Social Media Sidebar

Announcement

Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

People say we're running out of energy. That's only true if we stick with these old 19th century technologies. We are awash in energy from sunlight.

 

Ray Kurzweil

 

The underestimated rise in sea levels

RATE THIS! +6
Posted in Science on 1st Dec, 2012 07:33 PM by AlexMuller

There are four major mechanisms: the thermal expansion of oceans in a warming world; the loss of ice from the Greenland and Antarctic ice sheets; the melting of mountain glaciers and ice caps (such as those in the Himalayas); and the extraction and discharge of groundwater.

 

The likely culprits are continental ice sheets. "[In IPCC models], the two big ice sheets in Greenland and Antarctica contribute nothing to future sea level rise, because they assume that the mass loss from Greenland is balanced by ice gain in Antarctica due to higher snowfall rates," says Rahmstorf.

 

But satellite data show that the ice sheets are losing ice to the oceans.

 

If the models have not accurately reproduced what happened in recent years, it is likely that their projections for the future are not correct either. Since 2007, the IPCC has recognised this. Its initial projection of a maximum sea level rise of 60 centimetres by 2100 has been upped to include an additional 20-centimetre rise due to ice sheets melting.

 

And the data are clear: from 1990 to 2000, the melting of Greenland and Antarctic ice sheets added about 0.25 millimetres a year to global sea level rise. For 2005-2010, that number has increased to about 1 millimetre a year

 

Greenland is losing the most ice, causing sea level to rise by about 0.75 millimetres per year. What's happening in Antarctica is more nuanced. East Antarctica is gaining mass because of increased snowfall, but this is more than offset by the loss of ice from West Antarctica, particularly along the Amundsen Coast, where warm water is melting ice shelves from beneath. This is leading to thinning and speed-up of glaciers, such the Pine Island and Thwaites glaciers.

 

Until now, sea level rise from the extraction of groundwater (which eventually ends up in the sea) has been countered by dams built on rivers over the last century, which hold water back on land. But the best sites for dams have now been utilised, so we can't expect to store more water on land.

 

As we extract more groundwater for irrigation – a trend that could increase as climate change causes droughts – it could add up to 10 centimetres to the sea level by 2100, according to Rahmstorf. "This will become a net contribution to sea level rise in the future," he says. "Not big, but not negligible."



Read original article » Back to category

Comments



 

Recent headlines

  • Posted in Medicine on 2017-08-21 19:26:00
    Darmiyan’s software detects early stages of Alzheimer’s..read more
    Posted in Business on 2017-08-21 19:20:53
    Google needs to pay Apple a fortune to remain the default.....read more
    Posted in Medicine on 2017-08-21 19:15:22
    Artificial Intelligence beats doctors at diagnosing.....read more
    Posted in Science on 2017-08-20 16:55:58
    Computer Approaches Human Skill for First Time in Mapping.....read more
    Posted in Science on 2017-08-20 16:51:23
    Researchers use polystyrene to make next-generation of.....read more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in about.....read more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for commercial.....read more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 Downloads..read more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into new.....read more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs,.....read more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for commercial.....read more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short Sighted..read more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, but.....read more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in about.....read more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target mitochondria..read more

Recent Blog Posts

  • Posted by AlexMuller
    Scientists probe Neptune's depths to reveal secrets of icy.....read more
    Posted by AlexMuller
    New terahertz imaging approach could speed up skin cancer.....read more
    Posted by AlexMuller
    Rebutting the claim that antidepressants do not work..read more
    Posted by AlexMuller
    Artificial neural networks decode brain activity during.....read more
    Posted by AlexMuller
    Four Earth-sized planets detected orbiting the nearest.....read more

Login to your Account

Login to your PlanetTech Account here

Username:
Password:
Remember me
or

Create a New Account

You just need username and password

The following errors occured:
Username:
Email:
Password:
Verify password:
Remember me