The national monument manager, she said, wanted nothing to do with any discussion of climate change. It was still a touchy subject among federal land managers.
That has changed. In broader society, there was a “tipping point” in attitudes about climate change about 18 months ago. Some say it was because of Al Gore’s movie, or perhaps the polar bear pictures, or even the latest International Panel on Climate Change report, which stated with 90 percent confidence that humans were at least partly responsible for the changing climate.
Whatever the cause, society has become more aware of the impacts of climate change, and now federal land managers and other scientists have, too. “It’s something new in the last six months,” said Millar, a principal organizer of a gathering of mountain climate and ecosystem scientists held for three days last week in Silverton.
The conference, which was hosted by the Mountain Studies Institute, attracted more than 120 scientists from universities and federal agencies across the North American West, as well as assorted others. Dozens of PowerPoint presentations were given in Silverton’s tin-ceiling town hall meeting room. Nearly all were focused specifically on climate change and mountains.
Some ideas were simple in their expression, complex in their implications. Such is the case with water. Some 60 to 80 percent of precipitation in the West arrives in the mountains in the form of snow. Even drizzly Seattle depends on snow in the Cascades.
Most impressive of all is the Colorado River Basin, which includes the Animas, Dolores, Uncompahgre, and other rivers that cascade off the western flanks of the San Juan Mountains. The Colorado River and its tributaries provide vital sustenance for everywhere from the haciendas of San Diego to the cornfields of Nebraska, up to 34 million people by some estimates.
Forecast: Shorter Winters
Water managers have always assumed that they were planning for a future that looked something like the past. In the West, that’s a limited rear-view mirror. We have only 100, maybe 150 years of records. But this new evidence of climate change is forcing a reassessment, a firm nudge to the idea that the future won’t necessarily look like the past.
What the future is almost sure to bring is more heat – much more than the rise of recent decades. “The American West will be the epicenter for warming,” said Roger Pulwarty, of the National Oceanic and Atmospheric Administration in Boulder.
Whether the future will bring more snow, or less, remains uncertain. Warmer clouds can carry 30 percent more precipitation, which might mean lots of snow. Unlike the computer models that show heat, forecasts regarding precipitation are murkier. The only clear message is that winter will, on average, be much shorter – as it already is in California’s Sierra Nevada, where runoff is typically 20 days shorter.
More isolated sampling conducted by David Clow, a scientist with the U.S. Geological Survey, also finds earlier runoff during the last 30 years in Colorado, but with a stronger signal in the San Juans.
One of the problems with forecasting changed precipitation as the globe warms is because of the coarseness of computer models. The several dozen models show broad trends, such as heat. But precipitation in the West depends so much on interaction with mountains. The earlier computer models showed the Rocky Mountains as only slight bumps, like the highest point in Kansas.
Now, computer modelers are working hard to come up with models that will provide a finer scale. Instead of grids every 50 kilometers, they hope to have models of only a few kilometers. That still isn’t the sort of resolution that will show the verticality of an Eolus, Vestal Peak or El Diente, but it will be a marked improvement.
The Chipmunk Factor
The presentations about climate modeling in Silverton were of the level of complexity to leave even somebody who survived high school calculus and trigonometry with crossed eyes. Easier to grasp were the reports about phenological observations, such as the first appearance of chipmunks in spring.
David Inouye, a biologist from the University of Maryland who summers near Crested Butte at the Rocky Mountain Biological Laboratory, said a diary kept by a scientists there since the 1970s reveals a clear shift in spring beginning in about 1998. The snow is melting more rapidly in most years, April is becoming significantly warmer, and ground squirrels, marmots and other small animals are appearing earlier.
But not all animals respond in the same way to warmer temperatures of spring. For example, while marmots have been appearing in April, recurrent cold may be causing increased mortality.
The sponsor of the conference was the Consortium for Integrated Climate Research in Western Mountains, or Cirmount. The goal of the group, in part, is to create a better and expanded network of monitoring stations in high mountain locations. The argument of proponents is that the mountains are like canaries in coal mines, which were used to detect dangerous concentrations of poisonous methane gas. In this case, mountains are earlier predictors of changes to come at lower elevations. Already, high-mountain temperatures have increased far faster than in the valleys.
Colorado only has two mountain monitoring stations, one at Niwot Ridge, northwest of Boulder, and the second in Senator Beck Basin between Silverton and Telluride. The latter is maintained by Chris Landry’s Center for Snow and Avalanche Studies.
An Uncertain Future
The essential question is of adaptation – a difficult proposition when the future remains so uncertain. “Everybody talks about adaptation, but nobody really knows how we should go about it,” said Hans Schreier, of the Institute for Resources & Environment at the University of British Columbia.
But in fact, Schreier and other scientists do realize some adaptations can be made now. For example, global warming is likely to produce more intense storms. For the rapidly growing mountain towns in the Columbia River Basin of British Columbia, that suggests a need for more innovative approaches for urban stormwater management. Expansive asphalt parking lots, for example, might best be interspersed with swales where storm waters will be allowed to more slowly dissipate.
Last Thursday, land managers and others from the San Juans heard from Koren Nydick, executive director of the Durango-based Mountain Studies Institute. The warming trend in the San Juans from about 1990 is clear, even if the impacts of that warming are not, she said.
Millar, the paleoecologist, also spoke to San Juan land managers. She said decisions must be made about how to manage forests and rivers, knowing the future will not look like the past, but not knowing exactly what the future will look like.
“Practice ecological management outside the box,” she said. She advised a mix-and-match collection of tools. “No single solution fits all cases.”
Later, reflecting on her last 20 years as a scientist in a federal agency, she said it was difficult to get a conversation going with managers. She was, for example, among the first people talking up the increase in forest fires as a consequence of changed climate. Such talk was initially dismissed.
Now, climate change is being taken seriously – and everybody wants to know how to manage lands in this new regime. “A year ago the door flung open, we fell in, and they said, ‘Now what do we do?’” said Millar.
The short answer is that nobody has all the answers. The past is clearer than the future. The only trouble is, the past is no predictor of the future.