Scientists found that Greenland is melting faster than they previously thought. And it’s not the isolated glaciers that are melting; it is the inland ice from the ice sheet itself!
In a new study published in the Proceedings of the National Academy of Sciences, it was revealed that the largest portion of ice loss sustained from early 2003 to mid-2013 came from Greenland’s southwest region. This particular area is mostly devoid of large glaciers, so where is ice discharge coming from?
“Whatever this was, it couldn’t be explained by glaciers, because there aren’t many there,” Michael Bevis, lead author of the paper and professor at The Ohio State University said. “It had to be the surface mass — the ice was melting inland from the coastline.”
Since 2002, scientists have been monitoring the Greenland ice sheet through NASA and Germany joint project GRACE. According to their measurements, Greenland lost approximately 280 gigatons of ice per year between 2002 and 2016. That is equivalent to 0.03 inches rise of sea level each year.
However, there is a twist. Since 2012, the Greenland ice has been melting four times faster than in 2003. And this acceleration was concentrated in the southwest Greenland.
Cause of Melting
A deadly combination of global warming a the negative phase of a natural weather phenomenon called the North Atlantic Oscillation is said to be the culprit behind the rapidly melting ice. The North Atlantic Oscillation, at its negative phase brings warmer air and sunny weather to West Greenland. However, Bevis said that before 2000, this oscillation did not make such an effect.
“These oscillations have been happening forever. So why only now are they causing this massive melt? It’s because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained, global warming,” Bevis explained.
Bevis compared the situation to coral bleaching. In oceans, coral bleaching happens when the water hits a certain ‘temperature.’ And in Greenland’s case, global warming has brought a significant amount of that ‘temperature.’ Combined with the oscillation, this caused large areas of Greenland to melt.
And once it begins, there is no turning back.
“The only thing we can do is adapt and mitigate further global warming…This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point,” Bevis said. “Once you hit that tipping point, the only question is: How severe does it get?”
Rise in Sea Levels
The Greenland ice sheet is the second largest ice mass in the world, after only the Antarctic ice sheet. It covers an area of 1,710,000 square kilometres (660,000 square miles) and has thickness of 2,000-3,000 meters (6,600-9,800). If the entire ice sheet were to melt, it will cause a global sea level rise of 7.2 meters or 24 ft. Of course, that is in centuries.
However, if global warming continues to turn severe, there’s no guarantee that the melting won’t turn even faster. Experts warn that at worse, the global warming threshold could be crossed in a few decades.
With this, the Southwest Greenland, which has not been previously considered as a serious threat, will become a major contributor in the rise of sea level in the future. What’s more, the melting of the Antarctica ice is rapidly rising too. This will cause serious implications to US coastal cities which includes New York and Miami, as well as island which are vulnerable to rising sea levels.