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In 1916, Congress created the National Park Service to conserve “the scenery and the natural and historic objects and the wild life therein” for the “unimpaired enjoyment” of current and future generations. But in an era of climate change, keeping these sites unimpaired is no longer possible. Whether it’s the disappearance of Glacier National Park’s namesake glaciers or Joshua Tree National Park’s namesake trees, the unique habitats we set aside for special protections are changing or vanishing as global temperatures climb.

What’s more, new research suggests that national parks have been more vulnerable to warming than the rest of the country—and they could look drastically different by 2100. Even so, they remain our best bet for protecting wildlife, including birds, as species adapt to the changing environment or move elsewhere.

The new study, in Environmental Research Letters, looked at the entire national park area— including parks, monuments, preserves, battlefields, historic sites, seashores, lakeshores, and more—and found that human-caused climate change has exposed our national parks to hotter, drier conditions compared to the United States as a whole. Between 1895 and 2010, the average annual temperature of the entire park area rose twice as fast as the United States overall. It also received 12 percent less rainfall, compared to 3 percent less rainfall across the rest of the country.

Parks are experiencing such disproportionate impacts because a large portion of them protect places highly affected by climate change. For instance, a full 63 percent of the entire national park area is in Alaska, which is heating up more rapidly as its reflective snow cover melts. (For comparison, Alaska’s area comprises only 16 percent of the United States as a whole). In a similar vein, the average elevation of the national park area is nearly 1,000 feet higher than the rest of the country (3,215 feet versus 2,395 feet above sea level); the atmosphere is thinner at higher elevations and warms more quickly.

Moving into the future, the national park system as a whole is projected to become hotter by roughly 3°F to 10°F (2°C to 6°C) by 2100. Even if we manage to keep the planet’s temperature from rising more than 1.5°C, as a new report from the Intergovernmental Panel on Climate Change urges, 58 percent of national park areas could still heat up by more than 2°C (3.6°F) this century.

Despite these significant changes, national parks still remain the best refuges for birds, says Joanna Wu, a biologist at the Լ����Ƶ who was not involved in the new research. “Our studies show that more birds are expected to enter into national parks [in the future] than leave them.”

Earlier this year, Wu published work that projected into 2070. She found that because of climate change, the average species turnover rate in 274 park sites could be as high as 23 percent across both summer and winter. "The birds that we think belong to a certain park might be completely different by mid-century," she says.

Like the new research, Wu’s study found that most species movement in and out of parks will likely occur at higher latitudes and higher elevations. Maine’s Acadia National Park, the summer home for many warbler species, could become too hot, Wu says. "If climate conditions keep getting warmer, those birds might get pushed farther north.” Meanwhile, Denali National Park and Preserve in Alaska could see an influx of as many as 40 new bird species as it grows warmer.

These are big changes not only for parks, but also for park managers. For a century, they’ve managed park resources to leave them “unimpaired” for future generations—an effort that is no longer possible. So, they have to change their tack. “Our research provides the data now to help manage parks for potential future conditions rather than make them look like a past to which we can no longer return,” says Patrick Gonzalez, lead author on the paper and a climate scientist speaking under his academic affiliation with the University of California, Berkeley. Gonzalez is also a climate change scientist with the National Park Service (NPS).

Jonathan Jarvis, who was NPS director under President Obama, thinks a lot about parks’ future as the climate changes. Back then, he introduced the idea of resource management “for continuous change that is not yet fully understood” to biologists and conservationists throughout NPS. The initial stages include leading more scientific research, bolstering infrastructure against floods, and looking for migration routes outside of park borders to help species migrate from park to park.

The work of imagining and implementing forward-thinking management is only just beginning. But Alaska’s accelerated warming means we already have some understanding of what wildlife might encounter in the coming decades. A steep temperature rise could result in thermokarsting, which occurs when and forms hollows in the ground, says Jarvis, who is now executive director of the Institute for Parks, People, and Biodiversity at the University of California, Berkeley. “You get swampy, muddy melt areas that keep growing and break down hard surface infrastructure used by wildlife, residents, and native people for traveling.” Melting permafrost not only becomes a migration obstacle for animals, but it releases carbon dioxide previously trapped in the ground into the atmosphere.

Once Alaska begins to warm significantly, vegetation, food availability, and how animals respond to seasonal shifts will change, too, Jarvis says. “If the climate is no longer aligned with the seasonality of the Earth, that’s all thrown into flux.”

Figuring out how to best help wildlife under these rapidly changing conditions is conservationists’ project of the century. It will take careful forethought and planning, and loads more research. This new study at least helps point managers in the right direction.

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