Wednesday 26th September 2012
With Professor Peter Wadhams, Head of the Polar Oceans Physics Group at Cambridge University and John Vidal (Guardian Environment correspondent) who has just returned from visiting the Arctic on a Greenpeace vessel...
The Arctic ice cap is disappearing before our eyes: this is the first large scale unmistakable impact of climate change, clearly visible from space.
The arctic sea-ice broke an all time record for lowest ever extent on Friday 24th August (after breaking several other records according to other methodologies of measurement by other scientific institutions etc…). This was a bombshell because it was nearly a month before you would expect the ice to reach its seasonal minimum – it is still decreasing now and we can expect it to continue decreasing until around mid September (so we should probably have a good idea of the absolute minimum by the time of this meeting).
What does this mean for our estimates of when the arctic will be completely ice-free at the end of the summer ?
What will be the consequences when this happens ?
How will it affect the arctic biosphere, its animals its indigenous people ?
More to the point how will it effect the rest of the world, global weather patterns and the agriculture and food supplies dependent on those ?
What about the melting of the permafrost? How fast will that happen and how much will that accelerate global warming ?
What about the methane hydrates under the arctic ocean. How suddenly might they be released ? Are we looking at apocalypse tomorrow ?
Professor Wadhams is a leading expert on sea ice. Whilst the forecasts of the IPCC for instance have been left well behind he has been at the forefront of those in the scientific community predicting a rapid disappearance of arctic sea ice. In his own words :
“For 40 years I have been measuring sea ice thickness in the Arctic from UK submarines. I first detected substantial thinning in 1990, and since the most recent submarine voyage in 2007 I have been warning that the combination of sea ice retreat and a massive amount of thinning will lead to the disappearance of the summer sea ice by as early as 2015. Despite the fact that this is a simple extrapolation of a clear and measured trend I have been vilified by scientific colleagues for making such a seemingly radical prediction. I am pleased to see these same colleagues now jumping on the bandwagon and supporting my prediction”
"What is happening is that the Arctic is warming up 3-4 times as fast as the rest of the world. The sea ice grows less thick in winter, and melts more in summer, such that the entire ice cover is now on the point of collapse. The extra open water already created by the retreating ice allows bigger waves to be generated by storms, which are sweeping away the surviving ice.It is truly the case that it will be all gone by 2015. The consequences are enormous - a huge boost to global warming from two sources, the reduction in global albedo caused by the replacement of ice by open water, and an acceleration of methane release into the atmosphere as the warm open water causes seabed permafrost to melt.
Introduction by Phil Thornhill of CCC.
Professor Peter Wadhams, Head of the Polar Oceans Physics Group at Cambridge University Questions and discussions with Professor Peter Wadhams.
Professor Peter Wadhams and John Vidal (Guardian Environment correspondent)
CCC slideshow with Phil Thornhill of CCC. Questions and discussion with John Vidal and Phil Thornhill of CCC (part1) Questions and discussion with John Vidal and Phil Thornhill of CCC (part2)
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