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Polar expert: climate change report “complacent”
Global warming impacts are much worse than the “outdated” IPCC assessment admits, official reviewer tells Open Knowledge.
September 25, 2013
Critics accuse the Intergovernmental Panel on Climate Change (IPCC) of overstating the effects of climate change. But Professor Peter Wadhams, veteran of 40 Polar research expeditions, takes the opposite view.
The new IPCC assessment warns that Arctic sea ice could disappear in summer by mid century. What is your assessment?
That is far too complacent. The volume of ice in the summer is going down so fast it can’t last for much longer. I think it will be gone by 2020. The predictions that say mid century are based on outdated concepts and models.
What is your assessment based on?
It is based on the observations of sea ice thickness and sea ice area and multiplying the two to get volume. The volume is diminishing so rapidly there is no way it could not go to zero very soon.
What will the climate effects be?
You will get warmer air masses in the Arctic in the summer, so that will increase the rate of melting of the Greenland ice sheet, which will result in sea level rise. It will also reduce the albedo of the planet – replacing white surfaces which reflect heat with dark water which absorbs heat.
The final effect, which might be the biggest, is this: as the sea ice disappears in summer the sea water warms up. If it is shallow water over continental shelves, the warmer water reaches the bottom and melts the offshore permafrost. That produces releases of methane which further accelerate global warming.
What is the risk from methane releases?
It is very serious. I helped write a paper for ‘Nature’ which modelled what the estimated 50 gigatons of methane that will be emitted from Arctic shelves in the next 10 years will do to the climate. It ended up adding about 0.6 degrees Celsius. That is a fairly substantial addition to the global warming from carbon dioxide.
The new IPCC report covers permafrost melting but not methane release. Is that too cautious?
It is. They are saying that the rate of melt of terrestrial permafrost will increase and we know that results in methane emissions. But they are not taking into account the possibility of large increases of methane emissions from offshore, which will in the long run have larger climate impacts.
How much will the seas rise?
By more than a meter this century. Most of the scientists working in the field estimate it should be at least a meter. If the report says anything less they are being disingenuous.
That was one of the biggest omissions of the last IPCC report. Their projection of global sea level rise was very low because they couldn’t come up with reliable figures for the rate of runoff from decaying ice sheets and glaciers. They only took account of the warming of the oceans.
To be fair, they said that people shouldn’t view this figure as being the actual total, but of course everybody did. And that has had an enormously bad effect breeding complacency.
This time they have put it right and tried to estimate what the ice sheet melt is doing.
You’ve been quite critical of the 2007 IPCC report. Why?
I did have some criticisms because it was not only cautious but incorrect. IPCC reports are always at least two years out of date because of the long gestation process of writing the report and getting consensus views.
Do you see similar problems with the latest report?
Yes, because of the unwieldy IPCC process, which I’ve been part of as a review editor. In the last meeting I went to we spent the entire time going through comments. There were 6000, a lot of them from lunatics or people with axes to grind. Yet every single one had to be answered. The result is the thrust of the report was compromised. How much do governments contribute to the IPCC process?
That’s a knotty question. We authors and review editors produce the report. Then a group of editors and government representatives massage that to produce the policymakers’ summary, a political document. They usually come up with diluted and cautious statements watering down what is actually in the original science report.
Do other climate scientists agree with your criticisms?
Most climate scientists hold the same views as me but wouldn’t utter them. Sometimes that’s because they are devoted to their work. Then there are others, especially working for government labs, who avoid saying anything because it might affect their career prospects.
What would you do differently?
The US National Ocean Atmospheric Administration publishes a ‘State of the Climate’ report every year which is very useful for up-to-date trends and results. I’d like to see a report like that, but also including some recommendations.
Would you scrap the IPCC?
It’s got a momentum of its own. It’s a bit like NATO. When the Cold War finished there was no real reason to have NATO anymore but there were so many buildings, facilities and careers that nobody dreamed of abolishing it. We can still have these doorstop IPCC reports, but insert into the process an annual review like the one NOAA produces.
“Most climate scientists hold the same views but... [some] avoid saying anything because it might affect their career prospects.”
Professor Peter Wadhams
Peter Wadhams is Professor of Ocean Physics at the Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge. He has carried out research at the Scott Polar Research Institute, Cambridge, becoming Director from 1987 to 1992. He has led more than 40 expeditions to the Arctic and Antarctic, including five voyages to the North Pole in nuclear submarines, and worked from aircraft, icebreakers and ice camps. He is a recipient of the Polar Medal and the Italgas Prize for Environmental Sciences.