New data from NASA’s Grace satellites show Greenland’s ice sheet shrinking by 532 billion tonnes last year, with researchers dubbing it ‘shocking’ and perhaps the biggest loss for centuries, if not millennia.
For context, the amount of glaciers that fell into the ocean would have filled seven Olympic-sized swimming pools per second. From data collected since 2003, the annual loss was an average of 255 billion tonnes – the amount lost in July last year alone.
Greenland’s ice loss has been increasing in recent decades, with scientists previously noting high rates of melting in 2019. However, new data has accounted for snowfall and allowed for the net loss to be calculated – fresh statistics in the fight to raise awareness of climate change, a huge factor in melting ice caps and therefore rising sea levels.
Researchers from the Alfred Wegener Institute in Bremerhaven, Germany, attributed Greenland’s catastrophic loss to ‘blocking patterns’ in weather, contributing to warmer temperatures. Also, when snow on top of the ice melts, the darker ice below absorbs more of the sun’s heat.
In 2019 alone, around 96% of the ice sheet experienced melting, a massive difference compared to the average of 64% between 1981 and 2010.
[2019 was] really shocking and depressing in terms of the numbers. But it’s also not very surprising, because we had other strong melt years in 2010 and 2012, and I expect we will see more and more. The real message is that the ice sheet is strongly out of balance.
Sasgen added: ‘If we look at the record melt years, the top five occurred in the last 10 years, and that is a concern. But we know what to do about it: reduce CO2 emissions.’
If the country’s entire ice sheet melted, sea level would rise by six metres. However, we’re not at that point yet, and if we manage to curb carbon emissions, the melting will slow down.
If we reduce CO2, we will reduce Arctic warming and we will therefore also reduce the sea level rise contribution from the Greenland ice sheet. So even though it might eventually disappear in large part, it happens much slower, which would be better as it would allow more time for the 600 million people living near coasts to move away.
Yara Mohajerani, of the University of California Irvine in the US, urged that ‘these results come at a crucial time… it is crucial to closely monitor the changes in [ice] mass of the sheet, and Sasgen and his colleagues have taken an important step in that direction’.
Since meltwater is freshwater, it dilutes the salt content of the surrounding ocean, which contributes to slowing the Gulf stream system.
If we wanted to make the 500bn tonnes of freshwater added in 2019 as salty as ocean water, about 200,000 Panamax-class cargo ships full of salt would need to dump their load into the Atlantic.
The research was published in the journal Communications Earth & Environment. Sasgen added that ‘we have entered a completely different state… Greenland has become bipolar in a way’.
Originally published at unilad