Continuing University of Guelph professor Ross McKitrick’s look at Steven E. Koonin’s landmark book Unsettled: What Climate Science Tells Us, What it Doesn’t, and Why it Matters.
The middle chapters of Unsettled cut through the rhetoric around extreme weather like a tornado. It is one of the most important topics for someone like Koonin to tackle since he links important scientific information about trends in weather hazards with the glaring dysfunction of the mechanisms by which the public get informed about them. In his tour of the deceptions around climate extremes Koonin presents a series of case studies in which the media and political rhetoric is shown to be a distortion of government assessment reports, which are in turn shown to be distortions of the underlying data and research. In chapter 5 he begins by showing how evidence that the US climate has become less extreme over the past century was manipulated to support headlines claiming the opposite. The data were grossly manipulated in a misleading way, and the scientific institutions (including the National Academy of Sciences) whose job it is to stop it from happening stood silently by.
Chapter 6 opens with some insightful comments about “attribution studies” in which experts rush to the microphones after a damaging storm and claim their models show it was caused at least in part by greenhouse gases. “I’m appalled that such studies are given credence,” Koonin objects. “It’s like a spiritual adviser who claims her influence helped you win the lottery – after you’ve already won it.”
Koonin then begins his dive into the data with a discussion of a famous graph in the 2017 US Climate Science Special Report (part of the National Climate Assessment) that appears to show a dramatic increase in the rate of weather extremes in the US from the 1930s to the present. A glance at the figure appears to show an accelerating increase in record high temperatures. But later in the report another graph appears showing annual maximum temperatures in the US have declined considerably since the 1930s. How could both be correct?
Koonin enlisted University of Alabama meteorologist John Christy to get the underlying data and help figure out what was going on. Christy produced a chart showing that the incidence of record highs per year (defined as the number of US locations in each year that recorded their maximum value over the entire sample from 1895 to 2016) peaked in the 1930s then fell and thereafter had no trend over the 120 year span. But the number of locations showing a record cold temperature had declining steadily. The two together implied that the US climate was becoming less extreme.
The National Assessment graph was constructed in a different way, first by using a different definition of extremes and second by reporting the ratio (rather than the numbers) in each year of hot versus cold extremes. That last step was key. It meant that even though both hot and cold extremes were going down, since the cold extremes were going down faster, the ratio would appear to be rising. “[There] is no arguing that it is shockingly misleading” said Koonin, describing the effect of the graph.
Multiple US government agencies were involved during the report-writing phase, and many agencies had a chance to object to the deception. The National Academy of Science reviewers offered a mild and diplomatically worded protest of the overall presentation of data on extreme temperatures, but evidently did not follow up because the report got worse, not better, after the completion of expert review.
The graph in question was quickly seized upon by multiple news agencies who made it one of their key headlines. And none of the report-writing officials who knew better spoke up to correct the record. Thus the massive apparatus of government science agencies and the media bigwigs who preen constantly over their supposed commitment to the truth combined forces to mislead the public into believing that a climate system becoming less extreme over time was instead becoming more extreme and dangerous.
What else have they misled everyone on? Koonin is just getting started.
Next week: Tempest Terrors.