North America is witnessing the largest pine-beetle epidemic in recorded history. Temperature rises are more than likely to blame, but why is it so hard to admit that?
DILLON, Colo.--Dan Gibbs keeps dead beetles in the back of his beat-up Chevy Silverado. He has a wooden block with beetles impaled on it, each insect about the size of a grain of rice. He's got vials of embalmed beetles and their larvae. He carries around pieces of wood that show what those tiny beetles do to a mature lodgepole pine: They drill deep into the trunk and infect the tree with a fatal fungus that stains its wood blue.
Gibbs isn't a scientist. He's a commissioner for Summit County, a high-altitude slice of Colorado that's gaining fame as a ground zero, of sorts, for an epidemic that has devastated pine forests across North America. Twenty years ago, the mountainsides around Dillon were a lush green; these days, they're gray with needle-less trees.
The pine-beetle epidemic provides perhaps the most visual evidence of climate change in the United States. But that evidence, while arresting, remains circumstantial. Scientific studies linking the factors that drove the epidemic to rising global temperatures haven't convinced everyone, let alone prompted people here to forsake fossil fuels.
It isn't just the dead trees. Here, near the headwaters of the Colorado River, the snow is melting earlier--and there's less of it. Summers are drier. Threats of wildfire and water shortages have grown, changing lives and livelihoods in Colorado and across the West.
- Obama vs. Romney on Regulation
- U.S. Will Stop Deporting Young Illegal Immigrants
- Bridging Today's Generation Gap
Still, it's not simple to draw a bright line from observable phenomena to climate change. For some policymakers, the lack of clarity is frustrating. Mounting evidence that the planet is warming and that human activity is to blame hasn't generated any sort of political momentum for action, even as, in places like Dillon, forests are dying in plain sight.
As people here struggle to understand the beetle epidemic, the term "climate change" has become so inflammatory that few even utter it. It's also unclear to residents what, exactly, they would accomplish by reducing their fossil-fuel use. Without a more far-ranging plan of attack on a national--indeed, international--scale, all that people in Dillon and places like it can do is adapt to changing circumstances.
Gibbs keeps beetles in the back of his pickup to teach people about forest health, not to start a conversation about climate change. (And he, like almost everyone in the mountains, drives a gas-guzzling truck.) "Does climate change play a role in it? For sure, I think," Gibbs said of the pine-beetle epidemic. But, he added, "I think scientists are still really studying it."
DEEP IN THE FOREST
John Mack has a saying: "These trees are dead; they just don't know it." Along a back road to a campsite in Rocky Mountain National Park, the chief of resource stewardship at the park points out seemingly healthy trees covered in ugly, popcorn-shaped masses, a lodgepole pine's natural response to the mountain pine beetle. A healthy tree can forcefully push burrowing beetles out, but many of Colorado's pines are water-stressed and aging. Beetles have mass-attacked them, an onslaught that can overwhelm even healthy trees, Mack says.
North America is witnessing the largest pine-beetle epidemic in recorded history. From Canada's Yukon Territory to New Mexico, pine trees by the hundreds of millions are succumbing to a fungus that the beetles carry. The pine needles of infected trees first turn a violent red, then they fall, and, finally, the dead tree topples over. Year by year, communities have watched a scourge advance across mountainsides and through neighborhoods, trees turning from green to red to gray. The beetles now attack 12 pine species, from the high-elevation whitebark pine to the lower-elevation ponderosa and piñon. The blight has devastated 3.3 million acres in Colorado alone since the 1990s.
Beetles kill, die off, and regenerate, all of which is part of a lodgepole pine forest's natural life cycle. But human activity helped set the stage for the current epidemic. Decades of fire suppression have left the West with dense stands of vulnerable, elderly trees. Climate has also played a role. Frigid winters that usually kill the beetles have become, over the past 20 years, the exception rather than the rule. Earlier snowmelt and longer summers have altered the beetles' range and life cycle; they now attack pines at higher altitudes and latitudes, and they reproduce twice a year instead of once. Earlier springs and a series of dry years have also weakened trees, turning them into ideal beetle food.
