WILDFIRE + THE ENVIRONMENT
Burnout operations are conducted on the western flank of the Wallow Fire in northeastern Arizona in June. Extreme drought conditions in parts of the Southwest contributed to some of the largest wildfires ever recorded in the region, including the Wallow Fire, which burned more than a half-million acres. (Photo: Rick DiElia/Corbis)
Hot + Hotter
Global warning. Intense periods of drought. Stressed vegetation + trees. Forest-killing insects. Surplus fuel supplies. Experts says the current environmental conditions are in part responsible for some of the largest wildfires we've every seen. And things are just heating up.
NFPA Journal®, October 2011
By Alan Earls
Last spring, Arizona was one of the first states to feel the sting of the 2011 wildland fire season. The season began in early May with a 10,000-acre (4,047-hectare) wildfire in the Coronado National Forest, about 70 miles (113 kilometers) northeast of Tucson. Soon, more than a dozen conflagrations had flared up across the state, burning some 865,000 acres (350,053 hectares). The biggest was the so-called Wallow Fire, which began in the Bear Wallow Wilderness, about 100 miles (161 kilometers) northeast of the Coronado National Forest. The Wallow Fire ended up burning 538,240 acres (217,818 hectares), or 841 square miles (2,178 square kilometers) in Arizona and New Mexico, and has earned the distinction of being the largest wildland fire in Arizona history, with total damage exceeding $100 million.
"We started the season with drought conditions and winds, which combined to heighten the possibility of ignition," says Cam Hunter, Arizona’s deputy state forester. The drought and wind, combined with ample fuel sources, not only made ignition more likely, but also helped turn small fires into major events within a matter of hours. "We saw fires traveling seven miles in an afternoon and 13 miles the next day, reaching communities we never thought would be affected," says Hunter.
Arizona’s experience illustrates how the key environmental factors in wildfire — temperature change and wet/dry cycles of precipitation, combined with fuel sources, topography, and the ever-critical variable of wind — can align to create fires that are bigger, and cause more damage, than any seen before. Research using a variety of future climate scenarios predicts that the amount of biomass, including forests, scrub, grass, and brush, consumed by wildfire will at least double in the western United States over this century. According to studies by the National Center for Atmospheric Research, the western fire season now stretches to 205 days, 78 days longer than it was in the mid-1980s.
But the problem won’t just affect western states like California that are typically associated with wildfires. The United States Global Change Research Program predicts that the effects of climate change will impact areas where fire has traditionally not been as serious a threat, such as the Northeast and Upper Midwest. The 2011 wildfire season has included significant events from Minnesota to Texas, Florida to California, with at least three states — Texas, New Mexico, and Arizona — experiencing their largest wildfires on record. By mid-September, with a good portion of the fire season still ahead of us, nearly 58,000 fires had burned 7.5 million acres (3 million hectares) nationwide, according to the National Interagency Fire Center; the annual average for the previous 10 years was 6.2 million acres (2.5 million hectares).
Through its Wildland Fire Operations Division, NFPA is playing an important role in education, research, and policy formation related to the environmental factors of wildfire, with much of its work focusing on mitigation. NFPA began a wildland-urban interface (WUI) fire program in 1986, which evolved into the Firewise® Communities Program. As a key NFPA wildfire program, Firewise encourages local mitigation solutions for wildfire safety by involving homeowners, community leaders, planners, developers, firefighters, and others to protect people and property from wildfire risks. "Firewise is just one way we’re attacking the problem," says David Nuss, manager of the Wildland Fire Operations Division. "All you have to do is look at a newspaper on any given day to see how serious the wildfire problem is, not just here but around the world. NFPA long ago established itself as an international leader in fire and life safety, and that’s the kind of organizational background we bring to attacking the wildland fire problem."
Some of the wildland fire projection models try to take into account the effects of fire suppression and other human activities — those that reduce fire risks in the short and long term, as well as those that can exacerbate the likelihood of fire ignitions. Dwarfing that human activity, though, are the global patterns that cannot be changed, such as warming and cooling, El Niño and La Niña years, and wet and dry cycles. Based on climate data alone, the evidence for a future with more and possibly larger — and more damaging — wildfires can be overwhelming.
Climate change isn’t the only factor at work here, but it’s an important one. The World Meteorological Association reports that the period 2001 – 2010 is the warmest decade ever recorded. Average summer temperatures continue to rise globally, and seasonal drought patterns are persisting longer into the fall. Research (see "Mapping the future of wildfire" sidebar ) suggests that the Earth’s average surface temperature will rise by about 3°F (1.6°C) by 2050. In some places, the warming trend may be happening even faster. According to the Rocky Mountain Climate Organization, the 11 western U.S. states warmed an average of 1.7°F (0.9°C) between 2003 and 2007. Overall, gradually rising temperatures will prolong dry periods and intensify drought, leading to drier, more fire-conducive conditions across more of the Earth’s surface while creating additional fuel, mostly in the form of dry biomass. Some scenarios being studied suggest that in this warmer world, even wet periods will contribute to the overall wildfire losses by allowing more buildup of vegetation, resulting in more fuel for future fires when that vegetation dries.
