Greenland’s ice sheets ‘on pace’ to melt at fastest rate in 12,000 years

1 Oct 2020

Image: © Vytenis/Stock.adobe.com

Researchers from the University at Buffalo have warned that the world must go on a ‘massive energy diet’ to address the climate emergency.

Greenhouse gas emissions are driving ice in Greenland to melt quicker than in any century in the past 12,000 years, according to new research. In a study published in Nature, scientists at the University at Buffalo College of Arts and Sciences in New York warned that the rate of loss this century could be “greater than anything we’ve seen” since the beginning of the Holocene.

The Holocene is the current geological epoch. It began after the last ice age around 12,000 years ago and is characterised by global change caused by human activity.

To study the melting ice rate, researchers simulated changes in Greenland’s ice sheets from the start of the Holocene until the year 2100. They found that the rate is accelerating and, if emissions continue to rise, the rate of loss could be four times greater than the highest values experienced in the last 12,000 years.

The team at Buffalo said the largest ice mass losses in the early Holocene were around 6,000bn tonnes per century. It estimated that the first two decades of this century alone have matched that figure.

The paper’s lead author and professor of geology at Buffalo, Jason Briner, said: “Basically, we’ve altered our planet so much that the rates of ice-sheet melt this century are on pace to be greater than anything we’ve seen under natural variability of the ice sheet over the past 12,000 years.

“We’ll blow that out of the water if we don’t make severe reductions to greenhouse gas emissions.”

Briner’s team tested the accuracy of its model by comparing results of the simulations to historical evidence. The modeled results, it said, matched well with real measurements of the ice sheets captured by satellites and aerial surveys in recent decades.

One of the biggest impacts of the melting ice sheets is the effect on sea levels. At around five times the size of California, Greenland is the world’s largest island. In the past 20 years, its ice sheet has lost around 280 cubic km every year, causing sea levels to rise by 0.7mm each year.

According to Briner, the world needs to go on a “massive energy diet” to prevent acceleration in the melting rate. If the right steps are taken, he said, his team’s model “predicts that the Greenland ice sheet’s rate of mass loss this century will be only slightly higher than anything experienced in the past 12,000 years”.

Lisa Ardill was careers editor at Silicon Republic until June 2021

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