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Wildfires Rage Across Parts of Western U.S.

July 9, 2007 at 6:30 PM EDT

JEFFREY BROWN: A combustible mix of epic drought, searing heat, plus tinder-dry forests and grasslands has produced an early and raging fire season. Much of the western United States is affected.

The latest fire burned a stretch of the Black Hills of South Dakota. The blaze raced out of a canyon yesterday near Hot Springs, killing one local homeowner. It quickly scorched 11 square miles. Cooler temperatures and a rare rainfall have helped quell the blaze today.

The largest fire in Utah history rages across more than 460 square miles in the center of the state.

SUSAN MARZEC, Bureau of Land Management: The fire is so intense and the smoke is so intense that we’ve not been able to fly our helicopters or our planes. And with the winds, it’s made it even worse. It’s really grown; it’s really moved; it’s become a dangerous fire.

JEFFREY BROWN: Sixty miles of Interstate 15 in Utah, also a main north-south corridor through six western states, were closed Sunday because of fire. Kasey Hodges had hoped that I-15 would act as a firebreak of sorts, but the road provided no relief.

KASEY HODGES: Well, I figured, “You know what? This ain’t worth it. We need to get out of here.” Because it’s hot. It felt like somebody was holding a blow dryer to the back of your head. So we just got in the car, and we got out of here as fast as we could.

Some fires sparked by lightning

JEFFREY BROWN: Rail lines and a power plant were threatened by the blaze. Five deaths have been blamed on the fires there. Utah shopkeeper Michael Rutherford barely escaped harm. His store did not.

MICHAEL RUTHERFORD, Utah Shopkeeper: We didn't realize until we were gone how bad it really, really was. We only had about a minute to get out of here. I grabbed my change box in this hand and one handful of things and went out the door, and that was it. And it came over that hill and burned us down right to the ground.

JEFFREY BROWN: Many of the western blazes were sparked by lightning strikes, which ignited landscapes parched by years of drought, and were further fueled by recent triple-digit temperatures. Since Friday, two dozen lightning fires have raced across northern Nevada, burning 250 square miles. Fifteen hundred evacuees were allowed to return to Winnemucca today after fire destroyed an electrical substation, shut down roads, and killed livestock.

Additionally, fires burned across both Northern and Southern California: 58 square miles of the Inyo National Forest in the eastern Sierras burned over the weekend. That fire is now 55 percent contained. Sixty-five hundred acres of the Los Padres National Forest in the rural reaches of Southern California's Santa Barbara County burned on Sunday. A firefighting helicopter crashed; only minor injuries to the crew were reported.

And we take a closer look now at the conditions that set the stage for all of these wildfires with Lisa Graumlich, director of the School of Natural Resources at the University of Arizona. She's a paleo-ecologist who studies the way environments and weather patterns change over time. She joins us from Tucson.

Well, Professor Graumlich, start by telling us where things stand this summer compared to recent years, in terms of drought and fires.

Severe droughts

Lisa Graumlich
University of Arizona
The drought that we're currently in actually started in 1999 and has persisted.

LISA GRAUMLICH, Director, School of Natural Resources at University of Arizona: Well, this is actually starting to become a bit of a norm. The drought that we're currently in actually started in 1999 and has persisted. And it's been a drought that's not only been severe, but it's been very pervasive.

We're dry here in Tucson, here in the southernmost part of the western U.S., and that drought extends up not only to northern Utah, but into Montana, as well. What's interesting about this, though, is that, you know, in previous years we've had perhaps wet areas in the northern part of the U.S. and dry areas in the South or vice versa. But what we're seeing here and for the last several years is this west-wide pattern of drought.

JEFFREY BROWN: Is there a reason why the fire season started earlier this year?

LISA GRAUMLICH: We think we're starting to unravel that, and it has to do with what has been a relatively subtle change in the climate of the West. You probably heard in climate change reports that over the 20th century we have about a one-degree Celsius or about a 2.5-degrees Fahrenheit warming here in the western states, and frankly that can sound like a lot of, you know, kind of a yawn to many of your viewers. But it turns out that difference makes a huge difference in the snow pack of the West, which is so critical to governing processes like fire in our western mountains.

