Report Aug 12, 2025

Driving Dirty Air: How U.S. Vehicle Pollution Harms Our National Parks

America’s national parks are beloved for their extraordinary landscapes and rich cultural and historical significance. Visitors to our parks expect them to have clean air and healthy ecosystems, befitting their status as some of the nation’s most treasured places. The reality, however, is that our national parks are frequently harmed by air pollution and a rapidly warming planet.

60%
of all national park units are located in counties with high levels of on-road vehicle air pollution.

Vehicles like cars and trucks play a major role in air quality and climate challenges in our parks, but, until now, their pollution contributions have been less understood compared to other sources of pollution. Our report, Driving Dirty Air (PDF), identifies how vehicle pollution from across the nation — particularly from urban areas (identified in the report as “hot spot areas”) — is contributing to air and climate pollution problems in our national parks.

From Los Angeles to New York City and the Everglades to Rocky Mountain National Parks, vehicles are emitting emissions equivalent to hundreds of coal plant units (many coal plants have more than one unit). Read our report (PDF) for more information, understand what solutions exist to provide cleaner air and a healthier climate for our parks and get involved to help us protect America’s national parks!

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