Many people move without realizing the danger that wildfires pose to their new home. A new risk rating system could help buyers learn more on real estate sites.

Transcript

A MARTINEZ, HOST:

Climate change doesn't often come up in the home-buying process. For decades, people have been able to look up flood risks. But for wildfires, they're mostly in the dark. But that is changing starting today. NPR's Lauren Sommer reports.

LAUREN SOMMER, BYLINE: In 1991, Tom Grossman got a pretty tough assignment. He was on a search and rescue team that was called in when the Oakland Hills fire destroyed more than 3,000 homes.

TOM GROSSMAN: It looks like a war zone, right? It's flattened. Everything is burned.

SOMMER: He and his team combed the rubble for human remains. In all, 25 people died in the fire. Fast forward to two decades later and Grossman found himself looking for a new home in the Oakland Hills.

GROSSMAN: You're buying a house around here, you're in a bidding war. So we put bids on multiple houses and lost all of them.

SOMMER: But they got lucky.

GROSSMAN: This is our house up here in the Oakland Hills.

SOMMER: His home is on a steep hillside covered in trees. And it's only a few miles from where the Oakland Hills fire burned, a connection Grossman didn't make at the time.

GROSSMAN: Oh, we totally didn't make that connection. We were just going, oh, my God, another freaking bidding war.

KELLY POHL: Most folks don't know very much about their wildfire risk when they're thinking about buying a home or moving.

SOMMER: Kelly Pohl is associate director of Headwaters Economics, a land use think tank. She says homeowners can only find out their wildfire risk if it's been mapped and only a handful of states have done that.

POHL: It's definitely a patchwork. Some communities have that level of mapping, but very few do.

SOMMER: On a national scale, the federal government has mapped flood risk for more than 50 years. But its wildfire maps aren't detailed enough to be used for individual properties. Now the private sector is making those maps.

MATTHEW EBY: This will be the first look that the country has at property specific risk from wildfire. And the results are going to be surprising for some folks, to say the least.

SOMMER: Matthew Eby is executive director of First Street Foundation, a nonprofit climate research group. His team ran complex computer models to map the wildfire risk for houses in the lower 48. Satellite imagery helped them figure out what the vegetation and roof materials look like. And then they calculated how that risk will change over the next 30 years as the climate gets hotter.

EBY: And what we see is that in some areas, that risk will double, triple, quadruple. And in areas that really have high levels of risk already, like California, we see almost a 50% increase.

SOMMER: Their map show that 20% of homes are at risk. That information will be shown on home listings at realtor.com and eventually other real estate websites. Eby says the hope is that seeing wildfire info on the same page as remodeled kitchen photos will help buyers understand how climate change could affect the biggest purchase of their lives. That may not dissuade all buyers. There is a national housing shortage. But Kelly Pohl says, it could still be valuable.

POHL: We're not going to be able to stop all wildfires. And we already live in these places that have a lot of risk. So we need to think about how we can become better fire-adapted and build our homes and communities safer.

SOMMER: There's a lot homeowners can do to reduce the chance their house will burn, like cutting back flammable vegetation or changing a roof to be fire resistant. In the Oakland Hills, that's something Tom Grossman has been working on.

(SOUNDBITE OF GRAVEL CRUNCHING)

SOMMER: He put gravel down around his house where wood mulch used to be.

GROSSMAN: We used to think, wow, plants, vegetation, trees. No, it's all fuel.

SOMMER: He's also trying to help his neighbors with their homes because the first step in making the whole neighborhood safer is knowing about the risk in the first place.

Lauren Sommer, NPR News.

(SOUNDBITE OF THOSE WHO RIDE WITH GIANTS' "THE MOUNTAIN SEED") Transcript provided by NPR, Copyright NPR.