So what we're seeing is a reduced snow pack related to no rains coming, but also anywhere from a week to almost four weeks earlier melting off of that snow. So what happens then is that these forested lands start to dry out earlier in the spring.

What are we at here? You know, July 9th, and it's essentially as if we were in sort of early August, in terms of the amount of time that these forested landscapes have been dry and prone to the kind of circumstances, you know, whether it's a lightning strike or a human ignition, that could create wildfire.

Connections to global warming?

Lisa Graumlich
University of Arizona
[W]e know from tree-ring records that, in the mid-1100s, in sort of medieval times, we had a drought in the Colorado Basin that lasted six decades.

JEFFREY BROWN: And of course, the big question, I guess, is why? Why is this drought -- what's our current understanding of why this thing happens?

LISA GRAUMLICH: Oh, you know, that is the big question. You know, among my colleagues, we always say that's that, you know, sort of $65 million question. And I'm not quite sure where that number comes; maybe the amount of money that we need to actually figure this out.

But here's some information that we're starting to glean. A couple of months ago, Richard Seager from Columbia University and his colleagues published in Science, a peer-reviewed publication, a very interesting study that indicated that what we might be seeing here in the Southwest and in the West in general is an expansion of what we call the Hadley Cell circulation.

So as the entire climate system warms, the movement of the jet stream that brings, you know, moisture to us here in the West from the Pacific Ocean has started to migrate north. And arguably it's sort of going to sort of continue to move north and create a permanent dust bowl-type situation here in the Southwest.

Those are sobering thoughts. These are results that will continue to be examined and tested with data and with models, but it could mean that we're seeing a very fundamental shift here in western climate.

JEFFREY BROWN: And is this connected to all the concern and talk about global warming? Or is this a different kind of climate variability that you're looking at?

LISA GRAUMLICH: It's potentially related to global warming, but recall that I'm somebody that studies the past. And we know that very long and severe and pervasive droughts have occurred in the past. For instance, we know from tree-ring records that, in the mid-1100s, in sort of medieval times, we had a drought in the Colorado Basin that lasted six decades.

So we know that the climate system can move into these very dry states, and there's every reason to believe that this kind of drought may persist. I think sometimes we kind of have a coin-tossing mentality towards drought, that surely if it was dry this year, it will be wet next year. And that's not the way the climate system works. It tends to lock into these patterns and to lock in for a decade or more at a time.

Impact on people's lives

Lisa Graumlich
University of Arizona
[T]he fires that you were talking about now are almost becoming a way of life for us.

JEFFREY BROWN: So tell us, there you are in Arizona, what kind of impact does this have on people's lives or on what local governments are doing? We hear a lot about population explosion there, the demands on water. How does all this play out, given the drought?

LISA GRAUMLICH: Well, it plays out in a couple of ways. First of all, we in Arizona are acutely aware of this drought and have been for several years. For example, the fires that you were talking about now are almost becoming a way of life for us. In the last five years, almost 20 percent of the forested land in Arizona has burned. We're also seeing massive mortality of the pinion pine, the sort of beautiful pine forest that cover much of the northern part of New Mexico and Arizona.

So we are sort of feeling the drought and feeling the drought impacts. It has huge implications for those of us that live in the cities of the West, because we can exist in these cities largely because of the water from the Colorado River that is piped into Phoenix, Las Vegas, Los Angeles. And we know that, as populations are increasing in this rapidly growing part of the country, we're starting to potentially run into some limits. We in Arizona are particularly sensitive to that.

In the legal terms, we have junior water rights compared to California. So if the drought deepens and if Colorado River water needs to be divided, we're going to find ourselves in a pretty sticky situation, in terms of negotiating our way into some sort of sustainable system here.

JEFFREY BROWN: All right, Lisa Graumlich of the University of Arizona, thank you very much.