Floods are getting more dangerous around the country, not just in Texas

JUANA SUMMERS, HOST:

The catastrophic floods here last week were caused by enormous rainfall. Up to 12 inches fell in a matter of hours early on July 4. Such extreme rain is getting more common because of climate change. NPR’s Rebecca Hersher is here with more. Hi there.

REBECCA HERSHER, BYLINE: Hi.

SUMMERS: So Becky, I’m here in Kerr County, which has a history of flooding, but even by local standards, this storm was extraordinary. Do we know if climate change played a role?

HERSHER: We don’t have a really clear answer yet. A preliminary analysis by a group of climate scientists in Europe estimates that the storm may have dropped slightly more rain than it would have without human-caused warming. And scientists will be able to do a more accurate analysis as more detailed data from Texas become available in the coming days and weeks. But it was an unusual storm, as you say, even for an area that gets a lot of flooding. A foot of rain in just a few hours is too much for the ground to soak it up. You know, it pools on the surface. It runs downhill. That area is hill country, so it’s like a funnel. All that water quickly gathers speed, and that’s how the Guadalupe River rose so incredibly quickly, with extraordinarily deadly results.

These floods are among the most deadly in modern history, so in that way, this disaster is exceptional. In terms of how much rain fell, how high the river got, it’s not record-breaking, but it is on par with the worst flooding ever recorded in that area. And I think it’s really notable that these types of extreme rain events, record-breaking or not, are getting more common.

SUMMERS: Help me understand that. Why would climate change cause more common extreme rain events?

HERSHER: So a warmer atmosphere can hold more moisture. So that moisture, it falls as heavy rain. And, you know, obviously humans have released a lot of planet-warming pollution into the atmosphere, so things have gotten a lot warmer. I talked to a climate scientist named Kristina Dahl about this. She works for the nonprofit group Climate Central, which makes information about climate change available to the public. And here’s what she said.

KRISTINA DAHL: Basically, the entire U.S. has seen an increase in the amount of rain falling in the heaviest events. And this latest flood in Texas is one example of what the consequences of that are.

HERSHER: So the heaviest rainstorms are dropping more rain than they used to, which is a problem because our homes and roads and bridges and emergency plans are all based on the past. Even people who know an area really well can be surprised by the weather these days.

SUMMERS: And Becky, do we know how much more rain is falling because of climate change?

HERSHER: Yeah, we actually have a rough sense. So in Texas, the heaviest storms are dropping about 20% more rain today than they were in the late 1950s, when the climate was significantly cooler. That’s according to the National Climate Assessment. And as a side note, information like that from the National Climate Assessment, it’s really hard to access right now because the Trump administration took down the website for that assessment last week. I actually have a copy downloaded on my computer. That’s how I found it.

Another thing we know from that assessment is that as the planet heats up, floods like this are causing more damage. So in the last 30 years or so, about one-third of the damage caused by inland flooding would not have happened without human-caused climate change. That’s more than $80 billion of extra damage. And that’s just damage to property. You know, you can’t put a price on hundreds of lives lost.

SUMMERS: What can be done to save lives?

HERSHER: One thing that would be really helpful is updated information about how much rain to expect, you know, taking climate change into account. A lot of the rainfall records in the U.S. are decades old, so that’s a problem as storms get rainier. The federal government is in the middle of updating those records, which could help local governments make better decisions. There are also flood warning systems — you know, sirens that can help alert people. They cost money. Most places don’t have them. And forecasts could be better, but that requires investments in research to understand rainstorms more deeply.

SUMMERS: NPR’s Rebecca Hersher, thanks, as always.

HERSHER: Thanks so much.

Copyright © 2025 NPR. All rights reserved. Visit our website terms of use and permissions pages at www.npr.org for further information.

Accuracy and availability of NPR transcripts may vary. Transcript text may be revised to correct errors or match updates to audio. Audio on npr.org may be edited after its original broadcast or publication. The authoritative record of NPR’s programming is the audio record.