For years he promulgated the IPCC’s key message. Now, the former environment senator and manager Fritz Vahrenholt has had a change of heart. In this interview, he explains his change of opinion.
In his new book “The Cold Sun. Why the climate catastrophe will not happen,” Professor Fritz Vahrenholt, former environment senator and CEO of RWE Innogy, outlines his thesis that global warming will be significantly less substantial than previously thought. By the end of the century, he believes, there will be just an increase of one degree Celsius. The influence of the sun on the Earth’s climate, however, has been significantly underestimated until now.
Welt Online: You have supported the IPCC’s paradigm for many years. Now you are publishing a book in which you questioned the doctrine of global climate change. How did this change of heart happen?
Vahrenholt: Yes, I was an active supporter of the CO2 theory. But then I had two pivotal moments that have inspired me to reassess my position.
First, I was invited in February 2010 as a scientific reviewer for the IPCC report on renewable energy in Washington. There, I realized that the drafting of the report was done in anything but a scientific manner. The report is littered with errors. At the end, representatives of Greenpeace edited the final version. The result was the nonsensical claim that 80 percent of total world energy needs can be met with renewable energy.
These developments shocked me. I thought, if such things can happen in this report, then they might happen in other IPCC reports too. Of the 34 members of the IPCC Secretariat, the bulk are from the global South – such as Cuba, Sudan, Madagascar, Iran or China. These countries all have an interest in transfer payments. Until then, I had thought researchers would meet and discuss. No, in fact these are delegates representing nation states – and not always democratic ones. They represent interests and exert influence.
Welt Online: And the second key experience?
Vahrenholt: At RWE Innogy, we were confronted with the fact that the wind and the corresponding power generation were dipping by an appreciable extent. I investigated this phenomenon scientifically and found that it has nothing to do with CO2 and global warming, but that natural climate processes are responsible for it. The activity of the sun plays a major role. I have been working on the subject matter and then worked a year on this book.
Welt Online: You talked about delegates who meet at UN meetings. But scientists in Germany and elsewhere are still mostly convinced that mankind is largely responsible for climate change trough the emission of CO2.
Vahrenholt: But these scientists are not asked what the final report text looks like. They are merely quoted. And there is tremendous pressure on scientists to conform to the mainstream. If you fail to do so, then you will no longer receive any funding or you will be excluded from conferences and talks. This happened to myself. The University of Osnabrück has excluded me from an invited lecture because I have written this book. Dissenting opinions are no longer allowed.
Welt Online: On what scientific basis does your criticism of the majority opinion rest?
Vahrenholt: I am not a climatologist, of course, but I work in the same way as the IPCC. I look at thousands of scientific publications on the topic. In my book I also provide a forum to those whose publications that have been removed by the shortening of the IPCC’s final report. The so-called Core Writing Team of the IPCC, which selects the material according to policy objectives, is made up to 30 percent of people who are affiliated with Greenpeace and the WWF. I had not known that fact previously.
Welt Online: What are the core substantive findings that have prompted your changing of position?
Vahrenholt: I was previously unaware of the fact that CO2 is a greenhouse gas with a relatively modest impact. Only by means of positive feedback effects do people arrive at a catastrophic scenario. The influence of the sun on our climate has been generally underestimated until now. At this point, you simply have to start thinking anew. My book is indeed an anti-IPCC-book, but I do not put myself against scientists who, overall, do worthy and important research. But it is not the scientists who claim ‘if you do not do this and that by the year 2020, the world will plunge into chaos.’
Welt Online: So you do not deny that CO2 contributes to global warming?
Vahrenholt: It has undoubtedly made a contribution, but to a very much lower degree than previously thought. The IPCC says that 95 percent of the current warming comes from CO2 and other greenhouse gases. By comparison with the evolution of the climate of the past 2000 years, we come to the conclusion that the sun has a much stronger influence. In the 20th century, not only has the concentration of CO2 in the atmosphere increased, but also the radiation and the magnetic field of the sun.
I cannot say exactly whether the contribution of CO2 to global warming makes up 40, 50 or 60 percent. However, both factors play a role, and the influence of the sun is probably even a little stronger than that of CO2.
Welt Online: How do arrive at this estimate?
Vahrenholt: We have experienced a warming of 0.8 degrees Celsius since the end of the Little Ice Age. This is primarily due to the large millennial climate cycle in which the Earth warms in each of the first 200 years of the cycle. Between 1970 and 2000 there is a sharp increase in the average temperature, but the same rate of increase was also observed between 1910 and 1940 and between 1860 and 1880.
This is nothing extraodinary. If you look closely, you can see that this change is connected with a 60-year cycle of global ocean currents. The Pacific Decadal Oscillation (PDO) has an influence on the temperature of the earth. In 1977, the PDO entered in a positive phase. It was at the maximum at the turn of the millennium, and is now in a downturn. The Atlantic Decadal Oscillation is also in decline, a little bit delayed.
A part of the warming is thus due to natural effects. The decisive shortcoming of the IPCC is that the warming from 1977 to 2000 was seen as due to CO2 and simply extrapolated to 2100 in the climate models. Another problem is that the importance of soot was underestimated. Soot has about 55 percent of the climate effects of CO2 predicted by the IPC. Also, at this point, CO2 must therefore give up some of its former role as the key driver of global warming.
