Feeds

Greenland melt threshold lower than thought

Ice could disappear with half as much warming: study

Protecting against web application threats using SSL

Spanish and German scientists have have alarmed the international environmental community with modeling suggesting that Greenland’s ice sheets could disappear at lower temperatures than previously thought.

The study was conducted by Spain’s Universidad Complutense de Madrid and the Potsdam Institute for Climate Impact Research in Germany. They found that rather than a best-estimate temperature rise (compared to pre-industrial levels) of 3.1°C, Greenland’s ice would eventually succumb to a rise of as little as 1.6°C.

The good news is that complete loss of the ice sheet is, even under the Spanish-German model, about 2,000 years distant. However, they say, this is considerably faster than has happened before on Earth, and is more than an order of magnitude quicker than would happen if warming were contained.

If temperatures are contained to within 2°C of pre-industrial levels, the ice sheet would last another 50,000 years, the authors say.

According to Reuters, the research, published in the journal Nature Science Change, suggests scientists have been too optimistic in estimating the temperature needed to trigger substantial ice loss in Greenland.

“Our study shows that a temperature threshold for melting the (ice sheet) exists and that this threshold has been overestimated until now,” the paper states (abstract here).

The temperature in question is that at which the mass balance of Greenland’s surface ice “turns negative” – in other words, its summer melt is faster than its winter replenishment.

Using a “fully coupled model” the researchers suggest that while “one intermediate equilibrium state is possible … for sufficiently high initial temperature anomalies, total loss of the ice sheet becomes irreversible”.

In other words, while commendably avoiding the emotive term “tipping point”, the researchers do suggest that such a state exists. It’s feasible, in their study, that a point exists where even a reduction in temperatures wouldn’t reverse the loss of the ice sheet.

Both the previous estimates and the new estimate have considerable error bars: the former model for Greenland ice loss fell between 1.9 and 5.1°C, while the new model puts the maximum range between 0.8 and 3.2°C.

“The timescale of melt depends strongly on the magnitude and duration above this critical threshold,” the abstract says. ®

Reducing the cost and complexity of web vulnerability management

More from The Register

next story
PORTAL TO ELSEWHERE scried in small galaxy far, far away
Supermassive black hole dominates titchy star formation
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Edge Research Lab to tackle chilly LOHAN's final test flight
Our US allies to probe potential Vulture 2 servo freeze
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
Cracked it - Vulture 2 power podule fires servos for 4 HOURS
Pixhawk avionics juice issue sorted, onwards to Spaceport America
Archaeologists and robots on hunt for more Antikythera pieces
How much of the world's oldest computer can they find?
Who wants to be there as history is made at the launch of our LOHAN space project?
Two places available in the chase plane above the desert
prev story

Whitepapers

Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
The next step in data security
With recent increased privacy concerns and computers becoming more powerful, the chance of hackers being able to crack smaller-sized RSA keys increases.