Hello, and welcome to the first edition of Record High, a limited-run newsletter about extreme heat. I’m Jake, a reporter here at Grist, and for the rest of the summer my colleagues and I will be exploring all the nasty things that happen when the mercury rises.
When climate reporters talk about global warming, we often warn readers that the earth’s temperature might rise by 1.5 or 2 degrees Celsius over the course of this century. That might not sound like a lot in human terms—you wouldn’t notice if the temperature in your living room went up by that much—but just one degree of global warming makes local heat waves much worse and much more frequent. Climate change dries out the soil and heats up ambient air, and it may even slow down the jet stream that circulates the globe. All these shifts make it easier for high-pressure air systems to develop over land. These high-pressure systems create devastating hot spells on the ground.
That’s what happened in the Pacific Northwest during the summer of 2021, when a “heat dome” pushed temperatures into the triple digits for almost a week, killing scores of people. In later “attribution” studies, scientists found that climate change made the disaster hundreds of times more likely, and they’ve reached a similar conclusion in more than 90 percent of other heat wave studies since 2000, according to an analysis from Carbon Brief. Researchers estimate that another 1 degree Celsius (1.8 degrees Fahrenheit) of warming could turn the Pacific Northwest heat dome into a once-in-a-decade affair.
“You can be confident that heat waves are increasing everywhere globally due to climate change,” Sarah Kew, a climate researcher at the Royal Netherlands Meteorological Institute, told my colleague Joseph Winters this week.
Indeed, many deadly heat waves from the past decade would have been statistically impossible if human beings hadn’t polluted the earth with carbon. More than any other disaster, we can say with scientific confidence that climate change is the sole cause of the deaths that occur during events like Japan’s 2018 hot spell. The Pacific Northwest heat wave is now the subject of a lawsuit against Big Oil by one Oregon county.
But spells of extreme heat also make other climate disasters more frequent and more dangerous. Marine heat waves, which have become more common over the past decade, may contribute to stronger hurricanes, and high heat is also a key ingredient in tornadoes and severe thunderstorms that cause lethal flooding. In other parts of the world, heat waves often exacerbate drought, drying out earth and plants by increasing “evaporative demand,” and a drier landscape can lead to more wildfires.
This past week saw the two hottest days in recorded history, and already this year there have been deadly heat waves in India, Mexico, and the U.S. South. This is all happening even before the reemergence of the El Niño climate pattern, which will raise global temperatures even further over the coming year. These heat waves endanger young children, elderly people, and outdoor workers, and they also threaten key infrastructure like roads and power lines.
To learn more about the science behind extreme heat, click here to read Joseph’s full story. And keep an eye on your inbox for next week’s issue of Record High.
By the numbers
The average global temperature on Tuesday, July 4, the hottest day in recorded history.
What we’re reading
A new heat record: Tuesday, July 4 was the hottest day in recorded history, surpassing a record set the previous day. Grist’s Max Graham breaks down the grim milestone.
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Heatwaves cause increased flaring: Texas oil and gas operators flared and vented hundreds of thousands of tons of methane gas during this month’s heat wave, according to Inside Climate News. The flaring will contribute to the buildup of greenhouse gases in the atmosphere.
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Protecting farm workers from deadly heat: A nurse in Florida is educating farm workers to listen to their bodies while on the job, in an effort to teach workers to recognize early signs of heat stroke and heat exhaustion, the Washington Post reports.
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How renewables bailed out Texas’s grid: Texas Monthly writes that record solar power generation may have saved the Lone Star State’s troubled energy grid during a recent episode of extreme heat. The state’s ample solar and wind infrastructure helped meet record demand even as coal and gas plants faced outages.
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