We note that global temperatures have plateaued for the last twelve years. The explanations of the climatologists are not enough to explain why there is a pause. The Pacific and Atlantic Oscillations are still not taken into account in their models.
Welt Online: Will it become even colder soon?
Vahrenholt: First of all, the small solar cycles – the Gleissberg and the Suess cycles – are in a downturn phase. Secondly, the decadal oscillations will be in their negative phase for the next 30 years. And thirdly, we have one of the weakest solar cycles in 80 years. It could be that the next solar cycle will be even weaker.
All this led us to the the conclusion that we are facing a so-called Dalton Minimum, a cool period, as it was the case from 1790 to 1830. Warming of the climate, which is caused undoubtedly by CO2 and other greenhouse gases, will be offset by other natural effects to a considerable extent in coming years and decades. The bottom line is that we will only have global warming of only one degree by 2100 – provided that the cycles will continue to behave the way they did for the past 7,000 years.
Welt Online: But climate scientists warn that the concentration of CO2 in the atmosphere has reached such a level that the natural regulatory processes, of which you speak, may not even work anymore. If that is true, we would have a problem, not?
Vahrenholt: The sun cannot be influenced by the CO2 in the atmosphere, neither can the stratosphere. The increase in carbon dioxide from 0.028 percent to 0.038 percent in the atmosphere is nothing earth shattering, after all. Most people do not know that CO2 is only considered so significant because its climate impact is amplified by water vapor. When the temperatures rise due to CO2, so the argument goes, then the concentration of water vapor in the atmosphere also increses. This additional greenhouse gas contributes much more to the greenhouse effect than CO2.
But fortunately, there are feedbacks that are acting in a correcting way. More water vapor means more clouds. And clouds shield the radiation from the sun. I believe that Mother Nature is a fairly stable system, otherwise we would have turned into a hot, waterless planet like Venus a long time ago in our long geological history.
Welt Online: In otrher words, we can simply sit back and forget about climate change. Mother Nature will take care of it.
Vahrenholt: No, not at all; I didn’t say that. Even a one degree increase in temperature is already quite substantial. This corresponds to the climatic difference between Hamburg and Freiburg. Even if we do not have to fear any increase of two, three or four degrees, there are good reasons to continue with an energy policy which aims at reducing emissions of CO2 and at developing renewable energies – not least for reasons of energy security.
Research should be intensified. The good sun gives us further 30 years to do it in a rational way. But we do not have to put tens of thousands of megawatts photovoltaic on roofs and in the countryside by 2020. This aberration is only due to a consideration which got out of control. There is fear and hysteria, which caused many people to think that if climate change is so dramatically bad, then we need to pay some eight billion euros a year to fight it.
My message is: we can and should make the effort to use renewable energy sources where they are really efficient – for example in southern Europe or in North Africa. We do not need to rebuild our whole energy system in this country in the next ten years, hysterically and under pressure.
Welt Online: The share of natural gas in electricity generation will increase globally. Experts warn that more methane will get into the atmosphere through leaks. As methane has a much bigger impact on climate than CO2, an entirely new situation could be arising.
Vahrenholt: That’s correct. By focusing on CO2, we have neglected other factors such as methane or carbon black so far.
Welt Online: Do you deal with the topic methane in your book?
Vahrenholt: No, I don’t, because there are as yet no definitive figures. There is indeed a great need for research.
Welt Online: In Germany, the government has decided on an ‘energy transformation.’ Do you hope that your book will cause a course correction?
Vahrenholt: The ‘energy transformation’ is more like a huge construction site now, but without any cranes. In order to make it happen, we would need a massive network expansion and a large storage capacity for electrical energy. I do not see how that could be enforced in the near future against popular resistance. In Germany today we have a capacity of 25,000 megawatts photovoltaic and 29,000 megawatts of wind power. Yet these energy sources are very volatile.
There are days when it is virtually impossible to generate wind or solar power – sometimes neither of them generates any energy. To compensate for this, we are going to need conventional power plants in the next 50 years. But for now, we are driving full speed into a wall. The energy revolution will not work if we believe we can do without fossil fuels in the near future.
New fossil power plants are the ideal partner for renewable energy sources because they can be quickly powered up and shut down. We must not rush into renewables. The sun gives us a respite. After reading my book thoroughly, Mrs. Merkel could say: “We have been quite lucky!”
Welt Online: What is your assessment of the current risk for power blackouts in Germany?
Vahrenholt: Someone who should know, the outgoing president of the Federal Network Agency, has said that we are dancing on a razor blade. A cold spell, as the one we have now, means the alarm level is high. The Czechs and the French, from whom we import electricity, now need their own energy – for heating their own homes. Currently, we are meeting our demand for imports with help of an oil-fired power plant in Austria.
Let us hope that in the next two weeks, given the freezing cold, nothing will go wrong. If Mr. Röttgen says that solar energy reduces the likelihood of blackouts, this only shows how ignorant this man is. The maximum power demand in winter is in the early evening, when solar power generation has dropped to zero.
Translation Philipp Mueller