The business is over

– Why did you start studying the atmosphere?

– At Harvard, where I went, there were a lot of good students, some of them perhaps more excellent than me. I got my undergraduate degree in physics there, but I was mostly attracted to classical physics. I was more interested in it than modern physics. I stayed at Harvard for a for graduate work in applied mathematics. After 3 years, I got my doctorate. I found the most beautiful area of ​​research to be the behavior of the oceans and the atmosphere, because there were many unanswered questions. In theoretical physics, the models were stuck, but meteorology was just starting to develop. I was interested in questions such as why the wind in the tropical stratosphere blows in one direction for about one year and then in the opposite direction the next year, but I was also interested in the phenomenon of tides, atmospheric and ocean circulation, and the weather system. I continued my postdoctoral research at the University of Washington, and then at the University of Oslo in Norway. In 1965 I joined the research staff at the National Center for Atmospheric Research in Boulder, Colorado. In 1968 I accepted a faculty position at the University of Chicago, and in 1972 I accepted a professorship at Harvard University.

– When were you appointed to MIT?

– In 1982 I accepted a professorship at MIT where I remained until my retirement in 2013.

– Let’s talk about your area of ​​expertise, climate. If you had to prioritize, what factors influence Earth’s climate?

– In terms of the Earth’s major climate changes (like the glacial maximums), there are basically two spatial regions: the equatorial region and the region between the tropics and the poles, where the temperature difference depends on hydrodynamic heat transport. For changes on shorter time scales from a few years to a thousand years, the Earth has dozens of different climate regimes. For time scales ranging from thousands of years to millions of years, the temperature difference between the tropics and the polar regions has undergone profound changes, while the temperature of the tropical region has hardly changed.

– Did the equatorial region remain stable during the ice age?

– Exactly. This suggests that there are strong negative feedbacks in the radiative-flux response of the tropics. The current assumption is that small changes in the tropics are amplified at high latitudes. However, this assumption is unfounded. The difference is rather caused by the dynamics of heat transport in the atmosphere and oceans. Changes in average temperature are primarily due to changes in the difference between the tropics and the poles, not to changes in the greenhouse effect.

– What is the most significant factor influencing Earth’s climate?

– On time scales of a thousand years or less, the oceans are a major factor. The oceans are always carrying heat to and from the surface. For the dozens of climate regimes on Earth, changes in one region do not correlate with changes in another. For the major climate changes over much longer periods other factors like the orbital variations described by Milankovitch are at issue.

– Does the greenhouse effect exist and what causes it?

– The greenhouse effect is real, and is caused primarily by water vapor and clouds. Carbon dioxide, methane, and nitrous oxide are much less significant factors. Doubling carbon dioxide emissions would cause less than 1 degree Celsius of warming, compared to the 3-4 degree temperature increase assumed by the prevailing climate models. People don’t think about how small 1 degree Celsius is because some politicians are afraid that if it gets even half a degree warmer, everything will “boil down”. The UN’s Intergovernmental Panel on Climate Change (IPCC) regularly publishes long reports, running to thousands of pages. These are then summarized into general summaries, and finally the iconic one-sentence statement is born. The dominant claim has long been that most of the climate change, the warming that has been going on since the 1970s, is caused by humans. Well, even if the largest part, even all of the warming, is caused by humans, we are still only talking about a fraction of 1 degree Celsius.

– What are these models based on?

– In this regard, a study by Manabe Sukuro and Richard T. Wetherald in the 1970s provided the saving grace. Starting from a highly unrealistic one-dimensional model of the atmosphere, they found that if we assume (without any basis) that relative humidity remains constant as the atmosphere warms, it would mean a positive feedback that would double or triple the effect of carbon dioxide. This positive feedback became the basis of climate models. However, relative humidity does not remain constant. There is a principle (Le Chatelier’s principle) that natural systems resist change in the long run, meaning that the feedback must be negative.

– In the seventies, they were still warning of global cooling.

– At first, people were indeed threatened with global cooling due to sunlight reflection caused by sulfate aerosols emitted from coal-fired power plants, but there was a small problem.

– „And so?”

– That the cooling ended in the 1970s and turned into warming. In their desperation, excited politicians twisted the story a lot…

– He is credited with developing the so-called iris hypothesis. What is its essence?

– We noticed something interesting. At the top, thin clouds called cirrus (fibrous, threadlike, fluffy clouds) break out of the cumulus clouds, creating large towers of air currents. These thin clouds behave very interestingly because they are very sensitive to temperature. When it is warmer, they contract, when it is colder, they expand. Consequently, they work against greenhouse warming, that is, they act as a negative feedback.

– So this is consistent with Le Chatelier’s principle?

“Absolutely. The climate system is strongly resisting such constraints. Concerns about global warming are based on the assumption that changes in water vapor and clouds are amplifying the effect of carbon dioxide, not weakening it. But the opposite is true.

– What is the climate role of carbon dioxide?

– The Earth’s climate has undergone significant changes, but they do not show evidence that carbon dioxide is the cause. The so-called proxy data from cores drilled into the ice at the Vostok research station in Antarctica for the last 700,000 years show, despite very coarse temporal resolution, that cooling precedes carbon dioxide reduction. To prove that warming also preceded carbon dioxide increase, a higher temporal resolution would be needed. What is certain is that there is no correlation with carbon dioxide in climate changes even in the even older past. And they even forget that carbon dioxide is a necessity, but it is treated almost like a poison.

– What would happen if its concentration in the atmosphere suddenly decreased?

– If we got rid of sixty percent of the carbon dioxide in the atmosphere, we would all die. It should not be called a harmful substance, a pollutant. It is essential for plant life, without it photosynthesis would cease.

– What causes extreme weather on Earth? Climate change is blamed for the tornadoes, landslides, and forest fires we hear about every day.

– Every day, the media reports some kind of extreme event. The reality, however, is that there is no correlation, let alone a causal relationship, between climate change and extreme weather events.

– What were the consequences of decarbonization efforts?

– The US government has been committed to the current narrative since the early 1990s, significantly increasing its funding. The energy sector is one of the few sectors in which many billions of dollars are involved. Given the size of the energy sector, any attempt at restructuring, no matter how unnecessary and ineffective, has enormous potential for short-term profit. Billions of dollars have been spent on the energy transition, on transforming the energy system.

– „What did I achieve with it?”

– Carbon dioxide concentrations have not been reduced by climate policy measures. They have achieved nothing, they have not been able to prevent this alleged existential threat. Moreover, whatever we do in the EU or in the Anglo-Saxon countries will obviously have no effect on global emissions. In China and India, and everywhere outside the EU and the Anglo-Saxon countries, fossil fuels are being used and coal-fired power plants are being built. They are the main emitters today. China, India and Southeast Asia are benefiting enormously from all this. At the same time, much of Africa and South Asia are victims of the same climate policy. What they have achieved is to impoverish people and make society unstable and less resilient.

– What do you expect from President Donald Trump?

– A clear turnaround. I am no longer afraid that we will reach net zero emissions.