National parks are the main victims of climate change

The study shows that without action to limit greenhouse gas emissions, many small mammals and plants could be threatened with extinction by the end of the century.

The analysis reveals that over the last century, average temperatures in national parks have increased twice as fast as in the rest of the country, and annual precipitation has declined more in national parks than in the United States. other regions of the country.

At the current rate of emissions, the team predicts that temperatures in the most exposed national parks could increase by 9 degrees Celsius or 16 degrees Fahrenheit by 2100. This rate of change is faster than the migration of many small mammals and plants. disperse "in more hospitable climates.

"Human-caused climate change is already increasing the area burned by fires across the western United States, melting glaciers in Glacier Bay National Park and moving vegetation to Yosemite National Park." "said Patrick Gonzalez, an assistant professor in the Department of the Environment. Science, Policy and Management at the University of Berkeley and lead author of the report of the Intergovernmental Panel on Climate Change (IPCC), a summary of the latest scientific knowledge on climate change .

"The good news is that if we reduce our emissions from cars, power plants, deforestation and other human activities and achieve the goal of the Paris Agreement, we can reduce emissions," he said. Gonzalez.

The locations of these unique ecosystems are what makes them particularly vulnerable to climate change, Gonzalez said. Many national parks are found in deserts, high mountains or in the Arctic region of Alaska, climates known to be the hardest hit by global warming.

"National parks are not a random sample – they are great places and many are in extreme environments," said Gonzalez. "Many are in places intrinsically more exposed to climate change of human origin."

The analysis, which includes the 50 US states, the District of Columbia and four territories of the Caribbean and Pacific, appears on September 24 in the review. Letters of research on the environment.

Mitigation and adaptation

Meteorological stations scattered throughout the United States collected monthly data on temperature and precipitation from 1895. From these data, the researchers created maps of average annual temperatures and precipitation at approximately 800 meters on the ground. most of the United States.

In this study, the team used these maps to calculate historical trends in temperature and precipitation in parks and on landfills. United States together. They found that the temperature in the national parks had risen by just over 1 degree Celsius from 1895 to 2010, about double the warming observed in the rest of the country. Total annual precipitation has decreased by more than 12% in national parks, compared with 3% in the United States. Alaska and its national parks have experienced the most dramatic temperature increases, while precipitation has declined the most in Hawaii.

The team mapped the expected future changes in temperature and precipitation for the climate models representing each of the four climate change scenarios developed by the IPCC. These four "scenarios of the future", as scientists call them, include a scenario where no action has been taken to reduce emissions, one consistent with the Paris Agreement and two intermediaries.

According to the most extreme climate change scenario, the average temperature of all national parks should increase by 5 to 7 degrees Celsius. Keeping to the Paris agreement could limit this rise to between 1 and 3 degrees Celsius. In both scenarios, the temperature could increase the most in Alaska and its national parks, while precipitation could decrease the most in the Virgin Islands and the southwestern United States.

To analyze future projections, the team also "downscaled" climate models, providing more detailed maps of future climate trends in the parks. While the climate models themselves have approximate resolutions of about 100 to 400 kilometers, the reduced data has resolutions of 100 to 800 meters over most of the country.

These maps can assist park staff in planning for future climate change vulnerabilities of endangered and other park resources by developing forest fire protection measures and controlling invasive species.

"The parks department already incorporates this climate change information into their planning and resource management," said Fuyao Wang, associate researcher at the University of Wisconsin-Madison.

"It's important to note that even if we really reduce greenhouse gas emissions, the national park system should experience a temperature change of 2 degrees," said John Williams, a professor of geography at the University of Toronto. Wisconsin-Madison. . "At this point, it's likely glaciers in Glacier National Park will eventually disappear, and what is Glacier National Park if it does not have glaciers anymore?" So, I think that adds importance to the reducing our future climate change levels and also expanding the National Parks Service's mission both to adapt to these changes and to educate us all about these changes. "

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