Climate Change in the Greater Yellowstone Ecosystem

The first major climate assessment focusing on the Greater Yellowstone Ecosystem (GYE) forecasts rising temperatures for the entire ecosystem over the next 50 years. These climatic changes are predicted to shrink the snowpack and change the timing and rate of snowmelt. The draft study titled the Greater Yellowstone Climate Assessment: Past, Present and Future Climate Change in Greater Yellowstone Watersheds indicates that there has been a steady decline in snowpack since the 1980’s, raising concerns for wildlife and for the communities that depend on GYE snowpack for their water supply. A related investigation hypothesized that reduced precipitation may limit the subsurface supply of water to the old faithful geyser basin and cause a cessation of eruptions, similar to what happened in the 1300’s (Hurwitz et al. 2020). 

Other predicted shifts include changes in grassland habitats which may alter migratory patterns for bison and other ungulates. This in turn, can affect large carnivores who rely on migratory mammals for food. One large carnivore that may be affected is the grizzly bear, which relies on Whitebark Pine as one of their main food sources. Whitebark Pine is already in decline due to rising temperatures and this study predicts that trend to continue. Changes in temperatures and precipitation may also yield unstable food availability for temperate songbirds. Other risks include invasive species outbreaks and drier conditions making the region more prone to wildfires.

This peer-reviewed extensive study of the GYE highlights the importance of scientific research on climate change and its risks for public lands, wildlife, and human health. The Greater Yellowstone Area is one of the largest remaining intact temperate ecosystems on Earth, and it deserves to be protected. The report, produced by researchers from Montana, Wyoming, and Idaho in partnership with the US Geological Survey and National Park Service is a much-needed source of climate change information which can help communities, policy makers, and natural resources managers plan for the future. Its coverage of past, present, and future climate change and water resources in the GYE provides baseline information for future assessments of the climate impacts on wildlife and forests in the region, as well as our social-economic well-being and human health. This comprehensive study is one step towards reframing our priorities and future resource goals as we face climate change together.



Hurwitz, S. (2020, October 7). Yellowstone's Old Faithful Geyser Shut Down by a Severe Thirteenth Century Drought. US Department of the Interior. 

Hostetler S., Whitlock C., Shuman B., Liefert D., Wolf Drimal C., and Bischke S. (2021, June) Draft GREATER YELLOWSTONE CLIMATE ASSESSMENT Past, Present, and Future Climate Change in Greater Yellowstone Watersheds. Montana Climate Assessment.

Photo of bison in Yellowstone National Park by Dan Dorsch