New Delhi (NVI): Greenland’s ice sheet, largest island in the world, have melted to a point of no return, and will continue to lose ice even if global temperatures stop rising, according to a new study.
The study, published by Ohio State University, shows the satellite data from the last 40 years from more than 200 large glaciers that are draining into the ocean across Greenland, where the snowfall that replenishes the ice sheet each year cannot keep up with the ice that is flowing into the ocean from glaciers.
“The ice sheet is now in this new dynamic state, where even if we went back to a climate that was more like what we had 20 or 30 years ago, we would still be pretty quickly losing mass,” Ian Howat, co-author of the study at Ohio State University, said in a statement.
According to the study, Greenland’s ice sheet dumps more than 280 billion metric tons of melting ice into the ocean each year, making it the greatest single contributor to global sea level rise.
This ice loss has been so massive in recent years, that it has caused a measurable change in the gravitational field over Greenland, it added.
The researchers administrated that, ice melting in Greenland contributes more than a millimeter rise to sea level every year, and that’s likely to get worse. Sea levels are projected to rise by more than 3 feet by the end of the century, wiping away beaches and coastal properties.
However, the complete melting of the Greenland ice sheet could raise sea levels 23 feet (7 inches) by the year 3000.
Moreover, the Coastal states like Florida, and low-lying island nations are particularly vulnerable. Just 3 feet of sea level rise could put large areas of coastline underwater and 40 per cent of the US population resides in coastal areas that are vulnerable to sea level rise.
In 2019, Greenland dumped an unprecedented amount of ice and water into the ocean during the summer when a heat wave from Europe washed over the island.
The ice sheet lost 55 billion tons of water over five days – enough to cover the state of Florida in almost five inches of water.
The study also found that the ice sheet is retreating in rapid bursts, leading to a sudden and unpredictable rise in sea levels, making it difficult to prepare for the effects.
Entire coasts of ice are retreating at once due to climate change, Howat said, adding that all 200 glaciers that make up the Greenland ice sheet have been observed retreating within the same episode.
Although the retreat of the Greenland Ice sheet likely cannot be reversed, it’s just the first in a series of tipping points. If climate change continues at this rate, the rate of melting will get much worse, the study said.
Apart from this, the rising global temperatures and certain human activities can bring about tipping points in other parts of the world, too.
In the Arctic, ice melt is exposing permafrost – frozen soil that releases powerful greenhouse gases when it thaws. If warming thaws enough permafrost, the gases released will trap heat faster than humans’ fossil-fuel emissions.
The future of Greenland ice sheet holds more tipping points – degrees of collapse that will accelerate the glaciers’ melt even more. So, limiting global warming could delay those tipping points and give the world more time to prepare.
Howat also stated, “We’ve passed the point of no return but there’s obviously more to come.”
“Rather than being a single tipping point in which we’ve gone from a happy ice sheet to a rapidly collapsing ice sheet, it’s more of a staircase where we’ve fallen off the first step but there’s many more steps to go down into the pit,” he added.
-RJV
