The news that the western ice sheets of Antarctica now appear to be headed for irreversible melting was bad enough. Additional data coming in suggests matters may be even more serious.
The BBC reports on the latest ice measurements from ESA's Cryosat.
Antarctica is now losing about 160 billion tonnes of ice a year to the ocean - twice as much as when the continent was last surveyed.
The new assessment comes from Europe's Cryosat spacecraft, which has a radar instrument specifically designed to measure the shape of the ice sheet.
The melt loss from the White Continent is sufficient to push up global sea levels by around 0.43mm per year.
Scientists report the data in the journal Geophysical Research Letters.
The new study incorporates three years of measurements from 2010 to 2013, and updates a synthesis of observations made by other satellites over the period 2005 to 2010.
Meanwhile, the Greenland Ice Sheet may be more susceptible to melt than previously thought. Previous understanding of the Greenland ice cap pictured it roughly as a mass of ice sitting on top of a flat land mass.
Scientific American picks up on new findings that such is not the case.
Many older models of Greenland assumed that its massive ice sheet sat on bedrock that was relatively flat, even though scientists did not know the full thickness of the ice. There also was an assumption that many melting glaciers on the ice sheet's periphery eventually would retreat to higher ground on this flat bedrock, cutting off contact with warm ocean waters and slowing down the ice sheet's shedding.
The discovery of the valleys—which stretch more than 100 kilometers (62.1 miles) into Greenland's interior in some cases—suggests instead that some of Greenland's most vulnerable outlet glaciers will just keep retreating and retreating along deep canyons. About 100 of the valleys sit far below sea level and are attached to glaciers on Greenland's periphery that already are shedding ice, like Jakobshavn Isbræ glacier, said Morlighem.
That means that as these glaciers retreat, their fronts will remain in contact with warm ocean water that melts ice, rather than hitting higher ground anytime soon. "As long as the vertical face of the glaciers remains in contact with the ocean, they are vulnerable," said Morlighem*.
*
Mathieu Morlighem, associate project scientist at the University of California, Irvine
Between Antarctica and Greenland, this means models of sea level rise as the ice melts will have to be revised. (Too bad, North Carolina.)
Climate Change - it's not simply a matter of everything just getting hotter from global warming. It's all kinds of systems interacting in ways we are only starting to get a handle on. Scientific American has a slide show of how warming is affecting the world in particular locales, like Russia and Canada.
Those insights come from a study by Zhaohua Wu, an assistant professor of meteorology at Florida State University, published in Nature Climate Change. Wu and a team of fellow meteorologists analyzed worldwide temperature data in unprecedented detail, comparing the readings every decade since 1950 against levels in 1901.
Slideshow here. The captions under the slides explain the changes. It's not just the arctic regions that are heating.
Interesting times ahead. We may yet have the small satisfaction of telling today's Climate Change denialistas "We told you so" while they are still around to hear it.