Other climate phenomena play important roles, too. Research suggests that factors such as El Niño and La Niña — climatic conditions characterized by warming or cooling, respectively, of ocean temperatures in the Equatorial Pacific that can impact global weather patterns — can also affect fire weather around the world because of the disruption to rainfall patterns. The active start of the 2011 wildfire season in the U.S. proved to be no exception. Researchers in Florida have been tracking the state’s wildfire activity for the past 17 years and have found that the five most active years (by number of fires and acres burned) featured La Niña conditions immediately prior to or during the period when the state’s wildfire activity is at its peak. Meanwhile, Indonesia sees a sharp increase in wildfires during El Niño periods.
Like wildfire itself, factors like drought and El Niño are part of the planet’s natural systems and cannot be attributed to some catch-all catalyst like "climate change." The record fires that occurred in Texas, New Mexico, and Arizona this year also corresponded with record drought conditions, but it’s impossible to say what role, if any, climate change played in the severity of this particular drought. Other wildcard factors, like beetle infestations that have affected millions of acres of forestlands in the West, can play important roles in determining how fire-prone an area becomes.
"People look at the drought and fire conditions we’ve had in recent years and see a direct connection to global warming, but in fact the drought conditions are actually not out of the norm for the recent historical past," says Stephen J. Pyne, a fire historian and professor at Arizona State University. Pyne also points out that prolonged drought can actually reduce the amount of some fuel sources, such as grasses. Over the long term, though, he says, global warming will tend to exacerbate underlying wet/dry patterns around the world.
Pyne, like most wildfire experts, favors a big-picture view of the wildland fire problem, keeping climatic factors closely linked to settlement patterns and our past efforts to manage or suppress wildland fire — which in many instances have resulted in a long-term accumulation of burnable fuel, which can result in bigger and more destructive fires. Efforts to restore fire to its place in the environment through planned burns or through less aggressive approaches to suppression have been halting and less than successful, he says. "It’s more than a technical problem," Pyne says. "We don’t know how to do it because we can’t agree on what the land is to become, so the problem is being handed over to wherever fire starts."
NFPA, WUI, and mitigation
In many parts of the country, though, the environmental factor of fuel load must be managed carefully and consistently, as it is on the Cape Cod National Seashore, with its potentially volatile mix of pitch pine, scrub, and grasses.
David W. Crary, Jr., is the National Park Service Fire Management Officer for the seashore, and oversees 45,000 acres (18,211 hectares) of forested landscape. That land historically burned once every 30 years prior to European settlement, Crary says, and in more recent times fire was a frequent threat when cinders from steam-powered locomotives found plenty of ready tinder.
Today, with a growing population within and around the seashore area, fire suppression is a top priority. To ensure fires stay manageable, Crary oversees an active prescriptive burning program to keep fuel sources from becoming too extensive and to try to achieve a better mix of plants that are better able to resist and recover from fire. He also manages a set of plots used to test different prescriptive burning techniques. "Through trial and error we believe we’ve found the best ways to burn to control the plant species we have here," he says.
Cape Cod illustrates one of the most complex, and expensive, elements of the wildfire problem, which is the introduction of human settlement into fire prone environments — otherwise known as the wildland-urban interface, or WUI. Wildfire doesn’t distinguish between a tree, a bush, a house, or a car: fuel is fuel. In the WUI, though, the assumption among property owners is too often that federal agencies, like the U.S. Forest Service, or local fire departments will be available to fight those fires and protect property. Sometimes those resources are available, but often they aren’t. Regardless, firefighting in the WUI accounts for the lion’s share of the more than $2.5 billion, on average, spent annually on suppression efforts by federal agencies.
Pyne says that, considering how and where fires start, what they burn, and how they’re suppressed, many wildfires are "really just urban fires in an unusual setting." WUI fires make up most of the costliest wildfires ever and account for three of the 15 most expensive fires of any kind. Topping the list of most expensive wildfires (and fourth costliest of any kind) is the Oakland Fire Storm, which took place October 20–21, 1991, in Oakland Hills, California. The fire destroyed 3,300 homes, killed 25 people, and caused damage estimated at $2.4 billion in 2008 dollars, according to NFPA data.
To avoid such calamities in the future, NFPA is promoting a variety of mitigation strategies, such as those included in its successful Firewise©, program, and is also working closely with the International Association of Fire Chiefs and its Ready, Set, Go! program, a complement to Firewise. Earlier this year, NFPA announced a formal relationship with Partners in Protection (PiP), a Canadian non-profit association focused on reducing wildland fire loss. NFPA will support PiP in its efforts to further develop its FireSmart recognition program, which is similar in scope to the Firewise Communities/USA© program in the U.S.