Among the scientific community, a consensus is growing that changes in climate have propelled the outbreak. Jeff Mitton, an evolutionary biologist at the University of Colorado (Boulder), has been studying the mountain pine beetle for more than 30 years. There's no doubt in his mind that climate change has driven the infestation.
"The question is, why has this gotten so much worse?" Mitton said, with the placid gaze of a man used to thinking about long stretches of evolutionary time. "The beetles are out six weeks to two months earlier because springtime temperatures are warmer." Mitton connected the epidemic to other changes observed in American landscapes, from melting glaciers to shifting agricultural regions to increases in global temperatures.
But the evidence that Mitton and his colleagues are piecing together has yet to persuade many people in the U.S. Forest Service and the National Park Service, let alone the average Coloradoan, that climate change has driven the pine-beetle epidemic.
"There's a lot of discussion" about whether climate change influenced the epidemic, said Cal Wettstein, the Forest Service's incident commander who coordinates the regional response to the epidemic. "Of course, I'm not an expert on it. It's possible that it might be a factor. It's not the driving factor."
Mack says, "There's no question that we're seeing changes in different aspects" of ecological life at Rocky Mountain National Park. But he warned that the shifts aren't "the dramatic effects that people tend to associate with climate change."
Mack and Wettstein remain focused on dealing with an immediate consequence of the outbreak: keeping people and infrastructure safe from falling trees. Wettstein estimates that 100,000 dead trees will fall every day for the next 10 years in northern Colorado and southern Wyoming. A falling tree could kill a hiker, take out a power line, or block a back road.
It's tough to connect an ecological phenomenon to a single factor. It's also tough to predict the local manifestation of global warming in a mountainous state that sees a lot of weather variation. "I think that what's uncertain are the details," said professor William Bowman, director of the lab that Mitton and others use for studies of ecology and climate change. "What I see is not so much disagreement over whether climate change will occur; it's how it will be manifest."
Coloradoans have noticed that species are shifting their ranges, snows are melting earlier, and--particularly this year--warm weather is coming mighty early. Set aside the polarized climate-change debate, and you'll find communities dealing with a set of conditions that aren't obviously linked to rising global temperature and that don't, on a day-to-day basis, constitute a catastrophe. They're not yet seeing evidence that could spur action on carbon emissions. But if the climate models are correct, the changes that Coloradoans are already experiencing herald a very challenging future for the West.THE FIRE THIS TIME
The best way to view the effects of climate change in Colorado, it turns out, is from a car. Take Interstate 70 west from Denver toward Glenwood Springs, and you'll move from the Great Plains to high-altitude pine forest in an hour. As mountains unfurl and you drive into areas dense with lodgepole pines, the full visual impact of the epidemic asserts itself. New growth and untouched species amidst the devastation don't make the skeleton pines any less spooky.
The steep descent into Dillon presents perhaps the most dramatic sight on the highway. Cars shoot through the Eisenhower Tunnel, bored straight through solid mountainside, and pop out into a valley where in some places 70 percent of the trees are dead. Residents of Summit County have been grappling with a changing forest for almost a decade, and that has meant wrestling with fear, confusion, misinformation, apathy, and a sense of helplessness. In some ways, their experience is a microcosm of the larger climate-change debate.
A bum knee doesn't stop Howard Hallman, an earnest man kitted out in the Colorado uniform of fleece vest and sturdy boots, from clambering over the land that separates I-70 from Straight Creek. On one side of the stream, the mountainside is designated wilderness; on the other, it's designated roadless, making it almost impossible to drive tree-removal equipment in. A wildfire on either side could send dirt and debris tumbling into Dillon's only water source, but there's little residents can do--legally or logistically--to protect the creek.
