Greater Yellowstone
Coordinating Committee

​Threat to the Ecosystem:

Climate change is arguably the most pervasive conservation threat to the Greater Yellowstone Ecosystem (GYE). Fish kills in the Yellowstone River, the spread of aquatic invasive species, rapidly increasing invasive grasses, shrinking wetland resources, and extreme wildfire behavior with impacts to aquatic resources have all been linked to a warmer, drier climate. The climate-amplified floods of June 2022 destroyed roads, trails, and bridges across the GYE, most notably in the northern range of
Yellowstone National Park and Paradise Valley and Red Lodge, MT, heightening the awareness of managers and the public to the climate change threat.

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Status and Trends in Greater Yellowstone:

Since 1950, average temperature increased in the GYE 2.3°F, peak precipitation shifted from May/June to April/May, average snowfall declined by 3.5 inches, and the timing of peak flow now occurs about 8 days earlier. Warming trends are projected to continue by +0.5°F to +1.2°F per decade, water stored in the snowpack is expected to continue to decrease, and a further decline in soil moisture of 5–7% is projected by mid-century. GYE climate change trends and projections include:
 

Increasing economic loss and community disruption due to damaged and lost infrastructure as climate related events become more common or extreme.
Increased extreme precipitation and drought events are projected. In wet years, increased rain on snow events will lead to more flooding and damaged infrastructure. After prolonged dry periods, increased fire events are likely in the wildland urban interface.
 

Shifts in recreational opportunity and tourism due to rising temperatures.
Temperature has increased by 2.3 °F, and snowfall has decreased by 25% below 8,000' since the 1950s. With warming temperatures, visitation may increase up to 140% during peak season and expand into shoulder seasons. But increased smoke due to a lengthening fire season and decreased snowpack may decrease summer and snow-related tourism.
 

Declines in native fauna and flora populations and increase in ecosystem stress and shifts.
Peak stream flow is 8 days earlier than in the 1950s. Lower base flows are coupled with increasing temperatures. Early spring runoff and warmer/lower late season flows are negatively affecting cutthroat trout, threatening the species’ persistence. Vegetation communities, and native bird, amphibian, and wildlife populations are also or may be impacted.

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Publications/Products Produced:

The GYA Climate Explorer: For each of seven climate variables, the GYA Climate Explorer compares the average of historic (1916 – 2006) climate values to a mid-century (2030 – 2059) projection with:

• historic and mid-century maps with a slider bar to compare the two

• a delta map showing change for each pixel value

• and a bar graph or pie chart showing a comparison of the historic and mid-century values

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Climate Analyzer for the GYA: Make custom graphs and tables with data that is updated every 24 hours from these sources:

• National Weather Service COOP Network

• Remote Automated Weather Station (RAWS)

• NRCS Snow-Telemetry (SNOTEL)

• USGS Stream Gage

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Greater Yellowstone Climate Assessment: Past, Present, and Future Climate Change in Greater Yellowstone Watersheds

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Greater Yellowstone Climate-Aquatics Workshop: Report from the April 27–29, 2021, Climate-Smart Conservation Workshop.

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GYCC-Fisheries Subcommittee Project Checklist (PDF) (Word)