loss is likely to hit coastal cities around the world.”
CNN ‘s Ivana Kottasova contributed to the report.