Recent Climate Change Altering Greenland's Ice Sheet

Greenland's projected sea level rise due to meltwater runoff is likely to be higher than previously predicted by researchers.

Although, Greenland's ice sheet has traditionally been pictured as a bit of a sponge for glacier meltwater, but new research has found that climate change is changing its structure, thereby reducing its ability to buffer its contribution to increasing sea levels.

For the study, the researchers analysed data from three expeditions to the Greenland ice sheet in 2012, 2013 and 2015. The project involved drilling firn cores in the interior of the Greenland ice sheet. Firn is multi-year compacted snow that is not as dense as glacier ice. Instead, it forms a porous near-surface layer over the ice sheet.

30 Lakh Indians Join Millions Worldwide Against Climate Change
Over 400,000 Indians sent postcards and another 16 lakh took part in a global campaign to demand urgent action to tackle poverty, inequality and climate change.

‘An extreme melt that occurred in 2012 on Greenland's ice sheet caused a layer of solid ice, several metres thick, to form on top of the porous firn in the low elevation areas of the ice sheet.’

"The study looked at very recent climate change on the ice sheet, how the last couple of years of melt have really altered the structure of the ice sheet firn and made it behave differently to future melt," said study co-author William Colgan, professor at York University in Toronto, Canada.

The team set up several camps and drilled a series of shallow firn cores about 20 metres deep during their time on the ice sheet. They were surprised by what they found. An extreme melt that occurred in 2012 caused a layer of solid ice, several metres thick, to form on top of the porous firn in the low elevation areas of the ice sheet.

"In subsequent years, meltwater could not penetrate vertically through the solid ice layer, and instead drained along the ice sheet surface toward the ocean," Colgan said.

With the Big Animals Gone Forever, Climate Change Could Get Worse
A decline in fruit-eating animals such as large primates, tapirs and toucans could have a knock-on effect for tree species.

"It overturned the idea that firn can behave as a nearly bottomless sponge to absorb meltwater. Instead, we found that the meltwater storage capacity of the firn could be capped off relatively quickly," Colgan noted.

Because the models scientists use to project Greenland's sea level rise contribution do not presently take firn cap-off into consideration, it means that Greenland's projected sea level rise due to meltwater runoff is likely higher than previously predicted. The study was published in the journal Nature Climate Change.

Climate Change May Positively Impact Rice, Tea in Northeast
Scientists looked at climate data, such as temperature, humidity and precipitation and found that it is going to positively impact rice and tea in northeast.

Source-IANS

Climate Change Warming Lakes Around the World at Alarming Rate
Lakes are warming at an average of 0.34 degrees Celsius each decade all around the world, threatening freshwater supplies and ecosystems.