The higher temperatures drying the West had created such deadly conditions this winter that Colorado authorities were on alert, seven weeks before the Marshall firestorm, as multiple fast-moving grassfires broke out in Front Range cities.
They even had air tankers ready.
But wind-whipped flames accelerating through houses 15 miles northwest of Denver Dec. 30 rendered firefighters powerless.
And now in the aftermath of the state’s most costly climate-driven inferno, officials and experts contend “hardening” of high plains suburbs, similar to the flame-proofing proposed for mountain towns, may be necessary everywhere to endure future fires.
“We thought suburbia wasn’t as vulnerable,” University of Colorado fire scientist Jennifer Balch said. The Marshall fire showed “we are sitting ducks to the repercussions of the climate that we have to deal with year-round.”
“One problem is climate change, the warming. Another is that more homes are built in the line of fire,” Balch said, pointing to the thousands of new houses installed over 25 years between Denver and Boulder. “We need to re-think how we’re building in flammable places. And, we’ve been building homes that are flammable.”
For years in Colorado, climate warming has been leading to progressively drier, more flammable conditions and more winter grassfires — because hotter air leaches more water from land and rivers into a thirstier atmosphere. Temperatures in parts of western Colorado have been rising nearly twice as fast as the global average increase. And climate warming will intensify for at least two more decades, scientists say, even if world leaders succeed in drastically reducing consumption of fossil fuels.
This winter, Colorado officials had measured soil moisture along the Front Range at record low levels following a record hot summer and fall. And they recognized implications of the exceptional absence of snow: dead grass that normally would be buried or matted stood upright, able to function as a superconductor for flames. All it would take is ignition, which happens regularly now with Colorado’s population approaching 6 million.
Seldom had the trend toward more winter grassfires inside cities been more evident than during the seven weeks before this disaster: A Nov. 14 outbreak in western Colorado Springs forced evacuation of 22 homes. Four more grassfires broke out on Dec. 12 in Colorado Springs along Interstate 25. A grassfire Dec. 23 in Boulder burned six acres along a creek path. A 150-acre grassfire Dec. 27 near C-470 in southwest metro Denver forced thousands of residents to flee. Severe wind, common as winter storms roll across the Rocky Mountains to the plains, caused havoc Dec. 15, toppling trucks and trees. And wind exacerbated a 145-acre forest fire Nov. 16 west of Boulder near Estes Park.
“We were paying attention to all these things as they were happening,” state climatologist Russ Schumacher said in a Denver Post interview. “It had been so dry, going back to the start of summer, and so warm here along the Front Range. And we’d seen the smaller fires pop up,” Schumacher said.
“Our awareness was up. But I don’t think any of us imagined what we saw last week was going to happen – such a fast-moving fire burning through neighborhoods. You look back and with hindsight you see all the ingredients were there. But it’s still hard to get your mind around the idea that this is going to happen.”
In the destruction that day, wind gusts as high as 105 mph grounded the state’s firefighting air tankers. Flames burning dried grass began kicking up embers, the way forest fires do, igniting houses. And buildings themselves became a main source of fuel that accelerated the fire through home after home, destroying 1,084 structures and damaging 149 more across 6,026 acres before snow finally fell and snuffed flames.
Natural forces unleashed by an out-of-kilter climate essentially overwhelmed firefighters, preventing them from attacking flames. All they could do was – heroically – hasten the evacuation of residents to save lives, said Mike Morgan, director of the Colorado Division of Fire Prevention and Control.
“What do you do when you have hurricane-force winds with fire?”
Morgan has helped lead Colorado’s ramping up of “rapid response” capabilities to suppress forest fires before they blow up, including acquisition of a $24 million Fire Hawk helicopter as part of this year’s overall $78 million push. But firefighting aircraft typically aren’t deployed in wind over 50 mph.
As Colorado temperatures rise for at least 20 more years “under the best-case scenarios,” Morgan said, “we will see more and more of these types of events” where “the traditional methods are not effective” to stop flames.
“It has taken us a while to get into this predicament. It’s going to take us a while to get out of it,” Morgan said. “We will hear a lot more conversations about ‘mitigation’ through vegetation management. We’ll hear discussions about fire suppression. It looks like we’re going to hear conversations about building code standards. But are we really looking at this from every possible angle we can? What are we doing about hardening communities? Are people serious about protecting themselves? Are we having serious conversations about land use?”
