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SUMMARY:Impacts of a Disappearing Artic Sea Cover - Professor Peter Wadham
 s\, Professor of Ocean Physics and Head of the Polar Oceans Physics Group\
 ,Dept. Applied Maths and Theoretical Physics
DTSTART:20111015T180000Z
DTEND:20111015T200000Z
UID:TALK40158@talks.cam.ac.uk
CONTACT:Dr Nigel Bennee
DESCRIPTION:Professor Wadhams will explain how the sea ice cover of the Ar
 ctic Ocean has been undergoing significant changes in recent years\, culmi
 nating in the virtual collapse during this past summer when its area shran
 k to the lowest level ever recorded. This thinning of the ice layers in th
 e Arctic\, which began in 1950\, has been monitored by various techniques\
 , including satellites and upward-looking sonar from submarines and unmann
 ed vehicles in the area. The volume of the polar ice cover in summer is no
 w less than 30 percent of its value in the 1980s. The reduction of the sum
 mer sea ice cover will have some advantages\, such as easing polar navigat
 ion and oil exploration. However\, its overwhelming impact is to accelerat
 e global warming\, perhaps by a large factor. This occurs because of the a
 lbedo feedback effect by which bright\, reflective surface is replaced by 
 a dark absorptive one. This is accompanied by a further\, potentially more
  disastrous effect whereby methane\, a powerful greenhouse gas\, is releas
 ed in significant amounts from the seabed as offshore permafrost melts due
  to the warmer sea temperatures which are now made possible by the reducti
 on of the sea ice cover.
LOCATION:Wolfson Lecture Theatre\, Churchill College\, Storey's Way\, Camb
 ridge
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