ARI SHAPIRO, HOST:
President Trump has been tweeting about those California wildfires. First over the weekend he blamed bad environmental laws for the intensity of the fires, saying that clearing trees would stop fires from spreading. Then today he tweeted Governor Jerry Brown must allow the free flow of the vast amounts of water coming from the north and foolishly being diverted into the Pacific Ocean. Professor LeRoy Westerling studies climate and wildfire science at the University of California, Merced. Hi there.
LEROY WESTERLING: Hi. It's a pleasure to be here.
SHAPIRO: I want to begin by just mentioning we're hearing a sound behind you. I understand that's actually an air filter because of the smoke in the air. You're that close to one of the wildfires right now.
WESTERLING: Yeah. I live several miles from the Ferguson Fire, the one that's burning into Yosemite. The air quality here is really bad this morning. I can only see partway into my yard.
SHAPIRO: Wow. OK, well, let's start with this question of water being diverted into the Pacific Ocean. What's that a reference to?
WESTERLING: You know, that was a head scratcher for everybody here. I assumed he meant that we were keeping water in the rivers for the fish to survive there and to prevent saltwater intrusion in farmland in the delta and that somehow if we had that water available for firefighting, that we wouldn't have this problem. But even if you built a massive statewide sprinkler system and drained all of our natural water bodies to operate it, it wouldn't keep up with evaporation from warmer temperatures from climate change.
SHAPIRO: And in one of his tweets, president Trump said California must also tree clear to stop fire spreading. Would getting rid of trees stop fires from spreading?
WESTERLING: I think what he's referring to is that in the forest areas in the state, fire suppression has led to increased, you know - higher density of trees. Fires like the Carr Fire are primarily burning in grass chaparral. And so tree clearing isn't going to have a big impact on those fire risks.
SHAPIRO: California Governor Jerry Brown called these intense wildfires a new normal. Do you agree with that description?
WESTERLING: I don't actually. In climate science, you know, a normal is taking the recent experience - let's say the average of the last few decades - and using that as a guide for what the risks are that you face. And the problem is that fire is responding to climate change, and climate change is something that is going to accelerate. So there will never be a new normal.
SHAPIRO: Is there something that communities in California can do to prepare for a future in which more intense wildfires may be more frequent, more common?
WESTERLING: So we can try and harden our communities by making our structures less vulnerable to it. But the problem is that the vast majority of the homes that people live in today and will be living in for decades to come are already built. Another area where we can make an improvement is how we cluster new developments.
SHAPIRO: You're saying denser communities are more likely to be fire-safe than sprawling communities out in the forests.
WESTERLING: Yeah. And if you're going to put something - you know, a new suburban subdivision in, you could cluster the housing more and have more open space around it to have a buffer.
SHAPIRO: I'm just curious. For somebody such as yourself who you've spent your entire career studying wildfires and climate science to now have one literally so close that you cannot even see the end of your own backyard, what's this moment like for you?
WESTERLING: Well, it's a lot like last year. My entire community was evacuated in July a year ago for a week. The smoke is horrible. The smoke was horrible last year (laughter). I really could use a break.
SHAPIRO: Professor Westerling, thank you for talking with us today.
WESTERLING: Thank you.
SHAPIRO: Leroy Westerling studies wildfires at the University of California, Merced Transcript provided by NPR, Copyright NPR.