LIANE HANSEN, host:
Three years ago, journalist Rocky Barker published "Scorched Earth: How the Fires of Yellowstone Changed America." Barker argues the million-plus acres that burned across Yellowstone in 1988 radically shifted fire policy and indicated long-term change was afoot.
Mr. ROCKY BARKER (Journalist): We can look back and see that, actually, these fires were the signal fires. They were the signal fires of the climate change that we are all living with today.
HANSEN: The connection between climate change and fire is something that experts and scientist are still trying to figure out. Sadie Babits of Boise State Public Radio reports.
SADIE BABITS: 1988 was an incredibly hot and dry year, not just in Yellowstone, but across the country. Air conditioners flew off the shelves as record heat hounded major cities. There were dust storms in the Midwest, and fires like no one had never seen before raged through Yellowstone National Park.
Mr. RICK OCHOA (Fire Program Manager, National Interagency Fire Center): We thought this was going to be the culmination, there is never going to be another fire season like this. Because, at least for me, this was the biggest fire season I'd ever seen.
BABITS: That's Rick Ochoa. He calls himself a fire weather detective. 20 years ago, he was at Yellowstone forecasting weather to help fire crews understand what the blazes might do. Now, he is the fire program manager at the National Interagency Fire Center in Boise, Idaho, the nerve center for coordinating firefighting activity across the country.
Mr. OCHOA: Every day is kind of like a little puzzle. You've got to find out, OK, are we going to get lightning? And if we get lightning, is there going to be rain with it? How much rain? How fast the storm is moving? Because all that plays into the potential to getting a large wildfire.
BABITS: The fires of 1988, he explains, were the result of a climate that had been warming steadily through the 1960s and 70s. Those dry, warm conditions have continued ever since.
Mr. OCHOA: You can see the dryness here in this red and orange area.
BABITS: Ochoa's eyes scan a large computer screen as he points out weather patterns across the U.S. He didn't have this high-tech gear when he was forecasting the Yellowstone wildfires. Ochoa says predicting fire behavior now and into the future is critical.
Mr. OCHOA: We know there's going to be a more dangerous situation out there. So that we know that our forecasts have to get better so that we can time those wind changes, we can time when the lightning is going to occur, and we have to be just be more proactive.
BABITS: Large stand-replacing fires, the fires that wipe out entire forests, have been on the increase for the past 20 years. Wildfires are also burning longer, costing millions of dollars to fight. And fire season now lasts year round. Starting in January in Florida, gradually migrating later in the year to the west. What all this means for the future of forests is something Jen Pierce, a geosciences professor at Boise State University, wants to understand.
Dr. JEN PIERCE (Department of Geosciences, Boise State University): Oh, that's a great one. Wow! Sweet!
BABITS: She pushes past downed tree limbs toward a giant ponderosa pine scarred by past fires.
Dr. PIERCE: During a fire, when the bark of the tree gets damaged, that preserves a record of that fire as a scar on the tree. And since the tree has annual growth rings, you can tell the date that that scarring occurred and therefore, the date that the fire occurred.
BABITS: It's one method Pierce uses to reconstruct fire history. In addition to fire scars, tree ring data and charcoal found deep in the soil can help create a historic snapshot of climate and fire.
(Soundbite of digging)
BABITS: Here (unintelligible) with a small shovel. Other researchers from the Southwest to the Pacific Northwest are doing similar work. Their combined data can give a better understanding of what regional climates were doing thousands of years ago.
Dr. PIERCE: The mid-1980s was really when we started to see this recent increase in these large stand replacing fires. But that has happened during other warm-dry periods in the past. For example, about a thousand years ago was a time characterized by multi-decadal droughts in the west.
BABITS: Pierce says they now know that fire went hand-in-hand with those droughts, just like today. Climate, she explains, remains the major control for wild fires. For NPR News, I'm Sadie Babits in Boise.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.