Feeds

New sat data shows Himalayan glaciers hardly melting at all

Results 'really were a surprise', say climate profs

Choosing a cloud hosting partner with confidence

New scientific analysis of satellite gravity measurements has shown that ice is melting from glaciers around the world much less quickly than had been thought. The new research is important as worldwide glacier melt is thought to be one of the main factors which could drive rising sea levels in future.

The new results were derived by scientists including Professor John Wahr of Colorado uni. According to the new boffinry, glaciers and ice caps in places other than Antarctica and Greenland lost only 148 billion tons of ice each year from 2003 to 2010. This is some 30 per cent lower than had been previously estimated.

In particular, it appears that glaciers in the high Asian mountain ranges - the Himalayas, the Pamir and the Tien Shan - have been losing much less ice than was previously thought. Researchers visiting the region on the ground have previously suggested that the Asian mountain ice was depleting at rates as high as 50 billion tons per year, but Wahr and his colleagues' results show losses in the area of just 4 billion tonnes annually. They give the error in this figure as plus-or-minus 20 billion tons, so this much the same as saying that the Asian mountain ice - the planet's "third pole" - was unaffected.

“The GRACE [Gravity Recovery and Climate Experiment satellites] results in this region really were a surprise,” said Wahr, in tinned quotes accompanying publication of the new research. “One possible explanation is that previous estimates were based on measurements taken primarily from some of the lower, more accessible glaciers in Asia and were extrapolated to infer the behavior of higher glaciers. But unlike the lower glaciers, many of the high glaciers would still be too cold to lose mass even in the presence of atmospheric warming.”

It had been suggested by hard-green campaigners and journalists (regrettably endorsed by the UN Intergovernmental Panel on Climate Change) that the Himalayan glaciers might disappear by the year 2035, leading to imminent drought and starvation for billions, a claim since widely rubbished. The new GRACE readings would seem to be further confirmation of that prediction's foolishness.

Climate scientists remain deeply interested in melting ice in areas away from Antarctica and Greenland as it is one of the main factors in projected global sea level rise. According to the US Environmental Protection Agency and the IPCC, the main factors driving sea level rises now are: "the expansion of ocean water caused by warmer ocean temperatures, melting of mountain glaciers and small ice caps and (to a lesser extent) melting of the Greenland Ice Sheet and the Antarctic Ice Sheet".

Thus Professor Wahr's new results are highly important, and may require future projections of sea level rise to be revised.

“One big question is how sea level rise is going to change in this century,” says Wahr's Colorado colleague Professor Tad Pfeffer. “If we could understand the physics more completely and perfect numerical models to simulate all of the processes controlling sea level - especially glacier and ice sheet changes - we would have a much better means to make predictions. But we are not quite there yet.”

The new research is published in hefty boffinry mag Nature.

Background

Sea levels have risen globally at varying rates ever since the end of the last ice age. The rate of rise has only been measured at all consistently in the last two centuries, until recent decades entirely using tide gauges. Tide gauge measurements have, however, been seriously affected by various inaccuracies (not least the fact that the land the gauges are on rises and/or falls) and tide gauges have nowadays become much more complicated to compensate. As the sea level at any location rises and falls all the time due to tides, seasons, weather etc it is necessary to take readings over long periods to identify long-term trends.

The IPCC says that "no long-term acceleration of sea level has been identified using 20th-century data alone" but says that if limited 19th-century data is included then the rate of sea level rise can be shown to have started speeding up in 1870. However, recent research on tide-gauge readings indicates that the rate of rise is steady at the 20th-century rate of 1.7mm annually, or may even be decreasing slightly.

Since the early 1990s satellites have been used to monitor global sea levels. In contrast to tide gauges they have shown a steady, unchanged rate of rise of 3.2mm annually. This line is often added to the tide-gauge record up to 1990, showing a sharp upward curve.

If the rate of sea level rise remains steady at a few millimetres annually, there is probably no need to be much concerned about it: it would take centuries to rise by amounts comparable to the variations (tide, floods etc) which occur all the time anyway. If it accelerates massively as many climate scientists believe it will, sea level rise is probably the main reason to be concerned about climate change/global warming. ®

Remote control for virtualized desktops

More from The Register

next story
FORGET the CLIMATE: FATTIES are a MUCH BIGGER problem - study
Fat guy? Drink or smoke? You're worse than a TERRORIST
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
Rosetta probot drilling DENIED: Philae has its 'LEG in the AIR'
NOT best position for scientific fulfillment
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
HUMAN DNA 'will be FOUND ON MOON' – rocking boffin Brian Cox
Crowdfund plan to stimulate Blighty's space programme
Post-pub nosh neckfiller: The MIGHTY Scotch egg
Off to the boozer? This delicacy might help mitigate the effects
I'M SO SORRY, sobs Rosetta Brit boffin in 'sexist' sexy shirt storm
'He is just being himself' says proud mum of larger-than-life physicist
NASA launches new climate model at SC14
75 days of supercomputing later ...
LIFE, JIM? Comet probot lander found 'ORGANICS' on far-off iceball
That's it for God, then – if Comet 67P has got complex molecules
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Choosing a cloud hosting partner with confidence
Download Choosing a Cloud Hosting Provider with Confidence to learn more about cloud computing - the new opportunities and new security challenges.
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.