But experts who have little information on how these important glaciers have changed in the past, especially centuries before the existence of satellite records. Understanding how glaciers have reacted to past climate changes can influence scientists’ estimates of how they may react to future temperatures.
Researchers have found that Greenland’s glaciers are highly sensitive to weather conditions, and have lost ice at a rate of more or less in the late 19th and early 20th centuries. With the planet and especially the Arctic expected to get warmer this century, scientists have warned their findings that the loss of ice on Greenland could exceed even the worst case estimate.
David Holland, a professor of mathematics and environmental sciences at New York University and co-author of the study, said the team’s findings show that the Arctic is taking one-two punches in light of its land and sea ice damage. Warming covers the world. “
Using historical photographs of the Jakobshavan, Helhem and Kanjarlusuk glaciers, the team calculated ice losses between 1880 and 2012. They estimate that the loss of ice from these three glaciers alone has increased by 8.1 millimeters above sea level. Holland said that while all three glaciers are important in their own way, they also serve as proxies for most of Greenland’s other outlet glaciers, giving scientists a glimpse of how a whole ice sheet behaves.
Greenland’s ice sheet is a dynamic place that is constantly migrating. If we think of the interior of the ice sheet as a mountain lake, the moon says, these outlets are the rivers flowing out of the glaciers lake, which take the ice away from there and in many cases, into the ocean. When ice breaks from a glacier and falls into the ocean, it raises the sea level.
“These three glaciers are the fastest moving in Greenland. When we think of these glaciers acting as conveyor belts around Greenland, these are some of the fastest, largest conveyor belts on a sheet of ice.” “We were not involved in the study,” said Twilla Moon, deputy lead scientist at the National Snow and Ice Data Center in Boulder, Colorado.
Glaciers have enough ice to raise global sea levels by about 1.3 meters.
Overland says the loss of ice over time is driven by natural shifts in wind and ocean currents, and when hot water comes close to glaciers, it melts, Holland says. But due to human-warming the atmosphere has changed and it is changing how the wind and the sea interact with the ice sheet, and therefore affect the extent of ice damage.
The team found that the rate of ice loss for the Jacobsvan Glacier in the early 1900s was much higher than the massive rate seen today, and for the Kangralsuwak Glacier, the ice loss between 1880 and 1930 was actually higher than present.
This is significant because it shows that glaciers were losing large amounts of ice at a time when global temperatures were lower than at present.
In a bad situation in which humans continue to increase the concentration of heat-dissipating gases in the atmosphere, by the end of this century the planet could have warmed by 7.7 degrees Celsius (.6..66 degrees Fahrenheit).
Glaciers have already suffered massive ice losses when atmospheric and ocean temperatures are low – and the planet is preparing to warm up even under high-emission futures – scientists say in their findings, the models used to predict future ice losses mean Can happen. One can only underestimate how little Greenland will be by the end of the century.
Which may also affect additional current projections of the sea surface.
“I think when the pace of change in Greenland comes and snow falls everywhere in the world, we’re already in a five-alarm state,” Moon said. “And this paper is one more piece of paper in that monster pile that says this is a really serious change, it’s happening very quickly and we need to take action as soon as possible so that we can try to reduce the rate of change in the future.”
Scientists in the study said the possibility of ignoring the potential for ice damage was “not limited to just these three glaciers”, and it was important that models quickly gain glacier isolation as a result of the human-induced warming of our oceans and atmosphere. “Because they are the primary driver of massive damage.”
The team hopes that the findings on how glaciers are sensitive to climate change will help increase the reliability of future predictions of ice damage.
“The Arctic ice is losing, and when you look in more detail over the last century, you’ll see periods of more damage and less damage, but there are always losses,” Holland said. “Increasing ice damage can be expected with potentially serious negative consequences for coastal cities around the world, with rising warming expected to continue in the future.”
CNN’s Ivana Kottasova contributed to the report.
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