Feeds

Greenland melt threshold lower than thought

Ice could disappear with half as much warming: study

3 Big data security analytics techniques

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. ®

Top three mobile application threats

More from The Register

next story
So, just how do you say 'the mutt's nuts' in French?
Vital linguistic question interrupts LOHAN spaceplane mission
95 floors in 43 SECONDS: Hitachi's new ultra-high-speed lift
Guangzhou skyscraper denizens to hold on to hats
Most Americans doubt Big Bang, not too sure about evolution, climate change – survey
Science no match for religion, politics, business interests
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
LOHAN and the amazing technicolor spaceplane
Our Vulture 2 livery is wrapped, and it's les noix du mutt
Liftoff! SpaceX Falcon 9 lifts Dragon on third resupply mission to ISS
SpaceX snaps smartly into one-second launch window
STEALTHY NANOROBOTS dress up as viruses, prepare to sneak into YOUR BODY
Cloaking techniques nicked from viruses tackle roadblocks on way to medical frontier
prev story

Whitepapers

Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.