IN 2002, WILDFIRES raged in many parts of the West and pressed the nation's firefighting capacity to its limit. In Colorado's Front Range, the huge Hayman fire filled the sky with smoke for days and showed that wildfire could encroach on the edges of a major city, Denver.
It was a first-rate wake-up call to the dangers these fires create -- and we woke up. Most important, we began to take responsibility.
No longer could communities in the West legitimately claim ignorance of their vulnerability to fire. We came to understand that the widespread building of homes and resorts in forests escalated the financial consequences of fire in wild lands. Defending these structures from flames added a moral dimension to the issue: The lives of young firefighters and smokejumpers were increasingly at risk protecting property.
The new responsibility had many forms. Homeowners cleared trees and brush around their houses. Local governments adopted tougher rules on development in high fire-risk zones. Insurance companies revised their policies to reward owners who exercised foresight and took action to prevent fire.
But a recent scientific study could easily be misinterpreted as an invitation to go back to sleep. It is also an indicator of how politicized some environmental science has become and the problem that poses for taking responsibility in a region prone to fire.
The authors of "Warming and Early Spring Increases Western U.S. Forest Wildlife Activity," published this month in the journal Science, reach a thought-provoking conclusion: Climate change has been the "primary driver" of the increase in big wildfires in the West, even more than recent changes in land use or the unnecessary suppression of natural fires. Warmer temperatures have melted the snowpack earlier in the spring, producing a longer dry season and more combustible materials. Thus the opportunities for big fires to start have multiplied.
Should we now blame a changing climate for the West's wildfire problem? Or should we continue to change land use and management practices to reduce the fire danger? And how should our answer shape our conduct?
After Colorado's 2002 fire season, representatives from environmental groups, federal and state agencies, utilities, insurance companies, universities and county governments convened in the state to find a solution to a problem caused by decades of fire suppression. It was a very mixed group, and I imagine many of them would cancel each other out at the polls. The group's name was a bureaucratic mouthful: the Front Range Fuels Treatment Partnership Roundtable.
The key word in this undertaking was responsibility, and in the judgment of many who participated, myself included, we accomplished something. The "fuel" in forests along the Front Range had reached worrisome levels. In the absence of fire, the density of flammable trees and underbrush had greatly increased. We surmounted mutual distrust and reached a consensus for which fuel areas to target and which strategies would best reduce the danger of future fires.
But now, if we declare climate change the primary driver of increases in wildfires, as the study in Science suggests, what could a plucky group of Coloradans possibly do to find a remedy for this problem?
Of course, if climate change explains the greater frequency and intensity of the West's wildfires, the question of responsibility shifts levels, and we are immersed in one of the most contentious issues of science and public policy. Is human behavior -- the use of fossil fuels as the main energy source -- warming the planet, or is the rise in temperature part of a natural cycle that has occurred in Earth's past?
The study's authors skirt this question. "Whether the changes observed in Western hydro-climate and wildfire are the result of greenhouse gas-induced global warming or only a usual natural fluctuation is presently unclear," they write.
But is it possible for a group of scientists in 2006 to study an issue -- wildfire -- immersed in contention, put forward an explanation based on climate change and then sidestep the question of whether humans bear any responsibility for that climate change?
The question of human culpability is a big roadblock to resolving many environmental dilemmas. Thanks to it, the findings of environmental scientists are often the spark for contention and misinterpretation rather than understanding and discussion. It's not easy to think of a scientific study on the natural world that doesn't have some connection to contested public policy. Biologists who simply want to study wildlife may find themselves enmeshed in political battles over the status of threatened or endangered species. Geologists and hydrologists may be drawn into disputes over the safety and permanence of waste disposal sites.
In such circumstances, these scientists have reason to feel like zookeepers feeding hungry animals: Their study findings barely hit the ground before advocates and rivals pounce on them, snarl and tug at each other over them, then tear the whole into pieces to secure the choicest parts.
This rowdiness is called "data dispute," and it's becoming a popular sport in environmental circles in the West. It doesn't show us at our best. Nor does it make the most of the enormous resources of the natural scientists studying the West's environment.
So let's not dispute data this time.
In too many environmental disputes, we squabble over the management of materials -- sewage, spent nuclear fuel, carbon emissions, outdated computer parts. Meanwhile, the question of who will take custody of that unpopular substance called responsibility remains the most contentious and consequential matter of all.
The current condition of the West's forests has multiple causes. Climate, fire suppression, government regulation (or its absence) and the construction of buildings in forested areas all play a part in creating it. Regardless of which factor we accent in our explanations, we still have a big problem before us. And we still must take responsibility for it and find a remedy. The findings of climate scientists do not diminish that responsibility. The wake-up call of 2002 still summons us to action.