The Perils of Climate Change in Greater Yellowstone
The jagged peaks of the Gallatin Range towered thousands of feet above us.
As we stood next to a talus slope, a large formation of rocks and boulders piled high, I could see April’s breath in the crisp autumn air as she talked about pikas and their habitat. I was amazed that summer had given way to fall in a matter of days. The aspen trees and other broadleaf plants were now brilliant shades of yellow, orange, and red-- colors made even more dramatic when viewed against the backdrop of a clear blue sky.
In honor of National Public Lands Day this past weekend, a group of Sierra Club members and friends from Bozeman, Montana, trekked into the Gallatin Range of the Northern Rockies to learn about climate change and its effects on pika populations. April Craighead, a wildlife biologist and pika researcher at the Craighead Institute based in Bozeman, hosted us on a tour of one of her research sites in the Greater Yellowstone Ecosystem (GYE).
Pointing towards the mass of rocks, she explained, “The talus slope offers cover from predators, as well as protection from warm temperatures which can be lethal to pikas.” Once referred to as “little chief hares” in the 19th century, pikas are the smallest member of the rabbit family, and as April explained, they’re extremely sensitive to heat. Temperatures above 80 degrees can kill pikas in as few as 8 hours.
“Eep, eep, eep,” chirped a pika on patrol. We had been spotted, and now the entire colony was on high alert.
The GYE is the largest intact temperate ecosystem left in the northern hemisphere of planet earth. It covers approximately 36,000 square miles in Southwestern Montana, Eastern Idaho, and a large chunk of Wyoming. It’s an icon of the American West, a land of raging rivers, sagebrush covered plateaus, and some of the most remote and rugged mountain terrain found anywhere in the United States.
Millions of tourists flood into Greater Yellowstone each summer to experience the beauty and mystic of its pristine wilderness. While the casual visitor might miss the drastic ecological changes that are happening in the area, a warming climate is quickly altering Greater Yellowstone in ways that will profoundly affect its future.
As the region’s climate continues to warm, pikas will be forced to retreat higher up the mountains to escape the lethal warmer temperatures. April has already documented these migrations, and they serve as a testament to the reality of a warming climate in Greater Yellowstone.
She believes that the high altitude of the Rocky Mountains will serve as a refuge for the temperature sensitive creatures. Other species, such as the whitebark pine, won’t be so lucky.
Entire whitebark pine forests throughout Greater Yellowstone are rapidly dying. Milder winters have given rise to an epidemic of mountain pine beetles on a scale never before seen. These beetles, no longer held in check by fierce winters, bore into the trunks of pine trees leaving a trail of destruction in their wake. Since 1997, an estimated 62,500 square miles of Western pine forests have been decimated by this epidemic.
Jesse Logan, a retired bark-beetle researcher for the U.S. Forest Service, recently told a reporter from the Salt Lake Tribune that the whitebark pine will be functionally extinct from Greater Yellowstone within a decade. “These forests are enchanting places,” Logan said. “[Yellowstone] just captured my imagination and my heart, and it breaks my heart to see what’s happening in these high-elevation, old-growth forests.” The endangered grizzly bears of Yellowstone depend on the high-protein pine nuts as a staple in their diet. As the pine nuts disappear, bears will continue to move to lower elevations in search of other food sources, and this is likely to increase bear/human conflicts.
Whitebark pine forests also provide shade to high alpine snowpack. As the forests that hold snow in place die off, we will also see increased spring runoff resulting in more floods and lower water levels and warmer summertime temperatures for many of the area’s rivers. This is not good news for the legendary coldwater fisheries of the Yellowstone, Snake, Madison, and Gallatin Rivers.
Ecosystems are complex webs, and even the best science of the day is inadequate at predicting the ripple effects that warming temperatures will cause throughout Greater Yellowstone. While no one knows for sure what will happen, it’s not going to be good for Yellowstone.
Today, the Rocky Mountain Climate Organization and the Greater Yellowstone Coalition released a grim report about climate change within the GYE. This past decade was the hottest ever recorded in Yellowstone National Park, and the study predicts that unless we quickly stem greenhouse gas emissions, summertime temperatures are likely to rise by nearly 10 degrees within the next 60-90 years. If this happens, the Yellowstone of the future will bear little resemblance to the current park that millions of visitors flock to see each summer.
The Sierra Club’s Resilient Habitat campaign is working to better understand the specific effects of climate change in Greater Yellowstone. This type of knowledge, such as where grizzly bears are likely to migrate in search of new food sources, helps our campaign prioritize areas and migration corridors that are most in need of protection.
Protecting and connecting large swaths of wild intact land allows species to have sufficient room to move, and this is the one of the best way to give pikas and other species a chance to thrive in a rapidly warming world.