NFPA has also helped to establish accepted standards for evacuation procedures in at-risk areas and to improve the collection of statistical information on wildland fires. "I think one of our most important roles is to be a provider of research information down to the community level," says Nuss.
Last year, Nuss created an advisory committee to help define NFPA’s role over the next three years. The committee helped formulate a plan to strengthen Firewise as NFPA’s leading public outreach program and assisted in the launch of a study that is looking at the effectiveness of regulations related to wildland fire protection. The study, slated for completion in December, will catalog existing regulations, assess their effectiveness, and identify potential barriers to improving the effectiveness of regulations.
"With those findings, we’ll determine the next steps to take in terms of the regulatory environment and what would be a good role for NFPA to play," Nuss says. Those steps include possible partnerships with planning organizations if the study indicates a need for better land use regulation.
"This is the best way we can address some of these very large environmental issues," Nuss says. "We can’t control El Niño, and we can’t control winds from a tropical storm that push wildfires into places they’ve never been before. But we can educate people so they can minimize the impact of those fires, and we can collaborate with organizations that can help us further spread our messages. And as a leader in all aspects of fire safety, people will listen to what NFPA has to say."
Alan Earls writes on technical and safety topics and is based in Franklin, Massachusetts.
Mapping the future of wildfire
As part of their research on future wildfires and the impact of those fires on the air we breathe, a group of atmospheric scientists led by researchers at Harvard University predict that large parts of the western United States could see dramatic increases in the area burned by wildfire over the next several decades. The map above shows the predicted percentage increases in area burned between now and approximately 2055.
In a study published in 2009 in the Journal of Geophysical Research, the scientists predict that the overall geographic area typically burned by wildfires in the western U.S. could increase by about 50 percent between now and the 2050s due mainly to rising temperatures, with some areas experiencing much higher rates. The greatest increases in area burned, ranging from roughly 75 percent to 180 percent, would occur in the forests of the Pacific Northwest and the Rocky Mountains, indicated on the map in orange and red, respectively. (While the large gray area in the center of the region includes pockets that may see a decline in wildfire area burned, the researchers say most of that area will experience at least a nominal increase in the area burned.)
The team examined a 25-year record of observed meteorology and fire statistics to identify factors that could predict area burned for each ecosystem in the western U.S. To see how these factors would change in the future, they ran a global climate model out to 2055. This scenario, one of several devised by the Intergovernmental Panel on Climate Change, describes a world with rapid economic growth and balanced energy generation from fossil and alternative fuels, which leads to a moderate warming of the earth’s average surface temperature, by about 3o F (1.6o C), by 2050.
How a beetle infestation poses a major wildfire threat to western forests
Throughout much of the North American West, a bark beetle epidemic is damaging forests and making them ripe for wildfire. Beetle infestation has devastated nearly 4 million acres (1.6 million hectares) of lodgepole, white, and ponderosa pine forests in British Columbia, Washington, Oregon, California, Utah, Colorado, Idaho, Montana, and Wyoming. The long-standing practice of wildland fire suppression, which prevented the bugs from being killed off in fires while providing them with more older and weakened trees to attack, is just one factor in their unprecedented onslaught. Milder winters mean more bugs survive into the spring, and drought conditions provide yet more stressed trees for them to infest.
As Tom DeGomez, an entomologist with the University of Arizona Cooperative Extension Service, explains, the beetles aren’t always a problem. Healthy trees resist their efforts to bore holes and create living space and can, in fact, withstand mild infestations. However, when trees are under stress — and particularly in areas where large groups of weakened trees are roughly the same age — an initial infestation can lead the beetles to issue a pheromone signal that encourages other beetles to come and join the bonanza. And that can quickly lead to the deaths of large numbers of trees.
Fire professionals have found that these damaged trees quickly give up their remaining moisture, leaving a particularly dangerous fuel source of tinder-dry needles at the crown — a perfect medium for nearly instantaneous fire transmission across the top of the forest canopy.
Little can be done to fight the bugs. DeGomez says insecticides can slow them down and that false pheromone signals can somtimes ward them off. But the best defense, he says, is a more age- and species-varied forest, which is not only less enticing to the beetles but is also less prone to fire, even when some trees have been killed by the bugs.
Matt Jolly, an ecologist for the U.S. Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, says he isn’t particular about how beetles are discouraged. But having seen the results of beetle damage, he’s convinced that better management of woodlands — and, by extension, of the beetles — is an important component in reducing wildland fire risk. “The whole resiliency concept means the more variety you have across the landscape, the more likely you are to avoid a major infestation,” he says. And, he adds, the more likely we are to avoid major wildfires.
— Alan Earls