German Climatologist on Criticism of IPCC: 'We Received a Kick in the Pants'

Part 2: 'We Are Very Much in the Dark'

Photo Gallery: 'A Planetary Experiment with an Unknown Outcome' Photos
DPA

SPIEGEL: Is Germany more likely to be among the winners or the losers?

Schellnhuber: It's hard to say. We are currently working on a comprehensive study of this issue in Potsdam. Unfortunately, there are still many unknowns. Climate impact research still lags behind the rest of climate research by about a decade. The following example illustrates how complex all of this is: On the surface, warmer temperatures are fantastic for tourism along the North Sea and the Baltic Sea. On the other hand, the beaches there will first have to survive the rise in sea levels. And that's not a trivial matter. In Hawaii, one-third of beaches are already threatened by flooding. So do the advantages outweigh the drawbacks? We don't know yet.

SPIEGEL: Apparently it's just as hard to predict whether there will be more and stronger hurricanes in the future.

Schellnhuber: It's true that it is still unclear whether they will increase in frequency. A few studies do note that wind speeds in tropical storms could increase. But given that climate research is still in its adolescent phase, the next study could reach precisely the opposite conclusion.

SPIEGEL: The computer models come to more obvious conclusions with regard to storms in our moderate latitudes. Outside the tropics, hardly anything will change. Germany, according to the models, will see neither more nor more powerful storms, although the storm paths of low-pressure zones are likely to shift.

Schellnhuber: Yes, I know that my colleagues at the Max Planck Institute for Meteorology (MPI-M) in Hamburg gave the all-clear signal after doing their simulation. But this is a preliminary result at best. Personally, I don't believe that there will be no changes in storms in a world that's, say, five degrees Celsius warmer. That would greatly surprise me, given that it's such a non-linear phenomenon.

SPIEGEL: But the public has gained the impression that superstorms with previously unheard of destructive power will devastate our cities in the future. Shouldn't climatologists at least make it clear that they are still largely in the dark?

Schellnhuber: The simple answer is yes. In fact, we are very much in the dark on this issue. On the other hand, that fact is by no means reassuring. Do we really want to embark on a planetary experiment with an unknown outcome? Do we want to simply allow climate change to happen and then calmly observe the storms to see whether or not they're actually getting worse?

SPIEGEL: Was it generally a mistake not to have done more to point out the serious gaps that still exist in climate research?

Schellnhuber: Once again, all I can say is that we shouldn't adopt a bunker mentality, especially in climatology. Instead, all the doubts should be clearly and candidly addressed at conferences, even when it's painful. Just think how passionately Heisenberg, Bohr and Einstein used to argue about the fundamental aspects of quantum theory. But that was a small, manageable group of physicists who respected each other and constantly met in person…

SPIEGEL: …and global politics wasn't an issue.

Schellnhuber: Exactly! In climatology, it would be difficult, even just from a technical point of view, to conduct the entire scientific debate in full public view. That's because politicians and society want the clearest, most unambiguous answers possible. And if we can't provide those answers, many people simply stop listening to us. They're basically saying: Don't bother us with your models and counter-models. Get back to us when you have all the answers.

SPIEGEL: Is that also the reason why there are some exaggerations in the summary of the IPCC report for political decision-makers?

Schellnhuber: They're not exaggerations, but a condensing of information. We scientists can't exactly slam tens of thousands of pages of scientific articles onto the table in front of parliaments and governments. Of course the results are condensed, but that doesn't mean they're not true. However, in the interest of scientific accuracy, perhaps we could abandon the overarching goal of the IPCC report, which is to deliver summary answers to all questions about the climate -- and sometimes just say nothing.

SPIEGEL: Isn't there also a risk that studies could be suppressed if they were likely to give a boost to skeptics of anthropogenic climate change?

Schellnhuber: Believe it or not, I don't practice self-censorship, and as a physicist, I'm accustomed to recognizing that new studies might correct my point of view, even if this translates into intellectual defeat. I wouldn't hesitate to tell the chancellor that there is a new study that suggests we are all backing the wrong horse and that humans are not to blame for climate change. Or perhaps we'll discover in 20 years' time that we can easily master a five-degree increase in global temperatures. I would be very happy about that. But from today's perspective there is no reason for such optimism.

