Watery Greenland


Another piece of global warming underestimated, the Guardian reports.

Melting ice from the coast of Greenland could make a much bigger contribution to rising sea levels than has previously been thought, a new study suggests.

Scientists believe a previously overlooked side-effect of global warming could greatly increase the rate of melting of the vast Greenland ice sheet.

That sounds bad.

The ice covers 1.7m sq km (656,000 sq m), an area three times the size of Texas. If all the ice melted and flowed into the sea, oceans around the world would rise by as much as six metres (20ft), causing extensive damage to coastal communities.

While such a disaster is not expected to happen, ice losses from Greenland are predicted to contribute 22 cm (8in) to global sea levels by 2100.

But the new findings related to lakes formed from melted ice and snow indicate that this figure may be significantly too low.

The study shows that as Arctic temperatures rise, Greenland will develop a rash of these “supraglacial” lakes which are expected to spread much further inland.

And what will that do?

One key effect the lakes have, once they reach a critical size, is to drain through fractures in the ice to reach the ice sheet base. Like a lubricant, the lake water causes the melting ice to slide more rapidly into the ocean.

The lakes also have a direct impact on ice sheet melting because, being darker than ice, they absorb more of the sun’s heat.

Lead researcher Dr Amber Leeson, from the University of Leeds’ School of Earth and Environment, said: “Supraglacial lakes can increase the speed at which the ice sheet melts and flows, and our research shows that by 2060 the area of Greenland covered by them will double.”

It will make everything a lot worse, that’s what it will do.

Comments

  1. quixote says

    “Positive feedback loops are often bad like this.”

    Can’t be said often enough. So, there’s at least a meter rise in sea level guaranteed by the end of the century due to the Antarctic ice sheet which is on a now-unstoppable slide seaward. Say another meter from Greenland and other glacial melt. Another 15-20 centimeters of inescapable thermal expansion. That’s about 7-8 feet rise just based on current factors, without further positive feedback.

    Meanwhile, I just checked Zillow and a nice upper middle class house in Coral Gables, Florida, elevation 3 ft, is going for $2,149,000.

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