The US national park service is home to 417 protected areas, showcasing some of the country’s most beautiful sites, like sandstone formations in Arches National Park, the lush rainforests of Olympic National Park, and the towering granite walls in Yosemite. The parks preserve delicate, unique ecosystems, and the natural resources they harbor.
But as climate change progresses, it appears that national parks are particularly vulnerable. Over the last 100 or so years, the average temperature in national parks has increased at double the rate of the rest of the US. Rain and snowfall have also decreased at a faster rate than the rest of the US.
According to a new analysis, that trend is set to continue (pdf): In the best-case scenario, more than half of national park land could experience warming of more than 2°C (3.6°F). In the worst, temperatures could increase a whopping 9°C (16°F).
The study, published this week in Environmental Research Letters, is the first to examine climate-change trends over all 417 national parks. In their analysis, climate scientists modeled how temperature and precipitation would change over the next century according to four scenarios. The worst-case scenario is one in which society does nothing to address climate change; the best-case assumes we’ve implemented the terms of the Paris agreement, and global temperatures still rise, but less dramatically. The other two scenarios fall somewhere in between the two. (The way things are going currently, we’re closer to the worst-case scenario than the best, by the way.)
Warmer, drier national parks could spell danger for the communities that rely on their resources. Lead author Patrick Gonzalez, an ecologist at the University of California-Berkeley, gives the example of Hetch Hetchy Reservoir in Yosemite National Park, which provides drinking water to San Francisco. Reduced snowfall would mean less water in the reservoir, and warmer temperatures may lead to a series of cascading effects: Warmer weather allows bark beetles to thrive, which in turn kill trees, causing soil erosion that reduces the quality of the reservoir’s water.
Having this data on hand could help natural-resource managers identify the most vulnerable areas and create conservation plans for at-risk plants and animals. But, of course, the best-case scenario would be that we collectively make an effort to decrease emissions. Many national parks, for instance, are adding solar power to their grid or public-transit systems for visitors.
“Cutting carbon pollution from cars, power plants, and other human sources can save parks from the most extreme heat,” Gonzalez says. “Preventing damage is more effective and less costly than cleaning up the damage.”