Climate Change Is Taking Its Toll on America’s First National Park

Yellowstone National Park, like much of the world, is displaying definitive signs of the impact of global warming.

That was the conclusion of a team of researchers from the U.S. Geological Survey, the University of Wyoming, and Montana State University following a recently-published study analyzing the environmental threat facing down the greater Yellowstone region.

Looking at data collected between 1950 and 2018, the cohort found that average temperatures throughout the region increased by 2.3 degrees Fahrenheit. At that rate, the authors wrote, temperatures in America’s first national park, which opened in 1872, could increase between 5 to 10 degrees Fahrenheit by 2100.

“Greater Yellowstone is valued for its forests, rivers, fish and wildlife,” wrote Steve Hostetler, a USGS scientist and one of the lead authors of the report. “The trend towards a warmer, drier climate described in this study will likely affect ecosystems in the region and the communities that depend on them.”

Yellowstone’s surplus of fish, elk, and bison could face an especially uphill battle if temperatures continue along this current trajectory.

“Climate change directly affects bison by increasing thermal stress and decreasing forage and water availability, issues that also challenge range beef cattle,” wrote Jeff Martin, South Dakota State’s director of research for the Center of Excellence for Bison Studies.

“Indirect consequences of climate change include increasing distribution and intensity of parasites and several diseases that are known to reduce reproductive success. These stresses have been estimated to collectively reduce bison body size by 50% if global temperature warms by 4°C near the end of the 21st century.”

And while warming climates are by now well documented, temperature trends, according to the study, have never been more dire.

Geological data gathered during the study’s timeframe suggests that average temperatures in recent decades are “as high or higher than any period in the last 20,000 years and likely the warmest of the last 800,000 years.”

Coinciding with that dramatic increase has been a substantial drop-off in snow accumulation. Since 1950, the average annual snowfall in the greater Yellowstone area has dropped 23 inches, the study’s authors found.

“The decrease in snow is due to the increase in temperature over time, which caused more precipitation to fall as rain instead of snow,” said University of Wyoming’s Bryan Shuman, who co-authored the study.

Coupled with elevated temperatures and higher evaporation rates, a shift from snow to heavier rain will likely yield drier conditions that can diminish soil moisture and, in turn, degrade plant and animal ecosystems as the region becomes more susceptible to wildfires.

These concerns, the authors wrote, warrant more climate monitoring initiatives capable of mitigating and projecting impacts on the region’s waters, wildlife, and communities that depend on both.

Read more from the full study here.