A delicate academic matter has disrupted the climate science community: One of the most respected climatologists, Emeritus Max Planck Director Lennart Bengtsson, has switched to the camp of climate sceptics. In this SPIEGEL ONLINE interview he explains his surprising decision.
One of the most renowned climatologists has changed sides. Lennart Bengtsson, former director of the Max Planck Institute for Meteorology in Hamburg, one of the world’s leading climate research centres, has joined the Academic Advisory Council of the Global Warming Policy Foundation (GWPF)…
Bengtsson has always been known for his moderate viewpoints during the hot climate debates of the 1990s. In a SPIEGEL ONLINE interview, he explained his move into the camp of skeptics.
About the person
The meteorologist Lennart Bengtsson, born in 1935, was director of the European Centre for Medium-Range Weather Forecasts from 1981 to 1990, then director of the Max Planck Institute for Meteorology in Hamburg, one of the world’s leading climate research centers. Since his retirement in 2000, he has worked as a professor at the University of Reading in England. He has been given many awards, among them the German Environmental Award of the Federal Foundation for the Environment. He has dealt mainly with the modeling of climate and weather.
SPIEGEL ONLINE: Mr. Bengtsson, why have you joined the climate sceptic Global Warming Policy Foundation?
Bengtsson: I think it is important to enable a broad debate on energy and climate. We urgently need to explore realistic ways to address the scientific, technical and economic challenges in solving the energy problems of the world and the associated environmental problems.
SPIEGEL ONLINE: Why do you think the lobby (sic) group GWPF is particularly suitable?
Bengtsson: Most members of the GWPF’s Academic Advisory Council are economists, and this is a chance for me to learn from some of these highly qualified experts in areas outside my own expertise. I want to contribute there through my meteorological knowledge to open the debate.
SPIEGEL ONLINE: But the people at GWPF do not have the reputation of reconsidering their opinions. Have you also become a so-called climate sceptic?
Bengtsson: I have always been a skeptic, and I think that is what most scientists really are.
SPIEGEL ONLINE: But were you not one of the alarmists 20 years ago? Do you think your position at that time was wrong?
Bengtsson: I have not fundamentally changed my opinion in this area. And I have never considered myself an alarmist, but as a scientist with a critical eye. In this sense, I have always been a skeptic. I have used most of my career to develop models for predicting the weather. I have learned the importance of forecasting validation, i.e. the verification of predictions with respect to what has really happened. So I am a friend of climate forecasts. But the review of model results is important in order to ensure their credibility.
SPIEGEL ONLINE: And here you see a demand for climate research?
Bengtsson: It is frustrating that climate science is not able to validate their simulations correctly. The warming of the Earth has been much weaker since the end of the 20th century compared to what climate models show.
SPIEGEL ONLINE: But the IPCC report discusses these problems in detail.
Bengtsson: Yes, but it does not do so sufficiently critical. I have great respect for the scientific work that goes into the IPCC reports. But I see no need for the endeavor of the IPCC to achieve a consensus. I think it is essential that there are areas of society where a consensus cannot be enforced. Especially in an area like the climate system, which is incompletely understood, a consensus is meaningless.
SPIEGEL ONLINE: You complain about the strong tendencies towards politicisation in climate research. Why do you join now a political (sic) organisation?
Bengtsson: I was fascinated my whole life by predictions and frustrated by our inability to make forecasts. I do not think it makes sense to think for our generation that we will solve the problems of the future – for the simply reason that we do not know future problems. Let us do a thought experiment and go back to May 1914: Let us try from the perspective of that point in time to make an action plan for the next hundred years – it would be pointless!
SPIEGEL ONLINE: Do you suggest we should carry on with business as usual just because forecasts are complicated?
Bengtsson: No, but I think the best and perhaps only sensible policy for the future is to prepare society for adaptation and change. In 25 years the world will have nine to ten billion people. This will require twice as much primary energy as today. We need to foster new science and technology. We need a more open approach, especially here in Europe, which includes the issues of nuclear energy and genetic engineering, in order to supply the growing world population with energy and food.
Translation Philipp Mueller