Climate has national parks heating up, drying out faster than the rest of U.S.

photo of denali national park
The biggest increase in mean annual temperature was in Denali National Preserve in central Alaska: a whopping 4.3° C (7.7° F).

The landscapes that comprise America’s national park system are experiencing climate change with a special intensity — warming about twice as fast as the country overall, while experiencing a fourfold greater precipitation decline.

These trends, according to a paper just published in the journal Environmental Health Letters, point to rising pressures, even potential extinction, for plants and animals the parks were established in part to conserve. Not to mention the potential loss of such namesake features as the ice sheets of Glacier, or the huge, extraterrestrial-looking yuccas of Joshua Tree.

Climate change may also necessitate a rapid, expensive shift in management approach to head off certain impacts — an undertaking that, even if it overcame resistance from the Trump White House, would likely tee up a big fight over whether to mitigate this human impact or just “let nature take its course.”

The new paper is hardly the first to discuss impacts that global warming and its corollary changes will bring to these treasured places; for one recent and rather close-to-home example, we have the discussion of the ecological future of Isle Royale, with or without wolves.

But, somewhat amazingly, it is “the first spatial analysis of historical and projected temperature and precipitation across all 417 U.S. national parks.” (That big number includes national monuments, historical sites, preserves, etc., in addition to the 60 full-fledged “national parks”; in all, the properties make up about 4 percent of U.S. land area.)

Stunning, vulnerable locations

The main driver of these differentially larger trends is location, national parklands being disproportionately situated in areas where climate impacts tend to appear first and worst, like alpine reaches of mountain ranges, appealing southwestern deserts and, especially, latitudes of the high north (almost two-thirds of the system’s total acreage is in Alaska, the report notes).

But, of course, this is why the places were selected for park status: to preserve their remote and dramatic landscapes, which stand in stirring contrast to the kinds of places most people choose to settle, along with the unique biological, cultural and historical resources they contain.

The principal author of the paper is Patrick Gonzalez, who is the National Park Service’s top climate expert and also teaches environmental science at the University of California-Berkeley; it is a sad sign of the times that in discussing the results with, say, the Guardian, he is careful to say he is speaking in his professorial role, not from his federal position.

For this work, researchers took monthly temperature and precipitation data gathered by U.S. weather stations from 1895 to 2010 and laid it over maps of the entire U.S. plus four territories. They drew in park boundaries and analyzed differences between park and nonpark lands as a whole, and also within six geographic domains: the contiguous 48 states, Alaska, Hawaii, Guam, American Samoa, and Puerto Rico/Virgin Islands.

Key results:

  • The mean annual temperature of the park lands went up about 1.0° Celsius (1.8° F.), which is double the rate for the U.S. overall. The increases appeared in all six domains, and affected 63 percent of land area in the parks, compared to 42 percent of the U.S. as a whole; the biggest increase by far was in Denali National Preserve in central Alaska: a whopping 4.3° C (7.7° F).
  • Annual precipitation has generally increased across the United States since 1895, but about 3 percent of the country has seen decreases. In the parks territory, declines affected 12 percent of the land area, or a portion four times larger. Biggest drop: Hawaii’s Honouliuli National Monument, at 85 percent.
  • Significant physical and ecological changes traceable to climate change have already been detected in some parks; in addition to the previously mentioned impacts at Glacier and Joshua Tree, examples include Yellowstone’s losing trees to bark-beetle infestations at unusually high rates, marked vegetation shifts in Yosemite, and worsening wildfire patterns in many places.
  • “Climate velocity,” in this case the pace of shifts to warmer and drier regimes, is the main factor in whether plants and animals have time to adapt by relocating their ranges; the new evidence indicates that the rates of change may well exceed the “dispersal capabilities” of many trees, herbaceous plants and small animals.

Looking to the future, the paper offers these grim conclusions:

Only under a scenario of substantial emissions reductions [worldwide] would much of the national park area be located in areas of <2.0° C [3.6° F] increase by 2100, the upper limit of the Paris Agreement goal.

The possibility of future climate states in North America with no current analog, particularly in the Arctic and the southeastern and southwestern U.S., exacerbates the vulnerability of restricted-range endemic species to extinction.

And what if emissions trends continue at the upper end of current scenarios, as frankly seems more likely than a sharp and sustained reduction? Writing in The Conversation, Gonzalez says,

This could increase temperatures in national parks up to 9 degrees Celsius [16.2° F] by 2100, with the most extreme increases in Alaska, and reduce precipitation by as much as 28 percent, in the national parks of the U.S. Virgin Islands. Heating could outpace the ability of many plant and animal species to move and stay in suitable climate spaces.

What can the managers do?

So, what are the chances that the National Park Service will accelerate its response to climate trends in its management planning? Here are a few discouraging excerpts from a recent piece by Elizabeth Shogren, carried by Grist and other climate-minded publications, about the same kinds of issues playing out in a park that lacks the iconic stature of a Glacier or a Yellowstone:

Park officials scrubbed all mentions of climate change from a key planning document for a New England national park after they were warned to avoid “sensitive language that may raise eyebrows” with the Trump administration.

The superintendent of the New Bedford Whaling National Historical Park in Massachusetts had signed off a year ago on a 50-page document that outlines the park’s importance to American history and its future challenges. But then the National Park Service’s regional office sent an email in January suggesting edits: References to climate change and its increasing role in threats to the famous whaling port, such as flooding, were noted in the draft, then omitted from the final report, signed in June.

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The New Bedford park was created by Congress in 1996 to preserve 13 city blocks of a Massachusetts seaport that was home to the world’s largest whaling fleet in the 19th century. The park tells the broader history of American whaling.

Flooding from rising seas, increased snow melt and stormwater, larger storm surges and extreme heatwaves are among the threats from human-caused climate change to the park’s historic structures. A 1960s hurricane barrier that protects New Bedford is vulnerable to widespread failure in a 100-year storm if sea levels rise by 4 feet. A Category 3 hurricane could breach the barrier at current sea levels.

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Earlier this year, Reveal exposed an effort by park service managers to remove references to human-induced climate change in a scientific report about sea-level rise and storm surge at 118 national parks. The Guardian recently reported on the Trump administration’s efforts to stall funding for climate change research in the Interior Department by subjecting research projects to unprecedented political review by an appointee who has no scientific qualifications.

In a survey by the Union of Concerned Scientists, government scientists reported being asked to stop working on climate change and connecting their science to industry actions. These are just a few of the examples of science under siege compiled by Columbia University in its “silencing science” tracker.

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The full paper, “Disproportionate magnitude of climate change in United States parks,” can be read here without charge.

Comments (1)

  1. Submitted by Ray Schoch on 09/28/2018 - 10:32 am.

    “Science under siege” seems an apt phrase. Denial, denial, denial, appears to be the default response by the powers-that-be to this sort of bad news.

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