"We have human habitat, we have housing, we have recreation, so we can't really let things run their course," Hallman said. Like a lot of Coloradoans, he worries that the dead trees heighten fire risk. Scientists dispute the extent to which beetle-kill trees affect fire behavior, but laypeople and experts alike are certain of one thing: In a dry year, the forest will burn. And this year looks to be extremely dry.
Hallman's community group, the Forest Health Task Force, worked with the Forest Service to clear-cut a 60-acre patch near Straight Creek, hoping to mitigate the fire hazard. The patch of bare ground looks pathetically small measured against the surrounding mountains.
From the brewpub where the task force meets each month, patrons can look out the window and see the Dillon Reservoir. The fact that the towns of Dillon, Frisco, and Silverthorne lie clustered around a reservoir that none of them can draw water from is a testament to the quirks of Western water appropriation. Constructed in the 1960s by Denver Water, the public utility for the state's capital, the Dillon Reservoir is Denver's property. Runoff from snows that blanket Summit County flows into the reservoir and then courses through the mountains for 70 miles to the sprawling metropolitan area on the plains. Summit County snowmelt that doesn't get siphoned off to local towns, Denver, or Colorado Springs eventually joins the Colorado River, the primary water source for close to 40 million people across the western United States.
The Forest Health Task Force long ago concluded that the pine-beetle outbreak can't be stopped. The citizens, environmentalists, politicians, and fire-service and water-utility officials who make up the group spent part of their May meeting talking about the threat that falling trees pose to infrastructure. They spent most of their time talking about drought.
"What we have now is a very dry year. It could possibly be a very, very serious drought," said Steve Swanson, head of the nonprofit Blue River Watershed Group. In a voice so soft that listeners strained to hear him, Swanson laid out what was on everyone's mind.
As of early April, Colorado's snowpack was 48 percent below average. Conditions haven't been this dry since 2002, the year made notorious by the Hayman fire, the largest in state history. That inferno burned more than 138,000 acres in the hills southwest of Denver and clogged the Cheesman Reservoir with an ashy slurry. The Western Forestry Leadership Coalition estimates that direct costs, rehabilitation, and other indirect costs of the fire topped $200 million. Ten years later, the rehabilitation effort is ongoing.
Colorado's 30 largest forest fires on record have all occurred since 1996, and state data suggest that fires have been growing in size as well as frequency. As this story went to press, New Mexico was fighting the largest forest fire in its history, a 46,000-acre blaze was burning in northern Colorado, and an 8,000-acre fire was spreading in southwest Colorado, near Durango.
At the meeting, Gibbs made a pitch for establishing "defensible space" around homes: a cleared area that stops fire from leaping from treetop to rooftop, or from bushes to front stoop. Defensible space is standard practice in Southern California, but it's not something Colorado policymakers and homeowners have thought much about until recently.
In Summit County, people are adjusting to a new normal. Longtime environmental stressors such as the pine beetle, drought, and wildfire have become more prevalent. Even people who believe that those changes are linked to rising global temperatures have a sense that bringing up climate change only polarizes and confuses the discussion.
Dan Schroder, director of the Colorado State University Extension in Summit County, heads a program that educates the community about fire risk and explains what's killing all the trees. But he'd rather not drag climate policy into it.
"I'm in the camp where climate change is happening, and it's something that we need to address and think about as we move forward," Schroder said. "But in order to engage with the general public, that sort of remains somewhat inflammatory, or a bit of a conflicting idea. So I tend not to engage that term 'climate change.' "
Hallman came to Colorado in 1972 to work as an engineer at the molybdenum mine up in Climax. He has been working as an environmental consultant since the late 1980s, but he's not a climate-change expert. He's a guy who cares about the outdoors and who's hungry for information about the changes he's seeing around his home. He's also worried that a confusing, sustained debate over whether the Earth is warming and why can only mean political paralysis.
"We have people who are saying, well, it doesn't exist, and not only it doesn't exist, but if you believe it exists, you are somehow--you are at least a socialist, if not a communist," Hallman said. "So that's not a good starting point."
