Environmental Issues: Wildlands

Warmer, drier conditions in the Rockies could degrade this park's iconic tundra and threaten wildlife, wildflowers and winter sports.

Standing above the treeline and gazing at the jagged peaks of Rocky Mountain National Park, you discover what it feels like to be at the top of the world. It's windy, the sun beats down hard, and the weather could turn in an instant, but the sense of soaring space and sky is exhilarating. Rocky Mountain National Park is defined by extreme cold, heavy snowfalls and expansive tundra -- all of which are likely to change in a warming world.

Rising Temperatures Threaten the Park's Signature Tundra

As many as 2 million visitors each summer drive up Trail Ridge Road to enjoy the largest and most accessible expanse of alpine tundra in the lower 48 states. The severe winter chill and short growing season prevent trees from taking root here, but wild grasses, bountiful flowers and the wildlife they support flourish in these conditions. However, all this could change soon. Researchers project that global warming could cause the treeline in the park to encroach on the tundra by nearly 250 feet for every degree of warming. A 5.4-degree rise in temperature is projected to eliminate half the park's tundra; with warming of 9 degrees to 11 degrees, all tundra might be eliminated from the park. Without tundra, park visitors will face different scenery: forests climbing up mountaintops instead of an open expanse filled with grasses and wildflowers.

Mountain harebells in bloom, Rocky Mountain National Park

Milder Winters Put Pressure on Cold-Weather Wildlife

The same warming trends that could endanger tundra will also disrupt the wildlife that has learned to live in cold-weather conditions. The park's population of white-tailed ptarmigans -- famous among birdwatchers -- depends on deep snow to survive the alpine winter, using the natural insulation of snow caves to keep warm, and using snow pack like a ladder to reach willow shrub branches for food. But now, presumably as a result of earlier and warmer springs, young white-tailed ptarmigans hatch significantly earlier, leaving them vulnerable to low alpine food supplies and sudden temperature swings. In just two decades, the birds' numbers have been cut in half, and researchers say that if temperatures rise as predicted, the birds could become extinct in Rocky Mountain National Park by mid-century. Other alpine species popular with park visitors, such as pikas and marmots, may face similar struggles.

Warmer Weather Leads to Less Colorful Mountain Meadows

When the alpine meadows of Rocky Mountain National Park are in bloom, a magnificent blanket of violet, pale blue and deep red wildflowers lights up the gray monochrome of mountain peaks. But a warning about the future of the park's wildflowers comes from the Rocky Mountain Biological Laboratory, in the mountains near Crested Butte, Colorado. There, researchers have used overhead heaters since 1990 to simulate the effect of a 4-degree increase in temperature in alpine meadows. The warming stretched out the snow-free growing season by two weeks in both spring and autumn, heated up soil temperatures and dried out soil moisture -- changes that led to a substantial drop in wildflowers. Shallow-rooted flowers were especially at risk, overtaken by the dull-colored sagebrush of drier lands. Warming could produce the same result in Rocky Mountain National Park and other mountain parks across the West.

Drier Conditions Fuel the Risk of Severe Wildfires

Global warming lays the groundwork for more frequent and more severe fire seasons. Scientists predict that the rising temperatures, drier summers and longer droughts brought on by climate change could increase the number of wildfires started by lightning in Rocky Mountain National Park by 50 percent to 92 percent. Recent history vividly illustrates how wildfires can spoil summer park vacations. In 2002, one of Colorado's worst fire seasons, the number of July visitors to the park dropped by nearly 100,000 from the previous year, even though there were no fires in the park itself.

Diminished Snowfall Puts a Damper on Winter Recreation

Thousands of cross-country skiers and snowshoers come to the park each year from among the 2.5 million people living in Denver and other Front Range cities. But this winter fun is dependent on heavy snow cover, and climate scientists predict that as global warming continues, winter will start later, end sooner and bring lighter snowfalls. For instance, researchers project that in the park's Loch Vale basin, near popular ski and snowshoe trails, a 7-degree increase in temperature could lead to a 50 percent reduction in the basin's snowpack.