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[Nagraj Adve]

 i'm not sure this will happen by 2016 - it's the most dire prediction I
have come across re Arctic sea ice - but whether it happens in 2016 or
2020, or 2025 matters little beyond the lives of those living there, and
other species. Once it happens to a significant scale beyond now, it will
affect species and humans I think throughout the Northern hemisphere and
likely beyond.
The thought of the Arctic without sea ice in summer makes me want to shout,
or cry.

Polar ice was formed as the Earth cooled slowly over time; ice in the
Antartica formed roughly 33-34 million years ago, and the Arctic about 3
million years ago. Which is why as the Earth warms due to GW, the Arctic
sea ice is going first.

Naga
Arctic expert predicts final collapse of sea ice within four years

As sea ice shrinks to record lows, Prof Peter Wadhams warns a 'global
disaster' is now unfolding in northern latitudes

   -  <http://www.facebook.com/dialog/feed?app_id=180444840287&link=http://www.guardian.co.uk/environment/2012/sep/17/arctic-collapse-sea-ice&display=popup&redirect_uri=http://static-serve.appspot.com/static/facebook-share/callback.html&show_error=false>John
   Vidal <http://www.guardian.co.uk/profile/johnvidal>,
Arctic<http://www.guardian.co.uk/world/arctic>Sunrise, 81N


   -
   - guardian.co.uk <http://www.guardian.co.uk/>, Monday 17 September 2012
   11.14 BST

 [image: Why is the sea ice in the Arctic melting?]
Prof Peter Wadhams calls for “urgent” consideration of new ideas to reduce
global temperatures. Photograph: John Mcconnico/AP

One of the world's leading ice experts has predicted the final collapse of
Arctic <http://www.guardian.co.uk/world/arctic> sea
ice<http://www.guardian.co.uk/environment/sea-ice>in summer months
within four years.

In what he calls a "global disaster" now unfolding in northern latitudes as
the sea area that freezes and melts each year shrinks to its lowest
extent<http://www.guardian.co.uk/environment/2012/sep/14/arctic-sea-ice-smallest-extent?intcmp=239>ever
recorded, Prof
Peter Wadhams of Cambridge
University<http://www.damtp.cam.ac.uk/user/pw11/>calls for "urgent"
consideration of new ideas to reduce global temperatures.

In an email to the Guardian he says: "Climate
change<http://www.guardian.co.uk/environment/climate-change>is no
longer something we can aim to do something about in a few decades'
time, and that we must not only urgently reduce CO2 emissions but must
urgently examine other ways of slowing global warming, such as the
various geoengineering
ideas<http://www.guardian.co.uk/environment/2011/dec/01/geoengineering-techniques-study-science-coalition>that
have been put forward."

These include reflecting the sun's rays back into space, making clouds
whiter and seeding the ocean with minerals to absorb more CO2.

Wadhams has spent many years collecting ice thickness data from submarines
passing below the arctic ocean. He predicted the imminent break-up of sea
ice in summer months in 2007, when the previous lowest extent of 4.17
million square kilometres was set. This year, it has unexpectedly plunged a
further 500,000 sq km to less than 3.5m sq km. "I have been predicting [the
collapse of sea ice in summer months] for many years. The main cause is
simply global warming: as the climate has warmed there has been less ice
growth during the winter and more ice melt during the summer.

"At first this didn't [get] noticed; the summer ice limits slowly shrank
back, at a rate which suggested that the ice would last another 50 years or
so. But in the end the summer melt overtook the winter growth such that the
entire ice sheet melts or breaks up during the summer months.

"This collapse, I predicted would occur in 2015-16 at which time the summer
Arctic (August to September) would become ice-free. The final collapse
towards that state is now happening and will probably be complete by those
dates".

Wadhams says the implications are "terrible". "The positives are increased
possibility of Arctic transport, increased access to Arctic offshore oil
and gas resources. The main negative is an acceleration of global warming."

"As the sea ice retreats in summer the ocean warms up (to 7C in 2011) and
this warms the seabed too. The continental shelves of the Arctic are
composed of offshore permafrost, frozen sediment left over from the last
ice age. As the water warms the permafrost melts and releases huge
quantities of trapped methane, a very powerful greenhouse gas so this will
give a big boost to global warming."