"When it comes to allocating funding, like at the local level, if you have the misinformation ... how are you going to have the political will to take the actions that are necessary?" he asked. Another task-force member, Breckenridge-based environmental consultant Brad Piehl, feels the same way. "People need more facts. They need to sit down and talk about it," he said.
Mitton and other scientists might argue that those facts are already present, but at the local level, there is still room for doubt. People are watching new growth sprout around the dead pine stands. They know they live in a dry state. And even those who believe that reducing carbon emissions is necessary, like Hallman and Piehl, know that unless a majority of Americans feel that the same way, the national action needed to start that reduction isn't going to happen.
Locals can't do anything to stop the pine beetle's spread, just as they can't do anything, as individuals, to slow global carbon emissions. The way the pine-beetle outbreak will affect fire and water behavior remains murky, just as it's unclear how climate change will ultimately affect people's behavior about fire and water in the West. Advocates anticipate that more wildfires or water shortages could help convince people that climate change is here, and that it's a problem. But by the time scientists have proven the changes and everyone else has accepted them, more of us will already be living with the fallout.
"We're slowly, and maybe without even realizing it, adapting," said Lisa Dale, assistant director for parks, wildlife, and lands at the Colorado Natural Resources Department. The people in charge of managing the state's natural resources are dealing with climate factors even if they don't call their problem "climate change," she said.BOGGED DOWN
One of Colorado's U.S. senators, Mark Udall, has for years pointed to the beetle epidemic as the kind of evidence that conclusively shows climate change is occurring in plain view. But his and other lawmakers' efforts to move the needle on climate policy have gone nowhere.
"To a large degree, our nation's parks are the canary in the coal mine when it comes to on-the-ground effects of a warming climate," Udall said at a 2009 hearing on climate change that the Democrat held at Rocky Mountain National Park with Sen. John McCain, R-Ariz. At the time, Udall pointed to "trees killed by a bark-beetle epidemic that has been exacerbated by a warming climate."
Three years later, Udall is still calling Colorado's forests "canaries in the coal mine for the effects of a warming climate." In a statement released by his office last week, the senator said, "We need to look into understanding the very real impacts that affect the health of our resources and our ability to protect them."
Udall supported the Senate draft of a highly contentious bill to "cap and trade" carbon emissions. After a mad scramble for votes, the legislation barely based the House in the summer of 2009. It soon bogged down in the Senate--largely because of coal-state Democrats' fears that the legislation would damage their local economies and open them to political attack.
Their fears were justified. Scores of House Democrats lost their seats when opponents and interest groups pounded them with their cap-and-trade vote, along with votes on health care reform and other Democratic priorities. Even some who had opposed cap-and-trade fell victim.
"Candidly, I think the Republicans--who were in the minority--saw the opportunity to use this bill to make inroads," said Rick Boucher, who represented a district in Virginia's coal country for 28 years before losing his seat in 2010. Attack ads hammered swing-district Democrats like him for their cap-and-trade votes, Boucher said. He was particularly vulnerable because he chose to try to help craft a bill that would strike a balance between regulating emissions and protecting industry back home--the very thing we expect responsible lawmakers to do. "It was a factor in my race," Boucher said.
Since the cap-and-trade bill faltered, Congress has shown little inclination to act. The Republican Party seems more dug in on the matter now than ever, with most GOP lawmakers publicly doubting evidence that human activity is warming the planet, opposing any regulation that would curb fossil-fuel use, or both.
The party's standard-bearer, presumptive presidential nominee Mitt Romney, openly distanced himself from the science of climate change in remarks to donors in Pittsburgh last fall. "My view is that we don't know what's causing climate change on this planet. And the idea of spending trillions and trillions of dollars to try to reduce CO2 emissions is not the right course for us," Romney said.
Even Colorado Republicans in Congress, who see sickly forests on a regular basis, refuse to tie the beetle infestation and drought to human activity and resist the idea of regulating carbon emissions.
