California's National Parks in Peril

Human-caused climate disruption could make Yosemite National Park hotter this century than Sacramento has been, according to a new report from RMCO and the Natural Resources Defense Council (NRDC).

The report includes new local climate projections for ten national parks in California. If future emissions of heat-trapping pollutants are what the California Climate Change Center calls “medium-high,” the average of the projections from the six climate models is for Yosemite National Park to get 7.5°F hotter by 2070-2099 than it was in 1961-1990. To put that in perspective, that would be enough to make Yosemite 0.3° hotter than Sacramento historically has been. Similarly, Sequoia and Kings Canyon national parks would become hotter than the Sonoma County coast. Point Reyes would become as hot as Santa Barbara has been.

Climate projections for all ten of the national parks are summarized in the table below. As detailed in the report, lower levels of future pollution would lead to smaller temperature increases.

Higher temperatures would drive widespread changes in the national parks. Also threatened would be a significant contribution to California’s economy. National parks in the state draw over 34 million visitors a year. Their spending contributes $1.24 billion to the state’s economy and supports over 19,000 jobs.

A news release on the report is here.

The full report is here (it is 18.5 MB, which is a large file!). Or it can be downloaded in parts, each under 5MB in size: part 1, part 2, part 3, and part 4. A four-page summary is here.

Among a broad range of threats to the ten national parks identified in the report are:

• Joshua trees, which need winter freezes to set seeds, are projected to disappear entirely from the national park named after them, and from most of Death Valley National Park and Mojave National Preserve.
• In Redwood National Park and Muir Woods National Monument, higher temperatures already have reduced by 30 percent the coastal fog that redwoods depend on for nearly half their water their water supply. A continued decrease in the fog could keep the coast redwoods from growing to the astonishing heights that make them the world’s tallest trees.
• In Sequoia, Kings Canyon, and Yosemite, giant sequoias in the mountains parks may not be resilient to the water stress and increased wildfire expected with rapid climate change.

Mori Point, Golden Gate National Recreation Area
National Park Service photo

• Yosemite Falls, mostly fed by snowmelt, could dry up more often and earlier in summers, depriving many park visitors of one of the world’s greatest sights.
• In Yosemite, Sequoia, and Kings Canyon, as the parks have gotten hotter and drier, pine and fir trees are dying more quickly. The death rate of trees has nearly doubled over just the past two decades.
• Sea-level rise of 2.0 to 4.7 feet in this century, as projected by the California Climate Change Center, would lead to seas washing over in storms and then permanently inundating low-lying areas in Point Reyes National Seashore, Golden Gate National Recreation Area, and Redwood National Park. At risk are beaches, wetlands, other wildlife habitat, historic structures, highways and roads, campgrounds, picnic areas, and a visitor center.
• In Yosemite, mammals already are moving upslope to stay ahead of rising temperatures. About half of small mammal species in Yosemite now live at elevations different from where they were found nearly a century ago. Most have moved to higher elevations, by an average of about 500 yards. Along the coast, seals and shorebirds could lose habitat to a higher sea, and many may abandon the coastal national parks as suitable areas disappear.

To keep these national parks the special places that Americans know and love will take actions to reduce heat-trapping pollutants. Those actions can prevent the worst effects on the parks, and also save people energy costs and create clean-energy jobs.

A technical fact sheet on these climate projections is available here.