National Park Service

State of the Park Reports

State of the Park Report for Zion National Park

Resource Brief – Future Climate Projections

Climate change affects all aspects of park management from natural and cultural resource protection to park operations and visitor experience. Effective planning and management must be grounded in our comprehension of past dynamics as well as the realization that future conditions may shift beyond the historical range of variability. For example, at Zion National Park average annual temperature (30 year mean) is projected to be higher than the 1971–2000 average under all future time periods and both low and high greenhouse gas emission scenarios (see Figure below). Climate projections for Zion suggest that, by 2100, mean annual temperature may be higher on average than in any year in the 20th century, including the 1934 Dust Bowl (Thoma and Shovic 2013).

Historical and projected mean annual temperature for ZION

Above: Projected average annual temperatures exceed the 30-year historical average for Zion National Park for all of the modeled scenarios. Two greenhouse gas emissions scenarios are presented, the low (B1) and high (A2) scenarios (IPCC 2007). Projected climate boxplots indicate the average modeled temperature increase (bold line) and the range of modeled increases (box and whiskers) for fifteen climate models for each time and emission scenario.

Fire-damaged pinyon-juniper woodland

Climate change will manifest itself not only as shifts in mean conditions but also as changes in climate variability (for example, more intense storms, flooding, and drought). Within Zion National Park, these changes may alter the future status, trend, and condition of many resources. Increased winter temperatures lead to a reduced snowpack, reducing spring run-off and soil moisture available to plants. Earlier snowmelt and increased temperatures are predicted to decrease summer streamflows, increasing water temperatures and stress on native fish populations. More frequent drought conditions increase the frequency and severity of wildfires, contributing to conversion of habitat types. Changes in habitat suitability could threaten the persistence of some species while potentially maintaining refugia for other species, including the desert tortoise and an endangered plant, the Shivwits milkvetch (Thoma and Shovic 2013).

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Last Updated: June 19, 2017 Contact Webmaster