You may have recently seen the jarring photo of a sled team running through water in Greenland under the glistening Sun. Or the equally startling report that the island lost more than 2 gigatons of ice in a single day last week.
However, it looks like these are just the beginnings of the earthshaking changes Greenland is about to undergo.
Geophysicists have used satellite data and computer models to predict the long-term effects of warming global temperatures on Greenland’s melting ice sheet, reporting their findings in the journal Science Advances this week.
In sum, it ain’t good. If current trends continue, Greenland's ice sheet will be almost iceless by the year 3000. Even in a best-case scenario, in which we dramatically cut emissions by the end of this century, ice loss in Greenland is expected to be around 8 to 25 percent and directly result in 1.8 meters (6 feet) of sea level rise within the millennium.
Even in the shorter term, the picture is pretty grim. Greenland's ice sheets are forecasted to contribute up to 160 centimeters (63 inches) to global sea level rise, at least 80 percent more than previous estimates, which forecasted up to 89 centimeters (35 inches) of sea level rise.
“What we are doing right now in terms of emissions, in the very near future, will have a big long-term impact on the Greenland ice sheet, and by extension, if it melts, to sea level and human society.”
Greenland's ice sheet currently stands more than 3,050 meters (10,000 feet) above sea level at its thickest point. This is so far into the atmosphere it's able to orchestrate and shift weather patterns, much like a mountain. The current weather patterns are in a fairly good balance – with enough snowfall to make up for the amount of naturally melting ice each year. However, faced with these potential changes, the balance will become disrupted and not enough snow will fall.
Using high-performance supercomputers, the research team plugged in data sets that played out three different emissions scenarios of ice retreat across Greenland, accounting for the many fiddly complexities of flow patterns. They ran their models over 1,500 times, each time accounting for subtle changes in land, ice, ocean, and atmospheric variables.
“Once we had access to satellite observations, we were able to capture the surface velocity of the whole Greenland ice sheet and see how that ice flows. We recognized that some outlet glaciers flow very fast – orders of magnitude faster than the interior of the ice sheet,” added Aschwanden.