What made the West explode in flames

The West’s potentially record-breaking wildfire season has burned more than 650,000 acres in California alone. Science correspondent Miles O’Brien joins Hari Sreenivasan to discuss the science behind the flames.

Read the Full Transcript

  • GWEN IFILL:

    Crews battling wildfires in California seem to have turned the corner against two of the most difficult and destructive blazes. Progress was reported in containing the Valley Fire, which erupted this weekend north of Napa Valley, which torched nearly 600 homes and left many homeless. That and a second fire have scorched more than 140,000 acres in just a matter of days, much of it exacerbated by California's continuing drought.

    Hari Sreenivasan, in our New York studio, has that.

  • HARI SREENIVASAN:

    The fires in recent days have led to the evacuation of 20,000-plus people and left some towns looking like charred ruins. Despite the progress, conditions remain unsafe in many areas. And it comes as the West is facing a potentially record-breaking fire season.

    In California alone, more than 650,000 acres have been burned by more than 7,000 wildfires.

    NewsHour science correspondent Miles O'Brien joins me from California.

    Miles, the focus has been on fires over the past few days because of all those amazing videos that we see, but really the drought is affecting pretty much everything around there.

  • MILES O’BRIEN:

    It affects every aspect of life here, Hari.

    I'm in Los Angeles, came in yesterday. They were all abuzz over a little bit of rainfall that they have had. They actually had some rain here in July, which kind of caught them by surprise. That doesn't happen here often.

    There are indications of a strong El Nino season ahead this winter, pretty strong indications. And everybody is thinking El Nino is going to save them, but it really won't. It might make a down payment, but there is also a double-edged sword component. A lot of El Nino rain after all this drought can lead to all kinds of problems, including mudslides.

  • HARI SREENIVASAN:

    When you talk about a good rain season and perhaps a good winter, how much of a dent is that likely to make in the snowpack which I saw some animations and graphics yesterday says it's the worst in 500 years?

  • MILES O’BRIEN:

    Yes. It's at a 500-year low. Some scientists looking at real data that's been collected in more modern times, and also looking at tree ring data, comparing tree rings, came up with this notion that in the Sierra Nevadas, it's at a 500-year low, the icepack, that is.

    The icepack in the Sierra Nevada, as a lot of people probably don't realize, provide one-third of the drinking water in all of California. Another third is aquifer. Another third is out of rivers and lakes and so forth. That's a very significant thing to watch. And when you hear a 500-year low, that's got to get your attention.

  • HARI SREENIVASAN:

    And when you look at the drought monitor map, you see that it's not just California. California has big streaks of very dark brown, horrible color. And then — but you go up right up the Western Seaboard, all the way into Washington, and you see sort of deep reds, where it's very dry there, too.

  • MILES O’BRIEN:

    It's a scary picture, Hari, and, unfortunately, as you project to the middle of this century ahead of us, it gets much scarier.

    We're looking at the consequences of about an almost two-degree Fahrenheit increase in temperature climatically since 1970. We're supposed to do much worse than that over the next 40, 50 years.

    And what that does is make things drier where places are drier. It actually also makes some places that are wetter wetter, too. The climate changes in some weird ways with climate change. And we have less of a snowpack. We have drier conditions for a longer period of time. We have more fires, the fires are more severe, and the fire season lasts longer.

    And then just add to that the fact that we're building homes right in the middle of these areas that are susceptible to forest fires, and you have got a big problem ahead.

  • HARI SREENIVASAN:

    Yesterday, we heard some experts and even over the past couple of days saying that the explosiveness of these fires is different because almost everything around is like kindling.

  • MILES O’BRIEN:

    It is.

    You know, a lot of this has to do with the fire management techniques and the fact that the fuel kind of builds up. But when you have a situation where you have a longer season that is drier, you make more kindling, and you also make it easier for bugs and other pests to do their work and make the trees less hardy when it comes into the face of fire.

    So there's all kinds of subtle unintended consequences that come as a result of climate change. And it does have — there's a mound of science that will tell us this is really fueling a much worse fire picture here in the West, along with a drought situation.

  • HARI SREENIVASAN:

    And finally, briefly, it looks like in the weather maps that you're bound to get a little bit of rain. That should help.

  • MILES O’BRIEN:

    A little bit of rain should help, but they need a lot of rain.

    And you have got to make sure, too, that you're not drinking from a fire hose. If you get El Nino downpours on land that is denuded and dry and devoid of a lot of foliage, that causes all kinds of problems.

  • HARI SREENIVASAN:

    All right, NewsHour science correspondent Miles O'Brien joining me from California, thanks so much.

  • MILES O’BRIEN:

    You're welcome.

Listen to this Segment