A day after NBC blamed the California wild fires on global warming, CBS on Wednesday night cited global warming, but also gave equal emphasis to how years of putting out fires has provided more fuel for them in the form of thick trees and brush. From Escondido, California, anchor Katie Couric asserted the wild fires are “more intense today than ever, and John Blackstone reports, man may be at least partly to blame for that.” Blackstone first went to global warming: “Fire ecologist Tom Swetnam has a collection of tree rings that reveals thousands of years of climate history. He told Scott Pelley of 60 Minutes that global warming means a longer fire season.”

Then, however, Blackstone considered another cause: “A whole lot more fuel to burn, a result of a hundred years of fighting fires” since “putting out almost every fire is not what nature intended, says Richard Minnich, who studies fire history.” Minnich, a professor of earth sciences at the University of California Riverside, explained: “The fire suppression management over the hundred years, in fact, generates more severe fires than what would otherwise occur.” Plus, Blackstone noted, the destructive impact of the fires has increased because “the realization it's often good to let fires burn has met a big obstacle: more houses in forest and wild lands.” Concluding his piece, Blackstone returned to warming, but didn't blame it alone: “Firefighters are trying to keep up with the megafire threat, a threat that won't go away in a warming world, and a growing West.”

The October 23 NewsBusters posting, “Without Proof, NBC Presumes Global Warming to Blame for Wild Fires,” recounted:

ABC and CBS stuck Tuesday night with news stories on the impact of the roaring California wild fires, but as houses were still burning NBC Nightly News found it an opportune time to make the case that global warming caused the fires. NBC's sole expert, however, delivered a circular argument in which the lack of scientific proof did not detract at all from his media-shared presumption that anything bad which occurs in the environment can be tied to global warming. After reporter Anne Thompson cautioned scientists say you can't know “after just one season” whether warming is to blame, Princeton professor Michael Oppenheimer, a leading global warming alarmist who, NBC failed to mention, serves as a science adviser to Environmental Defense, reasoned: “The weather we've seen this fall may or may not be due to the global warming trend, but it's certainly a clear picture of what the future is going to look like if we don't act quickly to cut emissions of the greenhouse gases.”

Standing in smoldering ruins of a home in San Diego County, anchor Brian Williams introduced the story: “This has been the driest season on record, unusually severe, that's leading some people here to wonder: Are these fires somehow a result of climate change? The UN panel on global warming did warn that we would see more wildfires, so is there a real connection? We've asked our chief environmental affairs correspondent, Anne Thompson. But Thompson is hardly in a position to provide an independent assessment. In August, she filed a story smearing critics of global warming panic as “deniers” and “denier groups”and, the day Al Gore won his Nobel Peace Prize, she endorsed his position on the threat of climate change.

With two uses of the “could” caveat, Thompson asserted in her Tuesday piece: “A new study out this week suggests the impact of climate change could be stronger and sooner than expected. And one of the predicted impacts from climate change could be more wildfires.” She soon added: “The wildfires are just one example of this fall's extreme weather: Tornadoes in Michigan, a lack off fall color in the Carolinas, the spectacular foliage muted by drought and warm temperatures....And here in Minnesota's twin cities, they are still awaiting the first official frost.”

The MRC's Brad Wilmouth corrected the closed-captioning against the video to provide this transcript of the October 24 CBS Evening News story:

KATIE COURIC: Back now from the command center where strategy is planned for fighting the biggest of the Southern California wildfires. Officials believe that fire, the Witch Fire, may have been caused by downed power lines. And as we reported earlier, at least one of the fires is believed to be arson. However wildfires start, they're more intense today than ever, and John Blackstone reports man may be at least partly to blame for that.

JOHN BLACKSTONE: With hundreds of thousands of acres burning in Southern California, these are fires on a scale once unknown. We are now in the age of the megafire, a threat that has been building for a century.

ASSEMBLYMAN TODD SPITZER, (R-CA) We always knew this day would come. This is the day of reckoning.

BLACKSTONE: That reckoning isn't only in California. It's throughout the West, where fires have been burning bigger, hotter, and faster.

DIRK KEMPTHORNE, SECRETARY OF THE INTERIOR: The nature of the fires is changing. In many of the areas, we're approaching 10 years of drought. So the trees are stressed.

BLACKSTONE: A problem that gets worse as the earth gets warmer. Fire ecologist Tom Swetnam has a collection of tree rings that reveals thousands of years of climate history. He told Scott Pelley of "60 Minutes" that global warming means a longer fire season.

THOMAS SWETNAM, FIRE ECOLOGIST: The fire season in the last 15 years or so has increased more than two months over the whole western U.S.

BLACKSTONE: Add to that, a whole lot more fuel to burn, a result of a hundred years of fighting fires.

RICHARD MINNICH, FIRE HISTORIAN: Ninety-nine percent of the fires are put out, but there's that one percent that gets away.

BLACKSTONE: But putting out almost every fire is not what nature intended, says Richard Minnich, who studies fire history.

MINNICH: The fire suppression management over the hundred years, in fact, generates more severe fires than what would otherwise occur.

BLACKSTONE: In 1988, Yellowstone National Park went up in a firestorm. Decades of putting out every fire had left the park unnaturally thick with trees and debris, the first megafire. But the realization it's often good to let fires burn has met a big obstacle: more houses in forest and wild lands.

KEMPTHORNE: The idea of just a massive, "let it burn," we don't do that.

BLACKSTONE: It leaves firefighters trying to protect homes surrounded by vegetation ready to explode. This air war is essential in neighborhoods like this where homes are backed right up against a rugged hillside. Firefighters are trying to keep up with the megafire threat, a threat that won't go away in a warming world, and a growing West. John Blackstone, CBS News, Orange County, California.

—Brent Baker is Vice President for Research and Publications at the Media Research Center