Rain fell at the best level on the Greenland ice sheet final week for the first time on report, one other worrying signal of warming for the ice sheet already melting at an rising fee, scientists mentioned on Friday, August 20.
“That’s not a healthy sign for an ice sheet,” mentioned Indrani Das, a glaciologist with Columbia University’s Lamont-Doherty Earth Observatory. “Water on ice is bad… It makes the ice sheet more prone to surface melt.”
Not solely is water hotter than the standard snow, additionally it is darker – so it absorbs extra daylight.
Unprecedented rise
This meltwater is streaming into the ocean, inflicting sea ranges to rise. Already, melting from Greenland’s ice sheet – the world’s second-largest after Antarctica’s – has precipitated round 25% of world sea stage rise seen over the previous few many years, scientists estimate. That share is predicted to develop, as world temperatures improve.
The rain fell for a number of hours at the ice sheet’s 3,216-metre summit on August 14, the place temperatures remained above freezing for round 9 hours, scientists at the U.S. National Snow and Ice Data Center mentioned. Temperatures at the ice cap nearly by no means carry above freezing, however have now executed so thrice in lower than a decade.
In complete, 7 billion tonnes of rain fell throughout Greenland over three days, from August 14 by August 16 – the most important quantity since information started in 1950. The rain and excessive temperatures triggered in depth melting throughout the island, which suffered a floor ice mass loss on August 15 that was seven occasions above the typical for mid-August.
The record-breaking rain is the newest in a string of warning indicators.
Greenland skilled an enormous melting occasion in late July. ,when sufficient ice melted in a single day to cowl the U.S. State of Florida in 2 inches (5 cm) of water.
That melting occasion and final week’s rain had been each brought on by air circulation patterns which meant heat, moist air briefly coated the island.
“This alarming rain at the summit of Greenland is not an isolated event,” mentioned Twila Moon, deputy lead scientist with the U.S. National Snow and Ice Data Center.
Along with rising floods, fires, and different extremes, it’s one in every of many “alarm bells” signalling the necessity to cut back greenhouse fuel emissions, she mentioned.
“We really have to stay laser-focused on adapting, as wella s reducing the potential for those to become truly devastating.”
