Greenland ice sheet melting at accelerated rate threatening sea level rise
The Greenland ice sheet is losing its mass at an accelerating rate, scientists have said, making it the single biggest contributor to rising sea levels.
The study, published in the journal Communications Earth & Environment, found that the rate of future ice loss was uncertain but that current ice loss is now 14 per cent greater than the rate observed during 1985-1999.
In addition, they said the chance that the ice sheet would gain mass again under current typical climate conditions is around 1 per cent.
The rate of ice loss had slowed for a two-year period amid cooler summers and higher snowfall in western Greenland through 2018.
But last year, as warm air flowed northward from lower latitudes, the frozen island experienced a record loss in its ice mass, geoscientist Ingo Sasgen of the Alfred Wegener Institute in Germany said.
In April, scientists found that hundreds of billions of tons of ice melted over the course of the year, but the loss wasn’t caused by warm temperatures alone. “Exceptional” atmospheric circulation patterns that are not included in current climate models were discovered that contributed in a major way to the ice sheet’s rapid loss of mass. It is thought this could mean future melting rates could be underestimated by about half.
Speaking to Reuters, Sasgen said: “We are likely on the path of accelerated sea level rise. More melting of the ice sheet is not compensated by periods when we have extreme snowfall.”
The new study used data collected by satellites to the gravitational force of the ice mass, which scientists can use to calculate how much snow and ice is locked within.
Other research has shown the melting is being helped by water pooling atop the ice and at meltwater streaming between the ice sheet and the bedrock beneath.
“It’s always depressing to see a new record,” Sasgen said. “It is hard to tell if these [weather] patterns will be the new normal, and which pattern will occur with which frequency.”
If 2019’s rate of ice loss were to continue, it is estimated that the annual impact on sea levels could cause increasing coastal flooding that affects up to 30 million more people each year by the end of the century.
This week, the UK set legally binding targets for air quality, waste reduction, biodiversity and cleaner water as part of a package of measures designed to protect the environment and tackle climate change.
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