Disproportionate magnitude of climate change in United States national parks

Abstract

Anthropogenic climate change is altering ecological and human systems globally, including in United States (US) national parks, which conserve unique biodiversity and resources. Yet, the magnitude and spatial patterns of climate change across all the parks have been unknown. Here, in the first spatial analysis of historical and projected temperature and precipitation across all 417 US national parks, we show that climate change exposes the national park area more than the US as a whole. This occurs because extensive parts of the national park area are in the Arctic, at high elevations, or in the arid southwestern US. Between 1895 and 2010, mean annual temperature of the national park area increased 1.0°C±0.2°C century −1 (mean±standard error), double the US rate. Temperature has increased most in Alaska and its extensive national parks. Annual precipitation of the national park area declined significantly on 12% of national park area, compared to 3% of the US. Higher temperatures due to climate change have coincided with low precipitation in the southwestern US, intensifying droughts in the region. Physical and ecological changes have been detected and attributed mainly to anthropogenic climate change in areas of significant temperature increases in US national parks. From 2000 to 2100, under the highest emissions scenario (representative concentration pathway [RCP] 8.5), park temperatures would increase 3°C-9°C, with climate velocities outpacing dispersal capabilities of many plant and animal species. Even under the scenario of reduced emissions (RCP2.6), temperature increases could exceed 2°C for 58% of national park area, compared to 22% of the US. Nevertheless, greenhouse gas emissions reductions could reduce projected temperature increases in national parks by one-half to two-thirds.

Repeatable approaches to work with scientific uncertainty and advance climate change adaptation in US national parks

“…The US National Park Service (NPS) began addressing climate change as early as the 1990s, and in 2010 NPS Director Jonathan Jarvis stated that "climate change is fundamentally the greatest threat to the integrity of our national parks that we have ever experienced" (NPS 2010). Today, parks throughout the NPS system experience impacts of human-caused climate change (e.g., Monahan and Fisichelli 2014;Gonzalez 2018) that threaten iconic park resources. Climate-related impacts include: melting glaciers (e.g., Glacier National Park, Kenai Fjords National Park; Burgess et al 2013); thermokarst formation effects on archaeological sites (Gates of the Arctic National Park and Preserve; Gaglioti et al 2016); loss of Joshua trees (e.g., Joshua Tree National Park; Sweet et al 2019); and sea-level rise threatening historic lighthouses (e.g., Cape Hatteras National Seashore; Schupp et al 2015), historic artifacts (Anderson et al 2017), and seaside forts (e.g., Dry Tortugas National Park; Schupp et al 2015).…”

Congruence between future distribution models and empirical data for an iconic species at Joshua Tree National Park

“…Notable and striking declines in bird communities, attributed to climate change, are already evident in the Mojave Desert (Iknayan and Beissinger 2018). Within this region of the United States, the National Park System has set aside examples of wilderness and biodiversity, protecting a natural heritage of global significance; climate change threatens these natural riches, especially for those parks in the arctic and desert regions (Gonzalez et al 2018). This outlook for U.S. desert national parks is dire; however, while it is impossible for park managers to tackle the primary sources of climate change directly, if managers can identify, verify, and protect features that buffer against the effects of a warming and drier climate, there might be a somewhat more optimistic future (Gonzalez et al 2018).…”

Den‐site characteristics and selection by brown bears (Ursus arctos) in the central Brooks Range of Alaska

“…Other studies have documented the importance of snow load for bear dens (Vroom et al 1980, McLoughlin et al 2002, Liston et al 2016, Smereka et al 2017; however, the importance of snow load likely decreases in warmer environments (Schoen et al 1987) and/or in areas of greater snowfall where the benefits from snow depth only extend to a point once a critical snow depth is attained (Pigeon et al 2014). The Arctic is warming approximately twice as fast as the rest of the planet (Holland and Bitz 2003, Comiso and Hall 2014, Gonzalez et al 2018. Warming winter temperatures may help melt snow and decrease the insulative snowpack for denning bears or, alternatively, warmer temperatures could increase snowfall, thus increasing the snowpack (Stafford et al 2000, Hartmann andWendler 2005).…”