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After a very brief respite in 2017 and 2018, the Greenland Ice Sheet lost a record amount of ice in 2019, shedding a mind-blowing 532 billion metric tons in just one year.
That's the equivalent of six Olympic-sized swimming pools of melting ice every single second (although, most of the melting occurred during the warmer summer months).
Scientists in Germany have used satellite imagery and modeling data to conclude that last year saw a new record loss of mass in the Greenland Ice Sheet: a total loss of 532 billion tons, smashing the previous record of 464 billion tons lost in 2012. Altogether, the quantity of ice melting in Greenland during 2019 caused the global sea levels to rise by 1.5 millimeters (0.06 inches). Along with melting, the research also showed that 2019 had a lower than long-term average snowfall, further adding to the overall loss of mass.
The bleak new findings were published in the Nature journal Communications and Environment this week, and back up similar findings published this year.
The researchers analyzed data from NASA satellite missions GRACE (Gravity Recovery and Climate Experiment) and GRACE-FO satellite missions from 2003 to 2019, which detected anomalously low melt in 2017 and 2018, followed by record-high melt in 2019.
“After a two-year 'breather', in 2019 the mass loss increased steeply and exceeded all annual losses since 1948, and probably for more than 100 years," Ingo Sasgen, first study author and a glaciologist at the Helmholtz Centre for Polar and Marine Research in Germany, said in a statement.
“2017 and 2018 were very cold years in Greenland, with high snowfall. We see substantial variations from year to year. But the five years with the highest losses since 1948 were all in the last decade.”
The Arctic is suffering some of the harshest and most immediate effects of climate change through a process known as polar amplification. For example, this recent observation wasn’t just driven by rising temperatures in the area. The study also notes that the melting was also amplified by reductions in the Arctic's surface albedo (its ability to reflect the Sun's rays). In other words, previous melting has gradually removed large swathes of shiny reflective ice and left behind darker rock, which absorbs more heat and further warms the local area.
"It is devastating that 2019 was another record year of ice loss," commented Dr Twila Moon, a research scientist at the University of Colorado at Boulder, who was not involved in the study. "In 2012, it had been about 150 years since the ice sheet had experienced similar melt extent, and then a further 600+ years back to find another similar event. We have now had record-breaking ice loss twice in less than 10 years, and the ice sheet has lost ice every year for the past 20.
"If everyone’s alarm bells were not already ringing, they must be now. "
Greenland’s ice loss is no secret. Last week, scientists reported that the Greenland Ice Sheet had reached “a point of no return,” which means the ice sheet will continue shrinking even if climate change was hypothetically stopped today. Typically, the ice sheet is able to recover each summer's spell of melting through a fresh replenishing fall of snow in the winter months. However, as this new record melt further highlights, it's now becoming impossible for the Greenland Ice Sheet to recover the losses it encounters through ice melt each summer.
