Peter Wadhams

on .

(Head of the "Polar Ocean Physics Group," University of Cambridge)

Peter Wadhams ScD (born 14 May 1948), is professor of Ocean Physics, and Head of the Polar Ocean Physics Group in the Department of Applied Mathematics and Theoretical Physics, University of Cambridge. He is best known for his work on sea ice. From 1970-74 he studied for a PhD at the Scott Polar Research Institute, University of Cambridge on "The effect of a sea ice cover on ocean surface waves". Now, with more than 40 years of experience on Sea Ice studies and on Arctic ocean changes, he covers several charges on matters related to Ice melting and Climate change. In a recent interview for "The Guardian", he said that " by 2015-16, the summer Arctic (August to September) would become ice-free". What can we do to avoid this prediction? And what would be the short and long term consequences? Peter Wadhams will answer to these and other questions.
INTERVIEW - (February  2013)
The interview was realized and published in February 2013 - (Original interview in English)
Subject: Arctic Melting: causes, effetcs and solutions

1. Question: Since 1951 the temperature in Greenland has gone up by 1.5°C,  compared with around 0.7°C globally. Why Arctic is more vulnerable than other areas to climate change?

The troposphere over the Arctic is thinner than at lower latitudes, so heat retention by climatic gases warms up a smaller part of the air column. But also there is a strong albedo feedback - that is, as snow melts or sea ice retreats, the contrast in albedo between the ice/snow covered surface and the bare land or water is so great that it causes an anomalously high rise in temperature.

2. Question:
According to a NASA's study ,, since 1970 Multi-year ice (Ice that made it through at least two summers) "extent" has been diminishing at a rate of -15.1% per decade since 1980; and according to the NSIDC, in September 2012 Arctic Ice extent was at the lowest level recorded in the satellite record of 3.41 million square kilometers (1.32 million square miles). Do you think the process of Arctic Ice melting has already reached a point of no return? Are we still in time to act?

I think that the summer sea ice has reached a point of no return, and we will soon have a genuinely ice-free Arctic in August and September. We can, however, act to prevent this ice-free season from steadily lengthening until it takes up a significant part of the year.

3. Question:
In a recent interview for "The Guardian" you said: "The final collapse of ice summer will probably be complete by 2015/16”. What will be the main short and long term consequences in a local and a global scale of such a collapse and, more in general, of Arctic Ice melting? What will be the benefits?

Short term consequences include the albedo feedback effect already mentioned; a rapid release of methane in summer from the seabed over the Arctic continental shelves, because of the warming of the water, which melts offshore permafrost; and an increase in the rate of melt of the Greenland ice sheet, because of warmer air masses passing over Greenland.

4. Question:
What are the 5 main reasons why humans should act in order to stop Arctic Ice Melting?

1. To save us from the seabed methane burst which represents an acceleration of global warming.
2. To stop the retreating ice from having an impact on atmospheric flows which may be causing a change in the position of the jet stream, with serious consequences for food production in the US. 3. To slow down the melt of the Greenland ice sheet, hence the rate of global sea level rise.
4. To preserve Arctic habitats eg for polar bears and seals.
5. To save the thermohaline circ (see below). 2. 3.

5. Question:
In particular, Arctic Ice melting can cause a disruption of the mighty "overturning circulation" of the global oceans, the exchange of warm tropical and cold polar water. What will be the consequences of this phenomena?

This occurs because ice no longer forms in the Greenland Sea. The consequences will be cooling (in fact a slower rate of warming) of NW Europe, and a faster warming of the tropical Atlantic regions, including more energetic hurricanes.

6. Question:
What do you think is the main cause, among human activities, of Arctic Ice Melting?

Undoubtedly carbon dioxide emissions causing global warming.

7. Question:
It is proved that Co2 emissions are the main cause of global warming. There are many proposals to reduce such emissions: on one hand, reducing the demand for energy (Movements of decreasing, Transition towns and so on); on the other hand, restructuring the supply of energy, by turning from the traditional sources of energy (coal and Oil) to more sustainable and clear ones (wind and sun) or to nuclear ones? What do you think would be the right approach to face the problem?

Both are needed, but nuclear is likely to be most effective. Best is to use thorium.

8. Question:
What can we do to arrest the Arctic Ice melting process? In particular, what should government do and what should citizen do? There are solutions that could be put in place in a short term? Could you say the first 5 priorities human should put in place?

Citizens can do little or nothing. Governments can try geoengineering methods for temporary relief, including whitening of clouds with fine water nozzles, and release of powder aerosol into upper atmosphere.

9. Question:
What do you think about Oil extraction and trade route in the Arctic? Will they badly affect Arctic biodiversity and what can be done to limit such activities?

It is unlikely that Arctic shipping will become so prolific as to affect wildlife.

10. Question:
Finally, If you could send "a message to humans", what would you suggest to do in order to preserve themselves and our Planet in the long period?

We must urgently change our whole way of life, away from fossil fuel use, towards use of nuclear power for generating baseline electricity, electric cars, small-scale self-sufficient home energy systems. Above all, a massive effort at birth control worldwide - if we don't control our numbers voluntarily, global famine will do it for us.