Saturday, September 22, 2012

Professor Peter Wadhams calls for action

In the Youtube video below, Professor Peter Wadhams, Professor of Ocean Physics and Head of the Polar Ocean Physics Group of the University of Cambridge and one of the world's top sea-ice experts, joins The Big Picture, a show with Thom Hartmann filmed live and broadcast from the RT America studios in Washington DC.

Professor Wadhams warns that the Arctic sea ice looks set to be completely melted in just a few years. Professor Wadhams adds that action is needed that includes not only emissions cuts, but also geoengineering methods.

It was a Skype connection, so the sound quality was not optimal, but Peter Carter has improved this in the version below. Anyway, the message is important enough to be watched closely and to be further shared and discussed.

The diagram below illustrates this further.

more on this diagram

As the Arctic sea ice retreats, an ever smaller area remains in summer. Snow cover on the ice reflects between 80% and 90% of sunlight, while the dark ocean without ice cover reflects only 7% of the light, explains Stephen Hudson of the Norwegian Polar Institute. As the sea ice cover decreases, less solar radiation is reflected away from the surface of the Earth in a feedback effect that causes more heat to be absorbed and consequently melting to occur faster still.

The image below shows the retreat in September 2012 to date, compared with 7 other recent years.

credit: Arctic Sea Ice Blog
The image below further illustrates the rate at which Arctic sea ice is declining, and thus losing  its reflectivity.

Image produced by Peter Carter based on NSIDC images, showing the now exposed permafrost areas that extend from the continents into the shallow parts of the Arctic Ocean. 

NASA images showing the difference between sea ice cover between 1980 and 2012.

If you like, read more about this at the post Albedo change in the Arctic.

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