The Marshall disaster has driven scientists, climatologists and public safety officials back to the drawing board in their understanding of how climate warming can hit home. Here’s their emerging list of lessons learned:
- The drying-out of Colorado landscapes happens progressively faster the more temperatures increase. A thirstier atmosphere can convert grasslands well-watered in spring to desert-like aridity within months.
- Potentially ruinous fires can threaten communities anywhere and anytime.
- The difficulty of combatting big wind-whipped fires under dry conditions means first responders increasingly can only guide evacuations. Front Range residents must know their own escape routes and be resilient.
- Climate calamities often compound with cascading impacts, such as the mudslides off burned slopes following forest fires that closed Interstate 70 in western Colorado last year. This time, flames found a major new source of fuel in dense-packed housing that supercharged destruction.
- Fires now threaten much wider areas than previously understood. Colorado public safety officials for a decade have prepared for fire in carefully mapped “wildland urban interface” zones designated as “high-risk” after developers install houses and shops next to forests — where roughly half the state’s residents reside. The Marshal firestorm raged through domesticated areas widely presumed to be safe.
- Building more housing along the Front Range raises risks of catastrophes.
“We really have had to re-think some of the things that are possible with wildfires here in Colorado,” Schumacher said. “As there’s increased development, you have structures to burn that weren’t there a few decades ago — a whole new side of this.”
Federal authorities also are re-thinking strategies for dealing with fires in the aftermath of the Marshall disaster, which prompted a visit Friday by President Joe Biden.
“The pace of wildfires during the past two years has been eye-opening to us,” said Nick Nauslar, predictive services meteorologist at the National Interagency Fire Center in Boise, where firefighters scramble to suppress flames that since 2015 have burned as much as 10 million acres a year.
Forecasting future potential fire disasters in the West has proved more difficult than tracking the hurricanes that repeatedly hammer Gulf Coast states. A major challenge is wind, especially along the Rocky Mountain front from Montana to New Mexico.
Federal scientists have begun research on whether climate warming may cause an overall increase in wind — inconclusive so far. It’s complicated because many extreme wind events depend largely on local topography, said Julie Lundquist, a CU atmospheric scientist working with wind experts at the National Renewable Energy Lab.
“Even if climate change only increases the prevalence of dry conditions, without increasing wind conditions, the risk of fire scenarios like last week would still increase,” Lundquist said.
In the past, gusts west of Boulder reached 137 mph (January 1982), said Gerald Meehl, a senior scientist at the National Center for Atmospheric Research who is conducting a study on climate warming and wind. At 100 mph west of Boulder, wind “can combine with fire to cause havoc and extensive damage,” Meehl said.
This time, a National Weather Service team in Boulder had issued a high wind warning six hours before the Marshall fire ignited.
Yet still, it led to disaster — the latest in a pattern where increasing temperatures coincide with frequent shattering of old norms.
Back in 2012, the post-Thanksgiving Fern Lake wildfire in Rocky Mountain National Park raced three miles in 35 minutes across eight inches of snow to within half a mile of Estes Park. “We thought that was an anomaly,” Morgan this week recalled.
But by 2020 the biggest forest fires in state history (Cameron Peak at 208,663 acres, and East Troublesome at 192,560 acres) burned in October. And last year on Super Bowl Sunday Feb. 7, two grassfires broke out inside metro Denver, forcing evacuations of thousands of homes.
The fires near people are raising fears and frustrations. Climate activists are pressing Gov. Jared Polis to declare an official “climate emergency.” They gathered more than 200 signatures and plan a “State of the Climate” rally Jan. 13 before the governor’s “State of the State” presentation.
Meanwhile the Colorado Fire Commission, tasked by Polis with brainstorming strategies for addressing the fire problem, has been meeting four times a year since October 2019. The 24 voting members of the commission — public safety chiefs, firefighters, sheriffs, an insurance industry representative, stewards of natural resources — have been discussing possible new measures including stricter building codes that require use of non-flammable materials in new home construction, limits on construction in fire-prone areas, and increased use of prescribed fire to try to restore species diversity and spacing in the state’s dying forests.
They haven’t reached a consensus but are expected submit recommendations this month to lawmakers.
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