JUDY WOODRUFF: But first: Wildfires are burning across a big section of the country and have
been for weeks.
Fires are a problem, as we know, most summers, but the severity and the scope of what is
happening in the Western and Southwestern U.S. this year is posing big problems for
officials, for residents, and for firefighters on the line.
And as Miles O'Brien reports, climate change may be magnifying the problem in California
and elsewhere.
MILES O'BRIEN: Facing high winds and triple-digit temperatures, firefighters are battling rapidly
expanding wildfires across California.
In some places, mass evacuations are under way as authorities race against the clock
to save lives and property.
At a local TV station in northern California, the anchors became part of the story.
ALLISON WOODS, KRCR-TV: We have been here live, and, right now, we are being evacuated.
That's why we are kind of closing out right now.
We are going to leave the station because it is now unsafe to be here.
MILES O'BRIEN: One big blaze, known as the Carr Fire, crossed over the Sacramento river
into Redding, a city of 91,000 residents.
Two firefighters were killed, at least 65 homes destroyed.
Chris Anthony is a division chief with Cal Fire.
CHRIS ANTHONY, Cal Fire Division Chief: You see these large and very damaging fires that
travel extremely fast and have huge impacts on communities throughout the state.
The trends are clear that fires are increasing in size and severity, as well as with the
destructive nature of the fires as well.
MILES O'BRIEN: Mandatory evacuations expanded as high temperatures and dry conditions made
it easier for wildfires to spread across the central and southern sections of the state.
Poor air quality and visibility have limited the ability of helicopters to help fight the
flames in valleys and low-lying areas.
Earlier this week, the giant Ferguson Fire cast a thick pall of smoke over Yosemite National
Park, forcing park officials to close the gates.
MICHAEL REYNOLDS, Superintendent, Yosemite National Park: This is a full suppression
fire, and we are fully engaged.
We have even authorized dozer line inside Yosemite, which is hardly ever done.
MILES O'BRIEN: It was the first time the park had been shut down since 1990.
MICHAEL REYNOLDS: Get yourself out of here if you can.
MILES O'BRIEN: Thirty-four hundred firefighters are on the Ferguson fire lines just two miles
outside the park.
KATHRIN POETTER, Tenaya Hotel: We're very, very dependent on tourism, just like the rest
of the community.
And this is our peak season.
MILES O'BRIEN: And in Southern California, the relentless Cranston Fire, which started
on Wednesday, also exploded overnight.
It has forced thousands to flee mountain towns 100 miles east of Los Angeles.
SUZANNA CROFFER, Evacuee: When we left, it was last minute yesterday afternoon, around
1:30 that we finally left.
And my husband was taking pictures of the planes coming forward.
And he said it's time to go.
MILES O'BRIEN: With five large fires burning right now, California has gotten much of the
national attention, but the picture nationwide is not good either.
There are 89 large fires burning more than 870,000 acres across 13 states, mostly in
the American West.
Oregon and Alaska are each dealing with 15 fires.
Larry Sutton is with the U.S. Forest Service, part of the national interagency fire center.
LARRY SUTTON, U.S. Forest Service: Our national preparedness level, which is an indicator
of the level of fire activity and resource commitment, is at its highest level now, which
is preparedness level 5.
So, we have got multiple geographic areas in the country that are heavily engaged in
firefighting right at the moment.
MILES O'BRIEN: Tell me about the resource challenge.
LARRY SUTTON: Well, so usually, for us, when we have a lot of fires all over the country
and all over the landscape, it's -- the exercise is a little bit like spreading not enough
peanut butter on too much bread
We have a lot of resources to commit, but once we have a certain level of activity,
it becomes all about prioritization of resource allocation.
MILES O'BRIEN: Scientists say there are many factors at play here, including human encroachment
deep into forests that are prone to burn naturally, and years of aggressive fire suppression that
has greatly increased the available fuel.
Researchers say climate change is also part of the picture.
Hotter and drier conditions make fires more likely.
They say all of this is a perfect storm that leads to much bigger fires that are much harder
to contain.
Park Williams studies climate and ecology at the Lamont-Doherty Earth Observatory of
Columbia university.
PARK WILLIAMS, Lamont-Doherty Earth Observatory: The place where we really see a strong link
between climate change and increased fire is in forests.
And the reason for that is because, in forest, there's plenty to burn.
So all you need to do is dry that -- dry that stuff out and it will burn more.
What we have seen, especially in forested areas, is that, as we turn up the temperature
even by one or two degrees, then fire responds in a pretty -- in a large and measurable way
because the vegetation dries out.
MILES O'BRIEN: And it's not just the United States.
Fires are raging even above the Arctic Circle in Sweden.
And earlier this week in Greece, a fast-moving wildfire killed more than 80, injured dozens
and destroyed more than 500 homes.
Fire officials everywhere say it is time for us to learn how best to live with fire, as
scenes like this are the new normal.
I'm Miles O'Brien for the "PBS NewsHour."