The three largest glaciers in Greenland — which hold enough frozen water to lift global sea levels some 1.3 metres — could melt faster than even the worst-case warming predictions, research published Tuesday showed.
Until 2000, the main driver of sea level rise was melting glaciers and the expansion of ocean water as it warms. But over the last two decades, the world’s ice sheets atop Greenland and Antarctica have become the single largest source of sea level rise.
A team of researchers based in Denmark and Britain used historical images and a host of other data to estimate how much ice had been lost from Greenland’s Jakobshavn Isbrae, Kangerlussuaq Glacier and Helheim Glaciers in the 20th century.
They found that Jakobshavn Isbrae lost more than 1.5 trillion tonnes of ice between 1880-2012, while Kangerlussuaq and Helheim lost 1.4 trillion and 31 billion tonnes from 1900–2012, respectively.
The ice melt has already contributed more than eight millimetres to global sea levels, the researchers wrote.