RAY SUAREZ, HOST:
Firefighters in Southern California continue to battle the deadly Thomas Fire. It's now considered the biggest wildfire in California's modern history. Until recently, fires weren't a big problem in the winter in California, but scientists say the fire season is getting longer and more destructive. Here's California Governor Jerry Brown earlier this month.
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JERRY BROWN: This is the new normal. And this could be something that happens every year or every few years. It happens to some degree. It's just more intense, more widespread. And we're about ready to have firefighting at Christmas.
SUAREZ: We wanted to know whether these more frequent and more deadly wildfires are the new normal and whether there's anything that can be done about it. We're joined by Glen MacDonald. He's a professor of geography and environment at UCLA and joins us now. Welcome.
GLEN MACDONALD: Thank you very much. It's a pleasure to speak with you.
SUAREZ: December's been a brutal month in terms of major destructive fires in California. What's happening in the atmosphere, in the ground, in the vegetation to make it so?
MACDONALD: Well, unfortunately, for us, this year, both here in the south and in Northern California, we had all the right components put together - the right recipe for a perfect firestorm. We had pretty good rainfall this last winter. That produced a lot of fine fuel. We're talking about pretty vibrant growth of our annual grasses - leaves, twigs, things like that. And not only did we not have any rainfall, but we were having record high temperatures. We saw record high summer temperatures in the bay area up north. And here, in October, for example, we had record breaking temperatures in Southern California.
And then the kind of, you know, roll of the dice was we had ignition sources when we were having very high Diablo winds up in Northern California. And we have very high Santa Ana winds down here, which is, of course, been one of the mechanisms pushing the Thomas Fire. And so just by climate and by happenstance when ignition occurred and the winds were there, we've had perfect firestorms both here and in Northern California.
SUAREZ: What can we expect moving forward, both in the near term and the longer term?
MACDONALD: Well, since the 20 top fires in terms of, let's say, structures destroyed, we found that about 13 of these have occurred since the year 2000. So something's going on here. You have to remember that our firefighting for wildland fires is much more sophisticated than it was, for instance, during the '70s. And yet we are breaking the records in this new century - the 21st century.
The other thing that I draw your attention to is California's temperatures. You don't see much trend in our rainfall for the last 100, 115 years or so. But you do see a trend in our temperatures, and temperatures have gone up on a statewide average. So we've been getting warmer and warmer. That warming means we have a longer summer season. You know, the warm temperatures persist longer into the winter. And so we have a hotter and longer period to dry out those fuels. And that's being driven by this long-term trend of increasing temperatures.
SUAREZ: If you watch California on TV, like most Americans, you're used to seeing beautiful landscapes with a house here and a house over there on the next hillside. And firefighters struggle to try to save dwellings in, really, what's very rural land. But yet we saw the shocking images from Santa Rosa - foundations, smokestacks - all that's left of house after house after house. What was different? What was going on in a densely populated, densely built area?
MACDONALD: That neighborhood is in what's considered a kind of wildland-urban fringe, but it's over 5 miles away from what the state of California would map as a high-fire severity region. So the buildings there - they were built like typical suburban housing built in the '80s and '90s. They were what you would find in the middle of a suburban zone, not what you would find out in the urban-wildland hinterland.
And if you look at the pattern of what happened, there was basically hopscotching from one burning structure to another burning structure to another burning structure. And so what we're seeing there is very hot structural fires, which are then basically igniting the structure next to them. This could happen any place. You get high winds, lots of embers, you know, continuous source of ignition coming into these neighborhoods. Sparks and embers get sucked into attic spaces, fall on dry decking, on eaves, and you begin a firestorm like we saw there.
SUAREZ: Can we engineer our way out of the worst of this, or is the bigger problem the fact that California's hotter and drier? Does that have to be addressed first?
MACDONALD: Well, this is a suite of problems that are facing the state. As climate change takes grip over the 21st century, we become hotter. And even if we don't have any change in our rainfall, we will become drier because of evaporation. Are there engineering solutions? To a certain degree, there are, certainly, in terms of the building materials that you use, the defensible space around houses both in suburbs and in the urban-wildland-fringe areas. Will they be cheap? Not necessarily. Will they maybe restrict where people can live? Possibly.
So there are fixes. I don't think all of us are going to up and leave the state of California. Fire has been a part of this state and of this landscape from time immemorial, but that will be exacerbated as the climate continues to warm. And we'll have to look at both engineering and, I think, policy and land-use planning solutions.
SUAREZ: Glen MacDonald is a professor of geography at UCLA. Thanks so much for speaking with us.
MACDONALD: It's been my pleasure. Thank you.
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