Speed of ice melt picks up
Here’s some unsettling news from the other global crisis. Greenland and Antarctica have lost 6.4 trillion tonnes of ice in the past three decades – and unabated, this rate of melting could cause flooding that will affect hundreds of millions of people by the end of the century, Nasa says.
Satellite observations have shown that the regions are losing ice six times faster than they were in the 1990s, according to a new study published in the peerreviewed British journal Nature.
If the current melting trend continues, the regions will be on track to match the worst-case scenario of the Intergovernmental Panel on Climate Change of an extra 17 centimetres of sea level rise by 2100.
‘‘That’s not a good news story,’’ said study lead author Andrew Shepherd, from the University of Leeds in England.
Scientists said the two ice sheets together lost 81 billion tonnes per year in the 1990s, compared with 475 billion tonnes per year in the 2010s – a whopping sixfold increase.
‘‘Today, the ice sheets contribute about a third of all sea level rise, whereas in the 1990s, their contribution was actually pretty small at about 5 per cent,’’ Shepherd told the BBC.
‘‘This has important implications for the future, for coastal flooding and erosion.’’
The resulting meltwater boosted global sea levels by 1.78cm. Of this total sea level rise, 60 per cent resulted from Greenland’s ice loss and 40 per cent from Antarctica’s.
The findings were published by an international team of 89 polar scientists from 50 organisations, and were the most comprehensive assessment to date of the changing ice sheets, Nasa said. – USA Today