It’s hot — Now you know what to blame

Complaining about the weather is as American as apple pie and baking at a baseball game, but we’ve never had anything to blame. Now, thanks to advances in climate science, we can say on any given day how much climate change boosted the odds of your ice cream cone melting in your lap.

Fans of the Houston Astros, Arizona Diamondbacks, Atlanta Braves and the Wilmington Blue Rocks all experienced at least one day last week in which climate change boosted the odds of sweltering temperatures by a factor of two or more. That means that the thickening blanket of greenhouse gasses wrapped around our planet has doubled or even tripled the frequency of those temperatures.

But last week, the impact of climate change was even more apparent at night. Every major league baseball team experienced at least one night last week with nighttime temperatures that had a detectable climate fingerprint. For 80 percent of the continental U.S. and 81 percent of Americans, at least one night had warm temperatures that were at least twice as likely due to climate change. And over a huge area of the country containing 35 percent of Americans, people experienced nighttime temperatures that were at least five times more likely. This area extends outward from Arizona and another zone stretching from Texas to Florida and northward to Indiana and Ohio.

If it seems to you like summer nights typically don’t cool down the way you remember, it’s not your memory. They don’t. If you live in a house or apartment with air conditioning, you’re paying a higher price for a healthy night’s sleep. For people without air conditioning, or who can’t afford to run it, the price can be even higher. Hot nights exacerbate health problems like asthma and heart disease, and for some people, they can be deadly. Animals and plants are feeling the impacts, too. Higher nighttime temperatures can reduce yields in some crops and they can cause soils to release more heat-trapping carbon dioxide into the atmosphere.

The statistics from last week come from my organization Climate Central’s new tool the Climate Shift Index. Every day, we put a number on how climate change has (and sometimes hasn’t) contributed to daily high and low temperatures. The Climate Shift Index gives us a new way of seeing how climate change is impacting weather in the U.S. And, as one early reviewer noted, it gives us “a radical new way to complain about the weather.” 

As the heat of summer 2022 builds, the Climate Shift Index will give Americans not just a new way to complain about the weather, but a more specific way. At least for the coming decades, climate change will bear more and more of the blame for higher and higher temperatures. 

Weather is inevitable, but climate change is not. While there might not be much that governments can do to change the weather, stopping the planet from warming is another story.

Burning fossil fuels releases pollutants into the atmosphere, and one of these pollutants — carbon dioxide — is the major driver of warming in the day and at night. As long as carbon pollution continues, the planet will get hotter, and heat like today’s and tonight’s will happen more and more often. But if emissions stop, so will the warming. That means policymakers ultimately control the world’s thermostat.

The Climate Shift Index gives us a daily look at how that thermostat is being managed. It’s still cranked way up, and we’re feeling the effects today. And we can expect more and more of these days until governments and companies meet the commitments that they’ve made to reduce carbon emissions and to stop turning the thermostat up each year.

Andrew Pershing is the director of Climate Science at Climate Central. He is an expert on how climate trends and events impact ecosystems and people and recently led the Oceans and Marine Resources chapter of the fourth U.S. National Climate Assessment. Follow him on Twitter: @Sci_Officer