In May 2012, GOP Rep. Scott Tipton held a field hearing on the bark beetle in Montrose, in the southwest part of the state. At the hearing, he blamed "federal obstruction" and mismanagement of Colorado's forests for the beetle epidemic and called for more timber extraction to thin aged pine stands. Federal mismanagement, Tipton maintains, is the primary driver of the beetle outbreak.
He says that the climate has been changing throughout history and that there's still debate over the role human activity has played in current shifts. "We've got to be responsible," the lawmaker said, when reached by phone at his office in Washington. "We've got to be able to create jobs; we've got to be able to provide energy." Even if the United States and Europe both stopped emitting carbon for the next 25 years, the difference would soon be made up by other nations, Tipton said.
Rep. Mike Coffman, another Colorado Republican, said: "Climate change is naturally occurring. What influence do we have over that, we certainly need to look into, but that's subject to debate."
Tipton and Coffman (and Romney, for that matter) have plenty of company. Fifty-two percent of Americans believe that the effects of global warming have already set in, according to a March Gallup Poll, down from a high of 61 percent in 2008. Forty-one percent believe that the climate is changing because of natural causes, compared with 53 percent who blame human activity. The number of people who say that human activities are the primary cause of global warming has dropped 8 percentage points since 2003.
While the debate rages on, the climate of the Rockies continues to transform, with consequences that will reverberate nationwide. Stream flow in the Colorado River basin is expected to decrease over the next 50 years, purely as a result of precipitation and temperature changes, according to the U.S. Bureau of Reclamation. The median projection anticipates a 9 percent decrease from the historical mean by 2060, said Carly Jerla, a co-manager for the Colorado River Basin water supply and demand study. "There will be more extreme highs, more extreme lows," she said, "all trending toward a lower, decreased overall mean." Over the same period, the bureau predicts that the human population dependent on the Colorado River for drinking water will rise from the current 40 million people to between 49.3 million and 76.5 million.
Significant economic effects could follow. Experts warn that changes could disrupt a thicket of local and regional water-rights agreements and necessitate expensive infrastructure changes. Agriculture across the West could experience a major hit as growing conditions change and water supplies shift. In mountain towns, such as those in Summit County, the omnipresent recreation industry may have to cope with less-than-epic snowfall.
Despite the alarming predictions, communities in Colorado and elsewhere don't yet feel that they're living the future that climate models predict. A full-throated call for action in Washington seems unlikely, no matter how often advocates try to provoke one.
"We have to have a two-pronged approach," said Rep. Diana DeGette, a Democrat whose district is primarily the city and county of Denver. "If you just try to deal with the practical issues without the underlying cause, then over time, the situation on the ground is only going to worsen for our state. ... From a congressional standpoint, what we should be doing is trying to steer our public policy so we move away from fossil fuels."
Right now, Colorado's congressional delegation is working to address the effects of the beetle outbreak--not the changing climate that's helping drive it. But Boucher said he believes that Congress, rather than the Environmental Protection Agency, should again attempt to act to regulate carbon emissions, because EPA can't create a "buffer against economic disruption" like Congress can. The threat of EPA regulation-by-fiat could help build bipartisan consensus for action--if only there were consensus that the problem exists in the first place.
For now, the political cost of action remains too high and the economic incentives for taking drastic measures too low. Until that dynamic shifts, supporters of climate-change policy will have to marshal their facts and continue to point to episodes such as the beetle infestation to try to convince those on the fence. Scientists worry that by the time evidence becomes undeniable and political will has amassed, it will be too late for reducing emissions to make any difference. Many worry that the tipping point for action has already passed.
To cope with a changing climate, communities from Denver to Dhaka need to do two things. Adapt, step by step, to the new normal, and move, step by step, away from burning fossil fuels. Little incentive exists to make punishing changes to the economy while the evidence of climate change remains opaque to so many people. But by the time the evidence overwhelms us, millions of trees will be rotting on the ground.
We want to hear what you think about this article. Submit a letter to the editor or write to firstname.lastname@example.org.