Lennart Bengtsson: He Knows How Little We Know

  • Date: 07/05/14
  • Hans Jörg Müller, Basler Zeitung

One of the most eminent climate scientists, the Swede Lennart Bengtsson, has defected to the camp of climate sceptics. For the climate debate, this could have beneficial effects.

 «Nur teilweise verstanden»: Der schwedische Klimaforscher Lennart Bengtsson mahnt zur Besonnenheit.

“Only partially understood”: The Swedish climate scientist Lennart Bengtsson calls for prudence and moderation.

How the global climate will develop in coming years and decades, and what influence mankind has upon the climate, is a question that has been discussed with almost religious fervor until a few years ago. That is, there were no discussions really; rather, one of the two parties declared the other insane: “climate denier“ was the term used for those who were of the opinion that global warming does not take place or that it may be warming less rapidly as most scientists believed. In any case, the human impact on climate change was far from proven.

The similarity between “climate denier” and Holocaust denier was intentional: the term should insinuate that anyone who deviated from the widely prevailing consensus was a crank, possibly driven by sinister motives. Above all, very few climate sceptics were leading experts, and this was probably the alarmists’ strongest argument. While climatologists and meteorologists warned and warned, those who were becalming and moderate were often economists. As one of the leading climate sceptics, one ex-politician stood out: Nigel Lawson, Britain’s former Chancellor of the Exchequer and the chairman of the Global Warming Policy Foundation (GWPF).

Thaw 

Gradually, however, the ice seems to be melting – if not at the polar caps, then at least in the climate debates: for the first time, a widely recognized expert has changed camps. Lennart Bengtsson , the Swedish climatologist, meteorologist and former director of the Max Planck Institute for Meteorology in Hamburg, has now joined the GWPF’s academic advisory council.

After his decision was announced Bengtsson was attacked, says Lawson, which shows what kind of emotions the issue can still generate. The reason cited by the 77-year-old scientist for his decision comes in bone-dry scientific language: The relationship between greenhouse gases and global warming was “complex and only partially understood,” Bengtsson wrote in a commentary for the Swiss newspaper Neue Zürcher Zeitung.

Apart from that, all empirical observations showed that global warming has been “no serious problem up to now.” How the climate would develop in the future only model simulations could show, and these were rather “problematic”.

Nothing is settled 

Bengtsson’s conclusion: “It would be wrong to conclude from the IPCC report and similar reports that the science is settled.” Against this background, so the professor, it would be wrong to undertake any energy transition hastily.

Bengtsson’s arguments do not sound like the radicalism of old age. Rather, he exhorts his colleagues to be more prudent and empirical. For the uninitiated, this approach may be comforting, because the climate debate has long been a highly complex issue. Now, for the first time, an expert like Bengtsson admits that he and others like him fare little better: how the world’s climate will develop in coming years and decades remains pure speculation.

Translation Philipp Mueller

Basler Zeitung 7 May 2014