Burning all fossil fuels would melt all of Antarctica – study
The Antarctic Ice Sheet, the largest ice cap on Earth, stores the equivalent of 58 meters (close to 200 feet) of water in terms of global sea level rise. Should it all melt, cities such as New York, Tokyo and Shanghai would all be submerged.
“Burning the currently attainable fossil fuel resources is sufficient to eliminate the ice sheet,” the study, published in Science Advances on Friday, said.
The good news is that such an event would not happen overnight. It would likely take as much as tens of thousands of years before Antarctica became ice-free.
“This kind of sea-level rise would be unprecedented in the history of civilization,” Ricarda Winkelmann at the Potsdam Institute for Climate Impact Research in Germany, who led the research, told the Wall Street Journal.
The prediction is based on simulating all possible scenarios, such as warming air and ocean temperatures, as well as changes in ice flow and potential snowfall, in a detailed computer Parallel Ice Sheet Model (PISM).
“We examine the ice-sheet evolution over the next ten thousand years with the Parallel Ice Sheet Model (PISM), taking all of these processes into account,” the study reads.
Last year, a separate study showed that massive regions of the ice sheet that makes up West Antarctica has begun to collapse due to warm waters swelling up from the depths and warming the ice sheet from below. Melting this part of the ice sheet would raise sea levels by about four meters over the course of a few centuries.
“If we don’t stop dumping our waste carbon dioxide into the sky, land that is now home to more than a billion people will one day be under water,” Ken Caldeira, a co-author at the US Carnegie Institution, said in a statement.
If continued for 60-80 years, current rates of emissions from oil, coal, and natural gas could make the West Antarctic ice sheet unstable, scientists said. However, that would account for just 6-8 percent of fossil fuel reserves.
In recent years, global leaders have agreed to try to limit global warming to less than 2 degrees Celsius, mainly by reducing carbon output and investing in renewable energy sources.
“If the 2C target … were attained, the millennial sea-level rise from Antarctica could likely be restricted to 2 metres,” scientists wrote in the latest study.
But in the worst-case scenario – in which all fossil fuels are burned and temperatures rise by over 10 degrees Celsius – sea levels would rise by 30 centimeters a decade.
“Human beings haven’t experienced anything like that before,” said Winkelmann, according to the Guardian.
At that pace, sea levels would rise over 30 meters by the end of this millennia and reach over 40 meters in the next, not too far from what the whole of Antarctica has stored now.
“Thus, if emissions of fossil-fuel carbon result in warming substantially beyond the 2C target, millennial-scale rates of sea-level rise are likely to be dominated by ice loss from Antarctica. With unrestrained future CO2 emissions, the amount of sea-level rise from Antarctica could exceed tens of meters over the next 1000 years and could ultimately lead to the loss of the entire ice sheet,” the researchers concluded.
While these findings are just the result of a computer simulation, the consequences the scientists looked into are possible.
“The west Antarctic ice sheet may already have tipped into a state of unstoppable ice loss, whether as a result of human activity or not,” said Anders Levermann, another member of the research team at the Potsdam Institute, the Guardian reported. “But if we want to pass on cities like Tokyo, Hong Kong, Shanghai, Calcutta, Hamburg or New York as our future heritage, we need to avoid a tipping in east Antarctica.”