The Washington PostDemocracy Dies in Darkness

AccuWeather misleads on global warming and heat waves, a throwback to its past climate denial

People cool off in New York's Flushing Meadows Corona Park on July 21 during a heat wave. (Johannes Eisele/AFP/Getty Images)

A week after a punishing heat wave torched the eastern two-thirds of the country, setting numerous records, AccuWeather chief executive Joel Myers cast doubt on the scientific finding that heat waves in the United States and elsewhere are worsening because of climate change. This point of view, at odds with peer-reviewed research, is reminiscent of the contrarian position AccuWeather took on the climate change issue in the 1990s, which historical documents recently obtained by The Washington Post shine light on.

Both then and now, AccuWeather has landed on the wrong side of the science.

Myers’s essay “Throwing cold water on extreme heat hype,” published online Wednesday, attempts to debunk the scientific finding that heat waves in the United States are becoming more severe, but he cherry-picks data and shows an incomplete understanding of the drivers of temperature change.

“[A]lthough average temperatures have been higher in recent years, there is no evidence so far that extreme heat waves are becoming more common because of climate change, especially when you consider how many heat waves occurred historically compared to recent history,” Myers writes.

In saying this, he ignores the U.S. government’s National Climate Assessment, published in 2018 and signed off on by 13 federal agencies, which flat out states — with very high confidence — that the frequency of heat waves has increased since the mid-1960s.

Myers relies mostly on historical data from the 1930s to make his case that heat waves haven’t gotten worse. “Here is a fact rarely, if ever, mentioned,” he writes, “26 of the 50 states set their all-time high temperature records during the 1930s that still stand (some have since been tied).”

He concludes: “Given these numbers … it cannot be said that either the frequency or magnitude of heat waves is more common today."

But there are problems with this argument that have been addressed in the scientific literature and independent analyses.

The heat waves of the 1930s were exacerbated by land mismanagement tied to the Dust Bowl. A combination of springtime drought and farming practices left fields bare of vegetation, which allowed summer temperatures to skyrocket. In other words, the extreme heat of the 1930s is a reflection of specific circumstances in that decade and does not invalidate a link between today’s heat waves and climate change.

Zeke Hausfather, a climate scientist for Berkeley Earth, which specializes in temperature data, points out that although the heat waves in the 1930s may have had higher daytime temperatures, present-day nighttime temperatures are much higher. This is an expected outcome of climate change as the atmosphere responds to increased concentrations of greenhouse gases.

Today’s steamier nighttime temperatures allow heat stress to build, increasing the risk of heat-related illness and death for vulnerable populations without air-conditioning. So, from the standpoint of extreme nighttime temperatures, present-day heat waves are objectively far worse than those in the 1930s.

Moreover, temperature measurements in the 1930s may well have been inflated. Hausfather wrote in an email that many of those temperatures were taken on rooftops before later moving to ground stations in the same locations. Research has shown that rooftop stations tend to run warmer than their ground-based counterparts (for high temperatures). In addition, Hausfather says these historic measurements were taken using mercury thermometers which have since been replaced by new temperature sensors (thermistors), which tend to read about one degree cooler (for high temperatures).

“[O]nce the data is corrected for instrument changes, station moves, and similar factors, U.S. heat waves are actually slightly worse on average today than in the 1930s,” Hausfather said.

There’s another important point, though, that Myers is glossing over in arguing that there has been no climate change-related trend in U.S. heat waves. The heat in the United States in the 1930s was a blip compared to the cool conditions around the rest of the world, whereas today much of the world is uniformly warm, relative to the past.

The Intergovernmental Panel on Climate Change’s Fifth Assessment Report in 2013 concluded: “It is … very likely that human influence has contributed to observed global scale changes in the frequency and intensity of daily temperature extremes since the mid-20th century, and likely that human influence has more than doubled the probability of occurrence of heat waves in some locations.”

Numerous attribution studies of individual heat waves around the world have shown that human-caused climate change has made them more intense and more likely to occur. In fact, some of these studies have shown such heat waves could not have happened without a warmer world.

AccuWeather’s history of climate change doubt

Myers’s heat wave comments published last week echo statements included in a 1995 report AccuWeather, the State College, Pa.,-based forecast company, prepared on behalf of the now disbanded oil and gas industry group known as the Global Climate Coalition. Composed of oil giants such as Exxon and Shell, along with trade groups like the American Petroleum Institute, the GCC worked to spread the message that climate science was uncertain.

The group’s activities were extensively documented in the books “Merchants of Doubt,” “The Heat is On” and other reporting.

In a pre-publication copy of a February 1995 report that Myers and AccuWeather senior vice president Joe Sobel co-wrote for the GCC, they downplayed the existence, severity and seriousness of human-caused climate change.

“Put briefly, while climate does change, man’s activities do not appear to be a significant agent of change,” the report stated.

The report and other documents showing AccuWeather’s work with the GCC were provided to The Post by the Climate Investigations Center, a group that monitors organizations that “work to delay the implementation of sound energy and environmental policies” needed to address climate change, according to its website.

In addition, the report disputed other studies documenting shifts in particular extreme weather events, including heat waves, stating: “The authors have found that scientific evidence disputes the hypothesis that extreme weather events, allegedly associated with global warming, are already present. The authors are not alone in this opinion.” The report blamed the media for the perception that extreme weather events were on the rise.

AccuWeather’s report was contradicted later the same year by the IPCC, which issued its Second Assessment Report that famously found that “the balance of evidence suggests a discernible human influence on global climate.”

In that assessment, the IPCC also projected an increase in extremely hot days and a decrease in extreme cold, along with “more severe droughts and/or floods in some places and less severe droughts and/or floods in other places.”

Those projections have largely played out since then, as precipitation and temperature extremes have emerged from the background noise of natural climate variability, as indicated in the National Climate Assessment.

AccuWeather’s position on the human contribution to climate change seemed to evolve in the 2000s from a stance of doubt to acceptance. Its most recent position statement on climate change says: “Global climate change is a matter of intense concern and public importance. There can be little doubt that human beings influence the world’s climate.”

AccuWeather spokeswoman Rhonda Seaton said Myers’s essay was focused on examining “the frequency and danger of recent heat waves, not climate change or its causes,” and “should not be taken out of context.” Seaton referred to a recent Barron’s story in which Myers says that there is “no question the climate is changing and part of it is due to humans.”

However, the latest climate change assessments conclude that most if not all recent climate change is due to human activities. The Barron’s article to which Seaton refers also notes: “Myers sounded testy when asked if the weather appears to be getting more severe. The record high temperatures of the 1930s, which exacerbated the Great Depression, still stand, he pointed out.”

(The Washington Post is a customer of AccuWeather for print edition weather services.)