SPIEGEL: You are fighting to limit global warming to two degrees Celsius. But it's already almost one degree warmer today than it was at the beginning of industrialization. Because of the greenhouse gases already circulating in the atmosphere, another increase in temperature by 0.6 degrees can no longer be avoided. And more than 30 gigatons of CO2 are still being emitted into the air every year. Isn't the two-degree target completely unrealistic?

Schellnhuber: Technically speaking it's probably still just about possible. But in 10 years' time it'll probably be too late. After that, it could be that the only solution will be global carbon management, that is, the artificial removal of CO2 from the atmosphere, perhaps through reforestation of degraded areas of land or the direct filtration and permanent disposal of carbon dioxide. That's the ace up our sleeve, which we would then have to play. Incidentally, I'm convinced that in the long term we should take the atmosphere back to the cooler state that prevailed in the Neolithic Age, when humans became sedentary.

SPIEGEL: What do you mean? It seems hubristic to assume we can simply program average temperatures on the planet, as if we were dealing with an air-conditioning system. Do you really believe that human civilization will collapse if the temperature rises by more than two degrees Celsius?

Schellnhuber: First of all, what's hubristic here is the way we are unscrupulously interfering with creation by burning all the fossil fuels. And of course the world won't end if temperatures go up by 2.01 degrees, let alone end suddenly. From today's scientific perspective, we could possibly live with a warming of two to three degrees. But that range should be the extent of it, because greater increases in temperature would trigger uncontrollable processes, leading to sudden and irreversible changes in ice sheets and continental ecosystems. The overwhelming majority of climatologists assume that a global temperature rise of four degrees would be an immensely dangerous route that we should avoid at all costs.

SPIEGEL: Why then have you, as one of the creators of the two-degree target, imposed such a magical limit to which all countries must slavishly adhere?

Schellnhuber: Politicians like to have clear targets, and a simple number is easier to handle than a complex temperature range. Besides, it was important to introduce a quantitative orientation in the first place, which the 1992 Framework Convention on Climate Change managed to elegantly wangle its way out of. And let's be honest: Even if we aim for the two-degree target, we'll end up somewhat higher. Whenever there's a speed limit, most drivers tend to go a little faster.

SPIEGEL: At the climate summit in Copenhagen, the prevailing impression was that the most important countries don't want any fixed rules at all.

Schellnhuber: It's true that the big picture remains unclear. For the time being, there will certainly be no substantial treaty among all 194 signatories to the convention. That's why we have to pin our hopes on smaller alliances for now, such as between the European Union and Brazil. What's happening in Brazil is unbelievable. In 20 or 30 years, they could meet all of their energy needs from renewable resources. Perhaps we'll all be driving with sustainable biofuel from Brazil soon. And such bilateral projects will certainly help set the unwieldy behemoth that is the global climate treaty into motion.

SPIEGEL: Which countries do you believe are best suited to bringing about a total rebuilding of industrial society?

Schellnhuber: Ultimately only democratic societies will be able to master this challenge, notwithstanding their torturous decision-marking processes. But to get there perhaps we'll need innovative refinement of our democratic institutions. I could imagine assigning 10 percent of all seats in parliament to ombudsmen who represent only the interests of future generations.

SPIEGEL: Mr. Schellnhuber, thank you for this interview.

