Most Swedes know that our country was covered by ice during the ice-ages – latest some 20 000 years ago. We know this because our lands are still “rebounding” like a spring – or a sponge - that has been compressed (except that this goes on for thousands of years). It is just a few mm per year but it gives a feeling for how mighty the forces of nature are.
That must have been a heavy load of ice! In fact when I fly in to Gothenburg I look down and think that a third of that distance was ice… Still I never compared this to Antarctica.
In the run up to the COP 21, the Collège de France has organized three large symposia. The first was the one I organized with Roger Guesnerie on the economics of climate change. The second was about how to conceive of the Anthropocene and the last was this Monday (Nov 9) on climate, energy and science led by Professor Edouard Bard in presence of the French President Hollande. During one of the talks on paleoclimate it suddenly dawned on me that this ice above us in Gothenburg was in fact like living under Antarctica. There were two big ice-caps in the north – one over North America and Greenland and another over northern Europe. Most of us have heard the difference between when the arctic ice melts (nothing much happens to sea level since it is already floating in water) and when or if the Antarctic (or Greenland ice would melt) which does raise the sea-level. The same applied of course to the ice over Scandinavia – it was sitting on land and at that time you could walk from France to Great Britain (although the place was not so Great in those days). When it melted the sea level rose by some 125 meters.
Suddenly the Antarctic and Greenland ices seem closer to heart and their melting less hypothetical. The way we are going it is in fact quite likely – just that it will be several or many hundred years off. Environmental economists have struggled to include effects 50-100 years away into economic thinking. With conventional discounting costs that are a century away, are worth nothing much – one or a few percent. One million USD 2115 would be of the order of 10 000 today (anywhere from USD 70to USD 50 000 for rates of 10 to 3%). Environmental economists have thought of all kinds of reasons for raising these values and using lower and declining discount rates. But most people stop thinking after 2100. Not even the environmental economists really talk about costs 500 years away. Yet we should. Those ice caps will melt. One of the lectures of the symposium described how complicated the calving of icebergs is. (And how strange that calving in French is the same word – or image Vélage .. a cow giving birth to a calf). And the seas will rise by tens of meters and we will lose not only the obvious Venice, London and Bangladesh – but we would presumably have a few centuries during which there were no stable coastlines at all. No point hardly in building ports and infrastructure that will be inundated in a few decades. What would that do to world trade? In his lecture Edouard Bard described his research which has shown that after the last ice-age there were periods of sea-level rise as fast as 4-5 meters per century. That rise was a response to a change in climate forcing smaller than the one implied by the 400 ppm CO2 now..
There is a certain amount of agonizing over the concept of Anthropocene. Many geologists feel uncomfortable with the somewhat loose definitions. When did it really start, what are its geo-markers? I just had a coffee with one of my new colleagues, Jean-Jacques Hublin, who is at the Collège de France and also at the Max Planck Institute for Evolutionary Anthropology. Man has been interfering with species composition for thousands of years (“the Amazon it not at all “natural wilderness” but bears the clear marks of cultivation and selection by man) and there have been effects even at the atmospheric level – particularly for methane, less so for CO2. Of course these effects have accelerated significantly in the last century but it is hard to set a particular date when the anthropocene starts.
As I am writing, Edouard Bard rushes past looking for coffee. He is in the next office to mine if he is not in the south of France. He is off to the Sorbonne, across the street to give a lecture on icebergs, he shows a beautiful picture from the calving of an ice sheet in Ilulissat, Greenland, and talks of the importance of a thousand year perspective on the anthropocene. He mentions an article that came out in Science yesterday showing unexpected and dramatic loss of ice from a glacier in Greenland and tells me of a scientific dispute about the ice cap over Scotland and how long it was connected to the cap over Ireland. I didn’t even know that the British Channel was a river at that time! – Draining the whole European continent from melting ice… He has done research on the debris from that river… and he told me that just like Scandinavia is rising after the pressure from all that ice – so land in Britain is actually receding (on balance land must sink in one place if it is to rise somewhere else) so the local rise in sea level is even faster in Britain than average - my old school, Westminster, next to the Thames, will drown faster than I thought.
In the afternoon of that symposium, economists, sociologists and anthropologists discussed . At the end there was a round table with President Hollande. There was a bit of security but less than expected and President Hollande really seemed very interested. He started with a speech (available at the website of the Elysée) but then he spoke freely and answered questions on all kinds of aspects of climate change with eloquence and on occasion he had some punch to his comments. When one social scientist said that we social scientists will always be ready to debate he gave a quick answer– “yes well I would never have doubted that.” He said he wanted to speak not just for France but for Science, and I thought not too many heads of state would do this. When he finished he walked down the steps and then set off in an angle to the corner where I was sitting at the edge of the first row and shook my hand. I was so surprised I didn’t think of anything smart to say. Then he was surrounded by others and whisked off to the next meeting while we enjoyed a wonderful Collège de France cocktail.
http://www.college-de-france.fr/site/actualites/COP21-trois-colloques-au-College-de-France.htm