(ORDO NEWS) — The Greenland ice sheet, second in size only to the frost cap of Antarctica, is several million cubic kilometers of fresh water held by a combination of rock and sub-zero temperatures.
Until the end of the 20th century, the likelihood that the amount of ice that had gone to the sea would be replaced by the dust of precipitation was high. Today, there is a 99 percent chance that more water will go into the Atlantic than land on land.
What determines Greenland’s annual ice budget depends on numerous geological and meteorological features, many of which scientists have yet to determine. Now, an international team of researchers has refined their estimates of the factors that are holding back the island’s huge reservoir of frozen water.
Based on the analysis of ice fluctuations between 2000 and 2019, it can be assumed that even if the climate stabilizes, we will lose just over 3 percent of the existing ice.
To put this into perspective, we are talking about enough water being dumped into the oceans to raise the water level by 27.4 centimeters, or nearly a foot. This is if the future climate will again and again repeat the last decades of temperatures and precipitation.
If the worst year in two decades were to be indicative of Greenland’s water cycle, sea levels would rise by about 78.2 centimeters (over 2.5 feet) as a result of ice loss.
To be optimistic, in more favorable years, there may even be a return to ice growth.
Based on the history of ice loss and accumulation in Greenland, these predictions can be seen as long-term, based on cycles that occur over thousands of years.
Unfortunately, we live in unprecedented times. While the new model doesn’t tell us exactly on what time scale this operation could occur, the researchers suggest that given what we know about our world today, we can look forward to one or two centuries.
As for tomorrow? Of course, what our world will look like in the coming years depends largely on how we act now.
But barring a spontaneous ice age, Greenland will be in debt to slowly melting ice for the foreseeable future.
The key to a new method of understanding the equilibrium of ice accumulation and melting – what is known as surface mass balance – is to focus on changes in ice geometry under given climatic conditions.
The speed at which glaciers flow into the sea is limited by the amount of ice pressing on a certain area. Considering how Greenland’s glaciers are collapsing around its coastline, one can calculate the mandatory loss of ice that is already being pushed into the Atlantic under its own pressure.
At some point, the steady sliding of glacial ice and meltwater may once again balance the weight of snow accumulating on Greenland’s peaks and plateaus.
The exact definition of this moment will depend on whether we have more years like 2018 – with relatively little ice loss – or years as terrible as 2012, when there were days when 97 percent of the ice sheet showed signs of surface melt.
In this worst-case scenario, much more of the Greenland ice will end up in drinking water, with glaciers retreating at a rate that precipitation simply cannot match.
If that happens, we will need to worry about more than sea level rise. This volume of fresh water dumped into the North Atlantic would float on top of the denser salt water, effectively dampening the main ocean current that is helping to cool the planet’s equator.
Every fraction of a degree rise in temperature brings us closer to this grim possibility. In the so-called “business as usual” scenario where regulations fail to mitigate rising emissions, we can expect Greenland to be much less frozen by 2200.
We can avoid this fate. Although some of the Greenland ice is doomed to extinction, it is in our power to preserve its glaciers for a long time.
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