Extract from ABC News
Global warming has increased the speed at which glaciers in Greenland are melting fivefold over the last 20 years, according to scientists from the University of Copenhagen.
Key points:
- Glaciers in Greenland are decreasing by 25 metres annually
- Researchers at the University of Copenhagen labelled the results "quite disturbing"
- But they say glaciers respond to climate change quickly, meaning it is not too late to prevent worse changes
Greenland's ice melt is of particular concern, as the ancient ice sheet holds enough water to raise sea levels by at least 6 metres if it were to melt away entirely.
A study of a thousand glaciers in the area showed the rate of melting has entered a new phase over the last two decades, Anders Anker Bjørk, assistant professor at the Department of Geosciences and Natural Resource Management at the University of Copenhagen, told Reuters.
"There is a very clear correlation between the temperature we experience on the planet and the changes we observe in how rapidly the glaciers are melting," Dr Bjørk said.
The glaciers on average decrease by 25 metres annually, compared with 5-6 metres two decades ago.
Scientists reached their conclusion after studying the development of the glaciers over 130 years through satellite imagery and 200,000 old photos.
The University of Copenhagen said the study was the most comprehensive monitoring of Greenland's glaciers to date.
Only one of the country's 22,000 glaciers has been monitored continuously since the mid-1990s. Others seemed unaffected by rising temperatures just a few years ago.
"Previously, we saw areas in northern Greenland, for example, that were lagging behind and melting less compared to the hardest hit glaciers," Dr Bjørk said.
"This generated a bit of doubt about how serious things were in these areas.
"At the same time, no one before us had ever shed light on such a long period of time, which precipitated doubts as well.
"But now, the picture is conclusive: The melting of all glaciers is in full swing, there is no longer any doubt."
The Greenland ice sheet contributed 17.3 per cent of the observed rise in sea level between 2006 and 2018 and glaciers have contributed 21 per cent.
Ice sheet expected to melt further as temperatures rise
The world has already warmed by nearly 1.2 degrees above pre-industrial temperatures.
This year was "virtually certain" to be the warmest in 125,000 years, scientists from the European Union said earlier this month.
Lowering temperatures would require a global effort to minimise greenhouse gases in the atmosphere, said Jørgen Eivind Olesen, Institute Director of the Climate Institute at Aarhus University.
"I believe we can prepare for those glaciers to continue to melt at increasing speeds," he said.
Glaciers in Greenland have often been used to anticipate the effects of climate change on Greenland's ice sheet.
"If we start to see glaciers losing mass several times faster than in the last century, it can make us expect that the ice sheet will follow the same path, just on a slower and longer time scale," William Colgan, senior researcher at the Geological Survey of Denmark and Greenland, said.
Dr Bjørk said the research was "quite disturbing".
"Because we're well aware of where this is headed in the future," he said. "Temperatures will continue to rise and glaciers will melt faster than they do now.
"But our study also shows that glaciers respond to climate change very quickly, which is in itself positive because it tells us that it's not too late to minimise warming.
"Everything that we can do to reduce CO2 emissions now will result in slower sea level rise in the future."
ABC/Reuters
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