Warming signs add up, experts warn
SUMMIT COUNTY – Rising global temperatures could play out in significant ways in the Colorado High Country, with impacts such as snow melting earlier, a less reliable water supply and a loss of spectacular alpine scenery, a panel of experts said Thursday evening in Frisco.The climate change forum included a presentation from Denver Water resource manager Marc Waage, who said that even a two-degree rise in temperatures could result in a six percent drop in water supplies and a 12 percent increase in demand.Those numbers were based on a vulnerability study recently completed by Denver Water, but even if the figures aren’t spot on, the state’s biggest water supplier is looking at ways to reduce the threat of global warming, Waage said.”If the pie shrinks, our piece is most vulnerable,” Waage said.
Resource managers have traditionally based their projections on data from past years, but with the uncertainties stemming from climate change, that approach may not work, Waage said. The two degree increase in temperatures used in the Denver Water study may be the best-case scenario for the Rocky Mountains. Some projections included in the recent international report on global warming show wintertime temperatures in the West climbing by six to eight degrees during the next 50 to 100 years, with summer temperatures edging up seven to nine degrees.Warming temperatures during the past few decades have already contributed to a measurable change in when snow melts, said U.S. Geological Survey researcher Dave Clow.Those findings tied in neatly with data presented by climate researcher Klaus Wolter, who has pinpointed a marked warming trend in Colorado’s north-central mountains, with warming most apparent during the spring months. It’s not getting nearly as cold as it used to in the area, and the warning signs include a shrinking snow cover in the northern hemisphere, he said.
“The absence of snow could exacerbate the warming trend,” Wolter said. “There is a very intimate coupling between snow cover and temperature.” The volume of global ice is also diminishing, and the rate of that change could still result in some unexpected consequences, he added.”There’s room for surprises,” Wolter said, adding that about 90 percent of the scientists think it will be wetter in the winter and drier in the summer.A climate action plan is being developed for Colorado that includes an emissions inventory and forecast, said Tom Easley of the Rocky Mountain Climate Organization.The group hopes to complete its plan by the end of the year, and Easley said the Ritter administration appears to be receptive to turning those recommendations into legislative action next year.
While the challenge is global in scale, taking action in Colorado is important in the scheme of things because the state produces more greenhouse gases than all but 38 countries in the world, Easley said.The western U.S. could take the brunt of the warming, with average temperatures climbing by almost another two degrees by 2040. That could mean 24 percent less snow in the region and 36 percent less storage in the Colorado River Basin.The good news is that many of the actions required to reduce greenhouse gas emissions have positive side effects, including the creation of new jobs, less sprawl and lower energy costs for consumers, Easley said. Photographer and conservation advocate John Fielder made an emotional plea to act now to save Colorado’s spectacular alpine scenery, describing how, in the course of his work, he’s already noticed forests creeping up higher into the tundra and alpine zones. “It could be gone by 2050 as the subalpine zone moves higher,” Fielder concluded.