Jan-Gunnar Winther is director of the Norwegian Polar Institute, Norway's central institution for research, environmental monitoring and mapping of the polar regions.
He was speaking to EurActiv editor Frédéric Simon.
When you look at the 2007 IPCC assessment and the current state of scientific knowledge on climate change, what difference do you see?
When the IPCC reported in 2007, it said there would be approximately a 5cm sea-level rise resulting from Greenland ice melt by the end of this century. Now, the research done after that indicates that it could be three times higher as the ice flows faster in Greenland, delivering icebergs to the ocean. So it is more likely that we will get a 14cm sea-level rise this century from Greenland ice melt.
What is the current state of knowledge on temperature increases?
The IPCC in its 2007 report states that we will see a 1.5 to 6°C temperature change by the end of the century. That is a wide range and it is way different if you get one or the other. But it is more and more likely that we will end up at around +2°C or +3°C this century, which is also a big number.
So why do we think this is man-made, in addition to natural? Well, one reason is that if you run the climate models without CO2 and other greenhouse gases, they will reconstruct climate variations fairly well until around 1970. After 1970, the observations and the models will not do very well if man-made release of greenhouse gases are not included in the model. If you include them, the models are reconstructed, they follow observations much better.
Another point is the rapidity of the increase in CO2 over the last 14,000 years, which is at least twenty times higher than what we have had at any other moment in time. So it is a very different pattern that we have today compared with what we have had earlier under natural situations.
You said earlier that CO2 and temperatures closely follow each other but that you are not quite sure which one comes first. Can you elaborate on this?
In parallel data that we obtain from ice cores and sediments, the resolution of the information gets poorer and poorer the further you go back in time.
So while we have very high annual resolution for recent years, the data gets poorer as we go back in time. There are uncertainties when you get a change in CO2 and temperatures 10,000 years back in time. So to then to establish a proof is difficult – you have evidence but not proof. But the physical correlations between the two are very very strong.
What has happened in the last decades is that CO2 has increased way above what we have had in the past. And temperatures have increased but not as dramatically as CO2 - so far less than 1°C in the last hundred years.
So the figures on the table on Copenhagen are not the right ones?
I wouldn't say that it is not the right figures. We have a platform of knowledge which is the IPCC 2007 assessment, and there is always dynamics in new results, they will come in all the time.
We need to make a thorough assessment again before we have a new platform. So yes, it is the right numbers. But results tend to underscore that we have a more rapid loss of ice, at least from Greenland.
What about Antarctica? Some studies suggest that the continent was for the first time contributing to sea-level rises. Can you explain that?
Yes, for a long time we have thought that Antarctica would in fact increase in mass because high temperatures give more precipitation and when it is very cold, that transforms into ice or snow. That has been the general understanding. But then in the last ten years, we had losses around the coastal areas that have been quite rapid and dramatic. And the question has focused on what the net balance is for the whole ice sheet. And a more recent survey from this year indicates that we have a net loss of ice from Antarctica.
Are the consequences of climate change already being felt here in the Arctic Circle in Norway?
Absolutely, the Arctic in particular is the area where things are changing very, very fast - maybe the fastest. And the one parameter that is changing the most and is visible for sailors is Arctic sea ice, which has been decreasing rapidly and much more rapidly than the models that have been projected. In the recent past, we had five consecutive years of minimal sea-ice extent.
At the same time, public opinion does not always follow science and may not believe that the situation is alarming…
That is correct. In Norway, there is 50% of the population who think there is no man-made climate change and the other 50% who think there is. And this is despite the fact that 95 to 97% of climate researchers believe there is a combination of natural variations and an anthropogenic element as well that is causing climate change.
That worries me because the general public are also voters.
Why do you think there such scepticism?
It is difficult to feel those relatively slow changes with our own bodies. If you visit the Arctic and come back ten years later, you will see a glacier that has retreated. But year-on-year, you don't always feel those changes. And also, in a place like Norway, there are benefits from a warmer climate, we have richer agriculture and forestry, we also have richer fisheries, we have a more decent climate, so people are not seeing this as only negative.
There are also economic opportunities for Norway with melting ice in the Arctic…
Yes, for many countries, with melting sea ice, you have an opening of sea routes from Asia over to Europe that offer an economic potential.
In the last few years, we have had totally open or partly open North-West passages and North-East passages. This year, the first non-Russian commercial ship, a German ship, sailed through the North-East passage and I think the same company is planning to harbour six ships over here next year. If this ice retreat continues, as it might, we will have not only the straits that are open but also the Arctic Ocean. In a time perspective, we really don't know but some scientists say that this could happen in a few decades.
And that opens of course a series of issues for Norway, as an arctic coastal state related to the environment, search and rescue operations, geopolitical, etc. There are many things that are not regulated in this area.
What about prospects for access to oil and gas in the Arctic region?
Well, we have to remember that in the Arctic there are depths of 4,000 metres or more. So with today's technology, even without sea ice, there are tremendous challenges for operations there. But in areas like in the Barents Sea, with less sea ice, there may be more room available for these activities.
In Norway, there is a big political dispute about whether we should explore oil and gas in the Barents Sea. And the government has said that we will collect information on the state of knowledge before we make a decision. And you can imagine there are different views on that: there are oil companies, there are NGOs and everything in between. And the Norwegian Polar Institute will be leading this collection of knowledge that will be used for the final decision.
When you see what is going in on at the political level, with countries hesitating to make firm commitments on emissions reductions, how do you feel about that?
Well I think getting a good agreement is better than getting a not-so-good agreement. And I am a realist too, not only a scientist. I would hope for a very good agreement in Copenhagen. But if, for many reasons, that is not possible - and I understand that this is a very complex issue politically speaking - I think we should not be too depressed because we have to work continuously to find this good agreement. And that should happen and needs to happen quickly. But it is not like it is Copenhagen or nothing.
There is enough evidence based on the IPCC 2007 report on consequences that are so serious that politicians have enough information for decisions to be made.
Are you optimistic or pessimistic about the planet's future?
I think we will cope with it. Even if you are not an idealist, for us as humanity, it will cost less to fix the problem than not fixing it. The cost of inaction on global warming is greater than the cost of action.
It is not too late, the situation is not black and white, but the longer we wait, the steeper the temperatures will continue to increase and the consequences should be larger. So it is important to act rapidly but there is no such thing as an absolute limit where you have to act or not.
So there is no point of no return?
No, I don't see it like that. I think it is very helpful to have actions and it is more helpful to have them earlier rather than later.