Interview conducted by Olaf Stampf and Gerald Traufetter

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1. Is CO2 the only cause of warming?
billryan 08/18/2010
A climatologist writes at length about the problems of global warming, but the only solution presented is a system of taxing industry and rebuilding the world industry. Not one word about the recent activity of the sun, we have had a very unusual condition. The lack of sunspots in 2008, made it a century-level year in terms of solar quiet. Remarkably, sunspot counts for 2009 have dropped even lower. As of March 31st, there were no sunspots on 78 of the year's 90 days to date (87%). The lack of solar activity and the resulting changes in the upper levels of our atmosphere may be a cause of the solar warming. No political actions punishing the evil industries will have any effect on solar warming.
2. What really matters is the scientific method
GeraldoLino 08/18/2010
The kernel of all this stuff is related to a simple application of the scientific method to the anthropogenic warming hypothesis. The hypothesis is that Mankind is affecting the climate dynamics with its carbon emissions released since the 18th century Industrial Revolution. In order to corroborate it there would have to be at least some perceivable and conspicuous changes in the evolution of certain climate parameters like temperatures, or climate-influenced factors like the sea level, as compared to their behaviour before the Industrial Revolution, in such a way that the human interference could be clearly identified. Such conspicuous index of change would be the long sought after “smoking gun” of the anthropogenic hypothesis. On to the facts: according to the 2007 IPCC report (AR4), the average atmospheric temperature has increased 0.8 degree centigrade, and the sea level has raised 0.2 m since 1870. Well, it happens that during the Holocene, the 12,000 years-old geological epoch in which our Civilization has existed, there have been several periods hotter than the current one and sea levels also higher than the current ones. For example, during the Middle Holocene, some 5,000-6,000 years ago, the sea levels were 3 to 4 meters higher than the current ones, while the average temperatures were at least 2 degrees centigrade higher, as indicated by hundreds of researches carried out in dozens of countries and in all continents. Also, the temperature rise since 1870 means a rising rate of 0.06 degree centigrade per decade, one order of magnitude lower than the warming transition to the Holocene 12,000 years ago, when the temperatures raised 6-8 degrees centigrade in less than a century. Well, dung and firewood were the only fuels used by Mankind during the Middle Holocene. If there were higher temperatures and sea levels then, and if the global warming was much faster 12,000 years ago, hence it is simply not possible to distinguish the little variations occurred since the late 19th century from the much wider natural oscillations that happened before. The only conclusion arising from these facts is that the anthropogenic hypothesis has no basis in the real world evidences, remaining a mere fabrication from mathematical models. As a corollary, any proposal of changing the entire energy structure of the world economy, which is 80% dependent from fossil fuels, can only be regarded as preposterous (or motivated by something different from the real science).
3.
BTraven 08/23/2010
---Quote (Originally by GeraldoLino)--- The kernel of all this stuff is related to a simple application of the scientific method to the anthropogenic warming hypothesis. The hypothesis is that Mankind is affecting the climate dynamics with its carbon emissions released since the 18th century Industrial Revolution. In order to corroborate it there would have to be at least some perceivable and conspicuous changes in the evolution of certain climate parameters like temperatures, or climate-influenced factors like the sea level, as compared to their behaviour before the Industrial Revolution, in such a way that the human interference could be clearly identified. Such conspicuous index of change would be the long sought after “smoking gun” of the anthropogenic hypothesis. On to the facts: according to the 2007 IPCC report (AR4), the average atmospheric temperature has increased 0.8 degree centigrade, and the sea level has raised 0.2 m since 1870. Well, it happens that during the Holocene, the 12,000 years-old geological epoch in which our Civilization has existed, there have been several periods hotter than the current one and sea levels also higher than the current ones. For example, during the Middle Holocene, some 5,000-6,000 years ago, the sea levels were 3 to 4 meters higher than the current ones, while the average temperatures were at least 2 degrees centigrade higher, as indicated by hundreds of researches carried out in dozens of countries and in all continents. Also, the temperature rise since 1870 means a rising rate of 0.06 degree centigrade per decade, one order of magnitude lower than the warming transition to the Holocene 12,000 years ago, when the temperatures raised 6-8 degrees centigrade in less than a century. Well, dung and firewood were the only fuels used by Mankind during the Middle Holocene. If there were higher temperatures and sea levels then, and if the global warming was much faster 12,000 years ago, hence it is simply not possible to distinguish the little variations occurred since the late 19th century from the much wider natural oscillations that happened before. The only conclusion arising from these facts is that the anthropogenic hypothesis has no basis in the real world evidences, remaining a mere fabrication from mathematical models. As a corollary, any proposal of changing the entire energy structure of the world economy, which is 80% dependent from fossil fuels, can only be regarded as preposterous (or motivated by something different from the real science). ---End Quote--- Please, inform me, which civilisation lived during the Middle Holecene. Were it forced to relocate its cities because of the rising water level of the oceans? It makes no sense to claim that there was a time when it had been much worse when nobody was affected. It sounds a bit nerdy to resort to such examples.
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About Hans Joachim Schellnhuber

DBU
Physicist Hans Joachim Schellnhuber, 60, is a world famous physicist and climate researcher. After working in Germany and California, he was appointed founding director of the Potsdam Institute for Climate Impact Research (PIK) in 1991, which he still leads today. He is an adviser to German Chancellor Angela Merkel on climate-related issues as chair of the German Advisory Council on Global Change (WBGU).


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