In Germany, the warmie community is reeling from the defection of one its major players, Fritz Vahrenholt. Venderholt is a prominent Social Democrat, a former German Environment Minister, the outgoing CEO of the renewable energy group RWE Innogy, the author of a book soon to be released, "The Cold Sun," in which he writes that the "climate catastrophe is not occurring." Recently, he was questioned about his turn to AGW heresy in Der Spiegel
SPIEGEL: You are an electric utility executive by profession. What prompted you to get involved in climatology?
Vahrenholt: In my experience as an energy expert, I learned that the Intergovernmental Panel on Climate Change (IPCC) is more of a political than a scientific body. As a rapporteur on renewable energy, I witnessed how thin the factual basis is for predictions that are made at the IPCC. In one case, a Greenpeace activist's absurd claim that 80 percent of the world's energy supply could soon be coming from renewable sources was assumed without scrutiny. This prompted me to examine the IPCC report more carefully.
SPIEGEL: And what was your conclusion?
Vahrenholt: The long version of the IPCC report does mention natural causes of climate change, like the sun and oscillating ocean currents. But they no longer appear in the summary for politicians. They were simply edited out. To this day, many decision-makers don't know that new studies have seriously questioned the dominance of CO2. CO2 alone will never cause a warming of more than 2 degrees Celsius (3.6 degrees Fahrenheit) by the end of the century. Only with the help of supposed amplification effects, especially water vapor, do the computers arrive at a drastic temperature increase. I say that global warming will remain below two degrees by the end of the century. This is an eminently political message, but it's also good news.
SPIEGEL: You make concrete statements on how much human activity contributes to climatic events and how much of a role natural factors play. Why don't you publish your prognoses in a professional journal?
Vahrenholt: Because I don't engage in my own climate research. Besides, I don't have a supercomputer in my basement. For the most part, my co-author, geologist Sebastian Lüning, and I merely summarize what scientists have published in professional journals -- just as the IPCC does. The book is also a platform for scientists who apply good arguments in diverging from the views of the IPCC. The established climate models have failed across the board because they cannot cogently explain the absence of warming.
SPIEGEL: You claim that the standstill has to do with the sun. What makes you so sure?
Vahrenholt: In terms of the climate, we have seen a cyclical up and down for the last 7,000 years, long before man began emitting CO2 into the atmosphere. There has been a warming phase every 1,000 years, including the Roman, the Medieval and the current warm periods. All of these warm periods consistently coincided with strong solar activity. In addition to this large fluctuation in activity, there is also a 210-year and an 87-year natural cycle of the sun. Ignoring these would be a serious mistake …
. . . In the second half of the 20th century, the sun was more active than it had been in more than 2,000 years. This "large solar maximum," as astronomers call it, has contributed at least as much to global warming as the greenhouse gas CO2. But the sun has been getting weaker since 2005, and it will continue to do so in the next few decades. Consequently, we can only expect cooling from the sun for now.
. . . Many scientists assume that the temperature changes by more than 1 degree Celsius for the 1,000-year cycle and by up to 0.7 degrees Celsius for the smaller cycles. Climatologists should be putting a far greater effort into finding ways to more accurately determine the effects of the sun on climate. For the IPCC and the politicians it influences, CO2 is practically the only factor. The importance of the sun for the climate is systematically underestimated, and the importance of CO2 is systematically overestimated. As a result, all climate predictions are based on the wrong underlying facts.
I don't claim that I know precisely whether the sun is responsible for a 40, 50 or 60 percent share of global warming. But it's nonsense for the IPCC to claim that the sun has nothing to do with it.
SPIEGEL: You claim that the standstill in global warming since 2000 has been caused in large part by a simultaneous decline in solar activity. But, in fact, the sun behaved relatively normally until the middle of the century, only becoming noticeably quieter after that. How does this fit together?
Vahrenholt: There are two effects: the declining solar activity, as well as the fluctuations in ocean currents, such as the 60-year Pacific oscillation, which was in a positive warm phase from 1977 to 2000 and, since 2000, has led to cooling as a result of its decline. Their contribution to the change in temperature has also been wrongly attributed to CO2. Most of all, however, the last sunspot cycle was weaker than the one before it. This is why the sun's magnetic field has continued to weaken since 2000. As a result, this magnetic field doesn't shield us against cosmic radiation quite as well, which in turn leads to stronger cloud formation and, therefore, cooling. What else has to happen before the IPCC at least mentions these relationships in its reports?
SPIEGEL: What you neglect to mention is that it hasn't been proven yet that cosmic radiation, which is shielded by the sun at varying degrees of effectiveness, truly leads to more cooling clouds on Earth. So far, it is only a hypothesis.
Vahrenholt: It's more than that. The Cloud Experiment, headed by physicist Jasper Kirkby, has been underway at the CERN particle research center near Geneva since 2006. The initial results of tests conducted in a chamber in which the earth's atmosphere was simulated showed that cosmic particles do indeed lead to the formation of aerosol particles for clouds.
SPIEGEL: But the aerosols demonstrated in the Cloud Experiment are much too small. They would have to grow before they could actually serve as condensation germs for clouds. Whether this happens in nature is still an open question. You present this as a fact.
Vahrenholt: You will find many correlations between cloud cover and cosmic radiation in the book. I'd like to know why the IPCC doesn't thoroughly examine this mechanism. My guess is that the answer to this question would jeopardize the entire foundation of the IPCC predictions.
The solar cycle is everything but normal. NASA scientists predict that this cycle will indeed be the weakest of the last 80 years. Not only did it start two years too late, but it's also very weak. And, besides, you can't just count sunspots. Cosmic particles continue to rain down on us because the sun's magnetic field is hardly shielding us.
Various American and British solar research groups believe that weak solar cycles are ahead. I take this seriously and expect only cooling from the sun until 2050.
SPIEGEL: Do you seriously believe that all 2,000 scientists involved in the IPCC are deluded or staying true to the official line?
Vahrenholt: It's not like that. However, I am critical of the role played by the handful of lead authors who take on the final editing of the report. They claim that they are using 18,000 publications evaluated by their peers. But 5,000 of them are so-called gray literature, which are not peer-reviewed sources. These mistakes come out in the end, just like the absurd claim that there will no longer be any glaciers in the Himalayas in 30 years. Such exaggerations don't surprise me. Of the 34 supposedly independent members who write the synthesis report for politicians, almost a third are associated with environmental organizations like Greenpeace or the WWF. Strange, isn't it?
SPIEGEL: Why are you taking on the role of the climate rebel with such passion? Where does this rage come from?
Vahrenholt: For years, I disseminated the hypotheses of the IPCC, and I feel duped. . . .
SPIEGEL: So, is it a mistake to concentrate exclusively on the reduction of carbon dioxide?
Vahrenholt: Yes. In addition to carbon dioxide, we also have black soot, for example. It creates 55 percent of the warming effect of CO2, but it could be filtered out with little effort within a few years, especially in emerging and developing countries. And, in doing so, we would achieve huge benefits for human health. . . .
SPIEGEL: Surveys show that fear of the climate catastrophe has declined. Are you preaching to the choir with your all-clear?
Vahrenholt: The fear mongers are still shaping the political debate. According to the German Advisory Council on Global Change, environmentally minded countries should forcibly bring about reduced consumption for the sake of protecting the climate. This takes us in the direction of an environmental dictatorship. And the fearmongering is also beginning to take effect. When I was in a restaurant recently, I overheard a woman at the next table telling her children that it's wrong to eat an Argentine steak -- because of the climate. That's when I ask myself: How could we have come to this point?