Major television network affiliates in metropolitan areas most affected by a record-breaking heat wave in June failed to discuss how climate change exacerbates such heat waves or mention that it will make them more frequent in the future, and major national TV networks neglected to report on the connection too. Over eight days in late June, major TV affiliates in Phoenix and Las Vegas aired a combined 433 broadcasts that included a segment or weathercast about the heat wave, but only one of those mentioned climate change -- and that one downplayed its impact. The local affiliates also ignored a new study that found one-third of the global population already faces deadly heat waves for at least 20 days a year due to climate change, yet they aired segments focused on how climate change could affect the flavor of coffee.

Phoenix and Las Vegas affiliates ignored alarming study about climate change’s impact on extreme heat, despite experiencing a record heat wave

For more than a week in late June, much of the Southwest was hit by a brutal heat wave. In Phoenix, temperatures were 10 to 15 degrees above average and new temperature records were set for three days in a row from June 19 to 21, reaching as high as 119 degrees. Dozens of flights had to be canceled after higher temperatures made it harder for certain types of small planes to take off. Las Vegas saw similar record-breaking daily temperatures and tied its all-time high temperature record of 117 degrees on June 20.

The heat wave overlapped with the publication of an alarming new study on June 19 in the journal Nature Climate Change that found that, because of climate change, almost a third of the world’s population faces deadly heat waves at least 20 days a year -- and that more than twice that percentage could experience the same by 2100. In his article on the study’s findings, Seth Borenstein of The Associated Press connected the study to the heat wave in the Southwest:

Deadly heat waves like the one now broiling the American West are bigger killers than previously thought and they are going to grow more frequent, according to a new comprehensive study of fatal heat conditions. Still, those stretches may be less lethal in the future, as people become accustomed to them.

A team of researchers examined 1,949 deadly heat waves from around the world since 1980 to look for trends, define when heat is so severe it kills and forecast the future. They found that nearly one in three people now experience 20 days a year when the heat reaches deadly levels. But the study predicts that up to three in four people worldwide will endure that kind of heat by the end of the century, if global warming continues unabated.

Yet despite having ample reason to take note, regional media ignored this dramatic study during the heat wave. Media Matters examined news coverage on the Phoenix and Las Vegas network affiliates of ABC, CBS, NBC, and FOX over an eight-day period that spanned the hottest days of the heat wave for those cities, from June 17 to June 24.

We found that the network affiliates did not air a single mention of the study -- but many of them found time to air segments on a different study published on the same day that found that climate change could lower the quality of Ethiopian coffee. In Phoenix, ABC affiliate KNXV and CBS affiliate KPHO both aired a segment about the coffee study, and in Las Vegas, NBC affiliate KSNV and FOX affiliate KVVU both aired a segment on the coffee study, while ABC affiliate KTNV aired three segments devoted to it. This focus reinforced the mistaken idea that climate change directly affects faraway developing countries, like Ethiopia, but not the U.S.  

In a June 27 post, Ron Meador of MinnPost’s Earth Journal expressed surprise that regional media coverage of the heat wave neglected to mention the Nature Climate Change study, writing (italics original):

But it is questionable whether [the heat wave of 2017] will really be one for the history books, driven as it was by climate factors that continue to progress in ways that will likely make many a future hot spell considerably worse.

This was not an aspect that came in for much discussion in regional media last week so far as I could tell. I was surprised, for example, to see no mention at all of last week’s marquee findings about the likely surge in deadly heat days over the rest of this century.

Who knows why? Maybe it’s too controversial, still. Maybe it’s considered bad taste to mention this before the instant suffering subsides. Or maybe most people understand and accept this hard truth already, which would seem to be reasonable, wise and unlikely.

