According to a comprehensive new study, the world’s glaciers are melting at an accelerating rate.
The French-led team assessed the behavior of almost all documented ice flows on the planet.
Researchers have found that they lost almost 270 billion tons of ice a year during the first two decades of the early 21st century.
Meltwater currently produced accounts for about one-fifth of global sea level rise.
The numbers involved are quite difficult to imagine, so team member Robert McNab, from the University of Ulster և Oslo, uses similarities.
“Over the last 20 years, we have seen glaciers lose about 267 gigatonnes (Gt) a year. So if we take that amount of water and divide it across the island of Ireland, that’s enough to cover it all. “Ireland is 3 meters into the water every year,” he told the BBC World Service this week.
“And the total loss is accelerating. It is growing at about 48 Gt / year over the decade. ”
The global glacier inventory contains 217,175 glaciers.
Some are smaller than a football field; others can compete in a medium-sized country like the United Kingdom. What almost everyone has in common is that they are thinning, receding in changing climates, either through warmer winds or stronger melting, or the patterns of snowfall feeding on glaciers have changed.
A team led by Romain Hugonet from the University of Toulouse in France used images from NASA’s Terra satellite, which was launched in 1999, as the main source of data.
Enormous computing power was put into the process of interpreting these images to bring out changes in the height, volume, and mass of glaciers by 2019.
The team believes that its approach has reduced the uncertainty of its results by less than 5% overall. And each of the approximately 200,000 glaciers they studied in the study is based on the same methodology.
“This new study is a major breakthrough as we get a high spatial solution, at the same time it provides time change over two decades based directly on satellite data, which is new,” explained Matthias Huss, co-author of the Swiss Federal Institute of Technology. :
“This data set has been validated by a huge number of additional, independent measurements. It is very accurate to drastically reduce the uncertainties of previous studies.”
A group led by the University of Leeds published their own assessment of glacier ice loss in The Cryosphere magazine in January.
It reached very similar numbers. It reported an average annual loss of 289 Gt / year, an acceleration of 52 Gt / year / decade. 8% difference.
Leeds professor Andy Sheffard told BBC News: “Glacier melting accounts for a quarter of the Earth’s ice loss during the satellite period.”
“Although the rate of melting of the glacier has been steadily increasing, the rate has slowed due to the rapid loss of ice from Antarctica և Greenland և they remain our primary priority for future sea level rise.”