Matthew Cappucci:
I love that distinction you made because, really, it is summertime to your point. We will see heat domes with or without climate change. We’re always going to see heat events in the summertime. It’d be weird if we didn’t.
But what we’re noticing is the scales are tipping more towards hotter heat events and less significant cold events. So, in other words, the scale is kind of skewing towards more warm events. They’re longer in duration. They’re more intense. They’re more geographically expansive, and this sort of fits that pattern. It’s a fingerprint of climate change.
What we’re really noticing too is warm overnight lows. A warmer atmosphere is a wetter atmosphere, and so we hold more moisture, and that traps temperatures overnight. And those warm overnight lows really exacerbate heat stress.
Now, there’s one point that folks sometimes make that I find very interesting. A lot of folks say, hey, it was hotter back in the 1930s; 13 states still have all time records that have stood since the 1930s. And that’s true. But back in the ’30s, we had something called the Dust Bowl, where overfarming, inveterate drought, and incredibly hot temperatures combined to lead to this, like, insanely dry air mass that parked over the Plains for the better part of a year.
It’s easier to get hot extremes when the temperatures — or, rather, when the air mass is very dry. So back then, yes, you might have had warmer temperatures, but you’re actually getting more heat energy in the atmosphere nowadays because there’s that much more moisture in the air.
So, really, these heat events will continue getting more extreme, and especially the overnight lows are really concerning.
