A growing list of studies show that global climate change will mean less water in the Colorado River, but varying perceptions about climate change are a hurdle to making decisions about future water supplies.
That was one message delivered Tuesday evening in Aspen by Dr. Eric Kuhn, general manager of the Colorado River Water Conservation District. Kuhn spoke at the Aspen Global Change Institute, which is hosting a workshop this week to explore how climate scientists and water managers can provide better information to government decision makers.
Kuhn cited a survey done six months ago by the Rocky Mountain Climate Organization of people in the seven states that have a stake in Colorado River water, including Colorado, Utah, Wyoming, Arizona, New Mexico, California and Nevada.
The survey asked residents of those states, “Is climate change an established reality or an unproven myth?”
People in Colorado are split 47 percent to 47 percent on the question.
In Wyoming, only 35 percent of people think climate change is “an established reality,” while 62 percent of Californians think it is.
Seventy-four percent of Democrats in those seven states think climate change is a reality, but only 25 percent of Republicans do, the survey found.
Kuhn said another survey found that in the 15 Western Slope counties that make up the Colorado River District, 83 percent of Democrats feel climate change should be given a high priority, while only 40 percent of Republicans felt the same way.
Yet Kuhn said evidence continues to point to a future with hotter temperatures and less water in the Colorado River.
He cited a recent study by the Colorado Water Conservation Board that clearly stated there would be a decline in runoff for most of the Colorado River basin by the mid-21st century.
“It is simple and very straightforward,” Kuhn said of the CWCB finding. “You think we should be able to do something based on the advice, but we are not quite there.”
A recent preliminary water supply study by the CWCB showed that by 2040, there would likely be an 8 percent reduction in average annual runoff in the Colorado River above Grand Junction. And that the runoff will likely come a week earlier.
“Science is never going to tell us how much water is going to be in the Roaring Fork to the nearest cubic foot per second in December 2020 or 2021, but it is going to tell us there may be less,” Kuhn said. “So when do we start making a decision based on evidence that is pretty clear, and pretty overwhelming, yet there is a lot of uncertainty?”
Kuhn said in his position at the river district he is non-political, but also said he is not shy about pointing out how political differences are a hurdle to developing sound water policy.
He said “there is not yet a public consensus on climate change and whether we need to do anything about climate change.
“There may be in some communities like Aspen or Glenwood Springs, where I live, but there is not in places like Grand Junction. There still is a political divide. And if we don’t talk about it, we won’t bridge that political divide,” Kuhn said.