SACHA PFEIFFER, HOST:
It's been a record-shattering year for heat in the American West. And this weekend is going to be hot, too. If it seems like heat, drought and wildfires are all piling together, it's not your imagination. Scientists say climate change makes them more likely to happen at the same time, as NPR's Lauren Sommer reports.
LAUREN SOMMER, BYLINE: It takes a lot for heat to make headlines in Tucson, Ariz., as Stefanie Smallhouse realized listening to the radio recently.
STEFANIE SMALLHOUSE: A couple days ago, they said, well, no heat warning for today. It's only going to be 106 (laughter). Apparently, if we're not over 110, everybody should be out enjoying the weather.
SOMMER: But this year is getting people's attention, Smallhouse says. She's president of the Arizona Farm Bureau Federation, and she also runs a cattle ranch outside of Tucson.
SMALLHOUSE: In the 20 years that I've been here on the ranch, this is probably just the second time that I can remember a summer that's been so dry.
SOMMER: On top of the heat, the entire Colorado River, which is key for Arizona's water supply, has been in a 20-year drought.
SMALLHOUSE: Is there tension in the farming community right now and the ranching community? Absolutely. Is there stress? Absolutely.
SOMMER: These rare events are simply becoming more common, says Moji Sadegh, professor of civil engineering at Boise State University. In a study in the journal Science Advances, he says that trend is clear over the past few decades.
MOJI SADEGH: Basically, droughts are getting more intense, and hot years are getting more hot. And the cycle between them is intensifying.
SOMMER: Droughts and heat waves feed each other, he says. When the soil is dry, more of the sun's energy heats up the air. Then it's hotter, making more water evaporate, causing more drought. It's a climate change-driven cycle.
SADEGH: We have to move past that traditional thinking of heat waves and droughts and fires separately because they will work together. They are the reason that we are seeing so many disasters happening.
SOMMER: Disasters like the extreme fires across the West this year.
SADEGH: What is happening in California is a preview of what we'll see everywhere. We need to act now. We do not have any more minute. I'm not talking about years. We do not have any more minutes to cut our emissions.
SOMMER: Because in a hotter climate, he says, disasters are teaming up.
Lauren Sommer, NPR News. Transcript provided by NPR, Copyright NPR.
