Rainfall is probably the most common natural weather event on this planet. But it is not that common when it comes to the ice sheets of Greenland, where temperatures seldom cross the freezing point. But on August 14, 2021 something unprecedented happened. The Summit of Greenland, which is the highest point of its ice sheets, received rain for the first time in recorded history. And scientists have linked this rain event to climate change.
Greenland is the world’s largest island located between the Arctic and Atlantic oceans with three-fourth of its surface permanently covered by ice. The Summit of Greenland is located at an elevation of 3,216 meters. The temperature in the region went above *freezing point for the third time since 2012. This time, it resulted in rain instead of snow extending up to the southeast coast.
“Temperatures have risen above freezing at the peak of the sheet only nine times in the past 2,000 years” according to Martin Stendel, a researcher at the Danish Meteorological Institute. The ice that melts is also warmer and darker now, absorbing more sunlight rather than reflecting it, a phenomenon known as albedo. This happens because newer, light-colored snow melts it and exposes darker snow on the surface of the ice sheet.
Scientists fear that this is a concrete sign of Greenland warming more rapidly than expected. The rainfall this year saw ice melting 7 times more than what is normal at this time of the year in Greenland. A record-breaking summer temperature of more than 20 degrees has also accelerated the melting.
During the summit, the ice sheet received 7 billion tonnes of rain. This rain combined with warm conditions caused a ‘melting event’ that has raised alarms about a rise in global sea levels. The last ‘melting event’ happened on July 28th when 8.5 billion tonnes of mass was lost because of an atmospheric event above the ice sheet. This was enough to cover the US state of Florida in 5 cms of water.
The first event happened in 2019 when 532 billion tonnes of ice was lost to the sea because of unusually hot spring months. This had led to global sea levels rising permanently by 1.5mm. The IPCC report that was released this year also assured that the burning of fossil fuels has accelerated Greenland’s melting in the last two decades. Even though the retreat began several decades ago, the pace of retreat sped up in the 1990s.
The Greenland ice sheet has a surface area 3 times that of France and the Arctic Ocean is expected to witness ice-free summers by 2050 according to some climate models. If this actually happens, densely populated, low-lying cities like New York, Amsterdam and Mumbai would be under threat. Polar bears, who now have to travel hundreds of kilometers looking for food, are also facing the risk of extinction because of melting ice sheets.
The Greenland rainfall is the latest warning sign among the stream of floods, fires and cyclones across the world to remind us of the alarming need to reduce greenhouse gas emissions.
*US National Snow and Ice Data Centre