A changing climate may present a double-edged sword for Rocky Mountain National Park and the Estes Valley, according to a three-year Colorado State University study.
The study, sponsored by the U.S. Environmental Protection Agency’s Science to Achieve Results program, applied the widely used Canadian Climate Center and Hadley global climate models that indicate Rocky Mountain National Park will face milder winters and warmer summers in the future. A team of researchers from Colorado State in the areas of economics, wildlife biology, resource economics and forest sciences studied the impacts of the predicted climate change on the economy, potential changes in fire activity and the impact on wildlife in Estes Park and RMNP.
The overall findings of the study include the potential for loss of species and habitats, more pest species and increased fire frequency and intensity due to a changing climate. The study also found potential for major landscape changes that could alter the perceptions and quality of experience for visitors to RMNP and Estes Park. However, the longer recreation season would result in a slight increase in the number of visitors to the area, which would be beneficial for the local economy.
The study also found that the changing climate produced the potential for reduced tundra areas in RMNP. Tundra exists because low temperatures and short growing seasons limit the tree line. In the past, the tree line has moved up and down the slope in response to long-term temperature change. Future global warming could raise the tree line and eliminate tundra in parts of the Rocky Mountains, which also would have impacts on wildlife that depend on these areas, such as ptarmigan, whose numbers are expected to decline with the warming temperatures.
The impact to wildlife includes the likelihood that climate change could increase the abundance of elk. The increases likely will accelerate declines in woody plant communities, such as willow.
"The climate change may intensify current stressors with the elk population in the park," said Tom Hobbs, a lead researcher on the study and scientist at the Natural Resources Ecology Laboratory at Colorado State. "A lack of cold winters is likely to cause dramatic increases in the number of elk, and park managers will have to determine alternative elk management."
The endangered greenback cutthroat trout in the park could respond positively to warming temperatures that allow earlier spawning of the fish. The earlier spawning increases the time interval when trout can grow, and the increased time for growth enhances translocation success. However, temperature increases could boost potential for whirling disease among the trout population.
Colorado State researchers looked at changes in fire regimes – how often fires occur – in the park and how they may change in the future due to warming temperatures related to climate change. The study found the number of fire ignitions will likely increase under future climate scenarios, but the full consequences of fire regime changes will depend on complex interactions among climate and disturbance events that may alter landscape patterns in the park.
The impacts of climate change on the local economy of Estes Park also was studied by looking at visitation and employment numbers and local sales and how those areas may change under different scenarios of future climate. Colorado State economists John Loomis and Stephan Weiler received a 70-percent response rate on a survey given to 1,266 visitors concerning recreation in RMNP in an increased temperature scenario.
The survey found that the warming climate would attract more people to the park, which relates to more money being spent in Estes Park and at RMNP, increasing employment in the area. Under an extreme heat climate scenario, similar to the past two summers in Colorado where many days were over 80 degrees, the number of visitors was projected to decline and negatively impact employment and sales.
"Small increases in temperature will result in a lengthening of the recreation season and increase visitation, especially in the fall and spring," said Loomis. "However, as the past summer demonstrated, large increases in temperature might reduce visitation. In this case, a little might be good for visitors, but a lot is bad."
"We’re not absolutely certain that temperatures will increase as much as the climate models are forecasting," said Hobbs. "This study provides management options to deal with issues regardless of how much the climate changes."