Phoenix and Las Vegas affiliate stations also failed to mention global warming’s impact on heat waves generally -- and in one instance downplayed the connection 

The heat wave afflicting the Southwest was the sort of previously rare extreme phenomenon that global warming is making more common. As Pacific Standard magazine explained:

The atmospheric culprit for the heat is a very intense high pressure, which is itself setting records. Though the statistical databases show this high of high pressure to be an approximately one-in-200-year event, these events have been occurring more often lately—with the last one happening just last year. In short, the background signal of global warming makes the entire atmosphere thinner and less dense, supporting stronger high-pressure centers like the one camped out over Arizona this week, which then tend to get stuck in place—cranking up the thermostat over a multi-state region.

And Arizona State University professor David Sailor explained in an interview with The New York Times that climate change amplifies and exacerbates heat waves and can create a vicious “feedback loop” between climate change and local heat thanks to increased energy consumption:

A spike in temperature across the Southwest has left many in Arizona gasping for breath.

[...]

David Sailor, a professor at Arizona State University and the director of its Urban Climate Research Center, said that such heat waves were to be expected in the summer, but that climate change amplified such spikes in temperature.

“The science is showing that the likelihood and the magnitude of these heat waves is likely to be exacerbated by climate change,” he said.

He also emphasized the connection between what he called “global drivers of local weather” and the weather itself.

“When you have these heat waves, the residents in the area of course are using more air-conditioning than they would otherwise,” he said. “So there’s a lot more waste heat being dumped into the environment from their attempts to keep their buildings cool. That creates a kind of positive feedback loop between local heat and global climate change.”

Yet over the eight-day time period Media Matters examined, none of the network affiliates based in Phoenix or Las Vegas explained that climate change exacerbates heat waves.

Las Vegas affiliates did not connect heat waves to climate change in any of their 241 broadcasts on the heat wave. KTNV (ABC), KLAS (CBS), KSNV (NBC), and KVVU (FOX) aired 65, 54, 65, and 57 broadcasts, respectively, that included a segment or weathercast about the heat wave. None of them discussed the relationship between climate change and worsening heat waves.

Coverage on Arizona affiliates featured a single instance of a journalist connecting the heat waves to climate -- and that was to downplay climate change’s influence. KNXV (ABC), KPHO (CBS), KPNX (NBC), and KSAZ (FOX) aired 45, 53, 36, and 58 broadcasts, respectively, that included a segment or weathercast about the heat wave. Yet in all those broadcasts, climate change was brought up only once, in a June 21 broadcast on KPNX in which chief weather forecaster James Quiñones reported on record temperatures and then downplayed the impact of climate change and misled viewers by stating, “In June of 2017, we got 119 [degrees] and June of 2013 we also had 119 degrees, too, so we’re slowly warming up. And if anybody wonders, ‘Oh, is it global warming, climate change?’ Here’s the bottom line is: Ever since the last Ice Age ended about 40,000 years ago, we’ve been warming. Ever since then. So we’re continuing-- and the Earth goes through these cycles where we cool and we warm, and that’s what we are right now. We’re on a warming trend.”

Among national nightly news shows, PBS NewsHour was the sole program to discuss the relationship between climate change and heat waves

The major national networks’ nightly news programs also failed to provide context about climate change when they reported on the Southwest heat wave. There were a combined 13 segments or weather reports about the heat wave on ABC (6), CBS (5), and NBC (2), yet none made a reference to climate change.

PBS NewsHour, in contrast, aired a June 21 segment about the heat wave that directly connected it to climate change, referenced the Nature Climate Change study, and featured an interview with climate scientist Radley Horton, who explained, “If we look at the last decade or two, we are seeing twice as many record-breaking extreme heat events.”

Methodology

Media Matters searched iQ media and SnapStream for local news broadcasts in Phoenix and Las Vegas -- the two largest television markets in the region affected by the Southwest heat wave -- that included a segment about the Southwest heat wave, as well as national news segments about the heat wave, using the search terms (heat OR “heat wave” OR “heat waves” OR heatwave OR heatwaves OR temperature OR temperatures OR hot). A second search adding the term AND (“climate change” OR “global warming”) was used to identify any segments on the heat wave that mentioned climate change. We did not count teasers or rebroadcasts. Our analysis covered the time period from June 17 to June 24.

Gabby Miller contributed research to this report.