William Nordhaus and Climate Delusions
William Nordhaus is a prominent professor of economics at Yale University. He writes extensively on climate change and its supposed economic consequences. His point of view is that of an economist who accepts official global warming theory. Nordhaus is not obviously a crackpot and that makes him unusual among promoters of global warming.
Most promoters of global warming present with signs of fanaticism. For example, the scientist James Hansen, known as the father of the global warming movement, is often arrested at protests. Hansen wants to put the heads of fossil fuel companies in jail for crimes against humanity. Naomi Oreskes, a University of California professor, sees doubters of global warming as mentally disturbed right-wing fanatics. Bill McKibben, head of the organization 350.org, thinks that the business plan of the oil companies is to wreck the Earth and that fighting global warming is the most important job that any humans have ever been entrusted with. Major environmental organizations share this fanatical point of view.
Academic economics is important and has contributed to our understanding of society. In the twentieth century large-scale economic experiments were performed in nations ranging from the USSR to Tanzania. Nations experimented with varying degrees of socialism, from total communism in Mao's China to European welfare states like Britain and Sweden. The lesson was that communism is an economic disaster and that overzealous welfare states are economically unsuccessful. Right-leaning academic economists like Friedrich Hayek and Milton Friedman predicted the outcome of these experiments before all the results were in.
Academic economics and academic climate science have in common an addiction to computer modeling of their respective complex systems. In neither case do the computer models work very well. However, no need to worry, economic models can't predict the future, as evidenced by the fact that few economists are billionaires. The weakness of climate models is obvious and well known. Different climate models give different predictions of the future and the detailed climate of the models bears little resemblance to the detailed climate exhibited by the Earth.
Computer models can be interesting and instructive, but it is an error to take them too seriously and to blindly use them to prescribe government policy. When models are presented as predictors of the future and used to give credibility to political agendas, the models are being used as propaganda tools to promote a political point of view. A complex model can be manipulated to output any desired result by adjusting the many coefficients that are always present. The modelers don't have to deliberately cook the results for political purposes. Bias creeps in as the many uncertainties are resolved in configuring the model. At the end of the process the modeler is persuaded that his "objective" model supports his previously existing point of view.
Nordhaus has written a series of books on global warming. The most recent is The Climate Casino. The title implies that we are gambling with the future of the Earth because we are changing the climate by burning fossil fuels. Nordhaus has a computer model of the Earth's economy. He calls it Dice. That name furthers the theme that we are gambling with the Earth. The trouble with his investigation is that dubious assumptions are piled on top of dubious assumptions. The conclusions are only as good as the shaky foundation of dubious assumptions. In other words, the conclusions are weak and his book, The Climate Casino, is mainly a mathematical game with limited relevance to the real world.
Players in the future of the Earth game like Nordhaus assume that increasing CO2 and increasing temperature will have a harmful economic effect. The methods they use to arrive at this conclusion are speculative. One method used by Nordhaus in a 2006 paper is to correlate economic productivity with temperature over the surface of the Earth. Since the rich countries are concentrated in the temperate zones this leads one to the dubious conclusion that temperature is economic destiny. The existence of rich countries in the tropics, for example Singapore, casts doubt on this methodology.
A beneficial consequence of increasing CO2 in the atmosphere is increased plant growth and decreased plant water requirements. Plants breathe CO2 and they have a hard time extracting it from the atmosphere. The process of breathing CO2 results in a loss of water. The fertilization effect of CO2 is solidly grounded in many experiments. CO2 generators are routinely placed in commercial greenhouses to enhance plant growth. Doubling CO2 in the atmosphere should increase world crop productivity by around 30%. For developed countries a 30% increase in agricultural productivity will increase total economic output by less than 1%, reflecting the minor contribution of agriculture to economic output. A one-time increase of 30% in agricultural productivity is minor compared to the miracles of agricultural technology that increased corn yield in the U.S. from 25 bushels per acre in 1935 to 150 bushels per acre currently.
Nordhaus runs his model for 6 scenarios, 5 involving various CO2 control schemes and one do-nothing scenario that results in increasing levels of CO2 and increasing Earth temperature. Amazingly, all the scenarios give the same per capita consumption for the inhabitants of the Earth after 90 years. It seems that the economic damage from controlling carbon is as bad as the economic damage caused by global warming. Nordhaus is up front about this. He makes it clear that the economic damages from unconstrained global warming are very small because modern economies have the means to deal with them.
Nordhaus on economics is elegant and informative. When Nordhaus writes about climate science, he sadly makes many errors and generally takes as gospel all the catastrophic claims, including claims that have fallen out of fashion among the scientist promoters of global warming. He thinks that the Gulf Stream is driven by the thermohaline circulation (sinking of cold salty water in certain arctic areas). He says this:
"A second important singularity is change in ocean currents, particularly the Atlantic thermohaline circulation, popularly known as the Gulf Stream." (Kindle Location 871 in The Climate Casino)
But the Gulf Stream is actually driven by the prevailing winds that are determined by the arctic-equator temperature differential and the rotation of the Earth. He attributes mild winters in Europe to the Gulf Stream, but the main reason for those mild winters is the moderating effect of the ocean and prevailing westerlies that bring warmth extracted from the ocean in the winter. The same effect gives Seattle mild winters without any Gulf Stream.
Nordhaus goes to some trouble to define "scientific consensus" as the collective judgement of the community of informed and knowledgeable scientists. He assumes that such a consensus exists concerning global warming. The problem is that no such consensus exists and there is, instead, a vigorous debate. Any discussion of scientific consensus should take into account science funding. Global warming has turned into a gigantic honey pot for many academic disciplines, including economics. Nordhaus cites studies of the National Academy of Sciences as if that organization is a source of objective wisdom. The National Academy of Science should be called the National Science Lobby. It promotes science funding. That is its objective and its reports and studies further that objective.
Nordhaus cites the reproduction of the 20th century temperature history by the Intergovernmental Panel on Climate Change, using an ensemble of climate models, as proof that the warming of the late 20th century was human-caused and that the models are sound. That particular demonstration qualifies as a hoax and has been heavily criticized by scientists. The demonstration was cooked to look good, by using different inputs for different models in the ensemble, to ensure a collective fit to the 20th century.
Nordhaus seems to be at home when talking economics. But he goes along with the dominant culture of bad science and exaggerated stories of doom that are typical among the global warming promoters. In his academic world he would be blacklisted if he asked too many embarrassing questions about global warming. So, he doesn't bother looking deeper into what can be fairly described as the global warming hoax.