Guest essay by Dr. Richard Lindzen, MIT
A recent exchange in the Boston Globe clearly illustrated the sophistic nature of the defense of global warming alarm.
In the December 3, 2015 edition of the Boston Globe, the distinguished physicist, Freeman Dyson, had on op-ed, “Misunderstandings, questionable beliefs mar Paris climate talks.” His main point, stated immediately, is that any agreement reached in these talks would “likely do more harm than good.” In an otherwise, thoughtful commentary, however, Dyson begins with a common error. He attributes the basis for climate alarm to the United Nations Intergovernmental Panel on Climate Change (IPCC).
For reasons that I will address shortly, this is an entirely understandable error. Dyson’s description of the IPCC position is
“The IPCC believes climate change is harmful; that the science of climate change is settled and understood; that climate change is largely due to human activities, particularly the release of carbon dioxide into the atmosphere by industrial societies; and that there is an urgent need to fight climate change by reducing the emissions of carbon dioxide.”
To be sure, it would be hard to identify the ‘beliefs’ of the IPCC, but I take it that he means their position. Obviously, the IPCC does not claim that the ‘science is settled;’ that would destroy the raison raison d’être for the existence of the IPCC.
Also, insofar as the IPCC is not supposed to make policy recommendations, it does not claim “that there is an urgent need to fight climate change by reducing emissions of carbon dioxide.” That climate change is harmful is, of course, the basis for the existence of the IPCC, and is an intrinsic source of regrettable bias. The IPCC does not claim that climate change is mostly due to human activities generally; it restricts itself to the period since about 1970, which was the end of the most recent cooling period (a period which gave rise to global cooling concerns). Even the IPCC recognizes that climate change has always occurred – including a warming episode from about 1919 to 1940 that was almost identical to the warming episode from about 1978 to 1998 that the IPCC does identify with human activities. However, all the claims cited by Dyson are frequently made by politicians and environmental activists (including Ban Ki Moon, Secretary General of the UN), and the IPCC scientists never really object. Why should they? Support for climate science (a rather small backwater field) has increased from about $500 million per year to about $9 billion.
Dyson, further notes that the ice ages were major examples of climate change that we don’t fully understand, and that lacking this understanding suggests that we don’t really understand climate change. As another example of something that we don’t understand, he cites the potential role of the sun. Dyson then goes on to praise environmentalism in general, to approve of the increasing wealth of China and India, and their understandable unwillingness to forego this, and finally notes the well-known fact that CO2 is plant food whose increase has been associated with extraordinarily valuable increases in agricultural productivity.
In the December 13, 2015 Boston Globe, 8 members of the MIT faculty (three physicists, two hydrologists, one meteorologist, and two atmospheric chemists) attacked both Dyson and his claims. Their letter was entitled “So much more is understood about climate change than skeptic admits.”
They proceed to express their dismay with Dyson’s “limited understanding and short-sighted interpretation of basic elements of climate science.” There follow 3 disingenuous objections to Dyson’s scientific examples. As concerns ice ages, the MIT professors argue that they took thousands of years, allowing humans to adapt. They ignore the Dansgard-Oeschger events (episodes of dramatic change within glacial periods) which involved major changes in decades as well as the onset of the Younger Dryas (where glaciation suddenly reoccurred after the initial deglaciation of the last major glaciation) that also involved major changes setting on in decades. With respect to the sun, they argue that solar activity changes have been minor, ignoring the potential amplification due to solar impacts on cloud formation, most recently explored by Svensmark and Shaviv, but already suggested by Dickinson in the 1970’s. With respect to the role of CO2 as plant food, the letter writers appeal, without justification, to other limiting factors, ignoring that the greatest limiting factor, water, is alleviated with elevated levels of CO2. They also ignore literally hundreds of observational studies.
The letter writers then propose that ‘prospects’ in renewable energy, energy efficiency and safe and secure nuclear energy should presumably justify the abandonment of cheap, safe and available fossil fuels by developing nations. Yes, safe. Control of real pollutants is well developed already.
The letter writers go on to their only unambiguously correct claim: namely, that the IPCC does not declare that the science is settled. They then present the iconic statement if the IPCC’s Working Group 1 (the one dealing with the scientific assessment – as opposed to the remaining 2 working groups that generally begin with worst case scenarios in order to claim impacts and design mitigation strategies): “The IPCC report presents strong evidence that more than half of the climate change seen in recent decades is human-driven.” One may readily disagree with the claim of ‘strong evidence’ since the claim (based on model results) depends on the assumption that models correctly display natural internal variability which very clearly they don’t.
That said, the claim that most of the climate change since 1960 is due to human activities, refers to more than half of a change on the order of only 0.5C, and is entirely consistent with the possibility that the sensitivity is low and far from dangerous – especially since model projections for warming since 1978 have almost all exceeded what has been observed (regardless of ‘adjustments to the data). Indeed, the warming since the end of the little ice age (around 1800) of about 1C has been accompanied by improvements in virtually all measures of human welfare. Why another 1C should be considered planet threatening is rarely explained. The letter writers’ conclusion that the observed warming implies “a great risk that increasing greenhouse gases will result in future climate change with destructive consequences for humanity and the natural environment” does not follow from the iconic statement; nor is it made by the IPCC. Rather, it is, as has already been noted, the conclusion that is added by environmental activists and politicians.
A careful reading of the letter of the 8 professors leaves one wondering whether the dismay they express over Dyson’s “limited understanding and short-sighted interpretation of basic elements of climate science” is not merely a projection of their own limitations and biases.