Clean Air Act

Los Angeles used to be one of the most polluted cities on the planet. After decades of improvements, pollution levels are ticking up again.

President Trump mentioned clean air, emissions, and the Green New Deal, but failed to bring up climate change at his environmental event Monday.

A new book chronicles the rise of extreme air pollution—and the fixes that are helping to clean up the atmosphere

California's cities have long been plagued by smog, but now some of the state's cleanest air is being polluted by smoke from climate change-fueled wildfires.

Some state legislators seem to agree that California's standards are what's in the United States' best interest.

The plan would end efforts to make cars and trucks average more than 50 miles per gallon by 2025.

The coalition of attorneys general argue the Trump administration has failed to fulfill its legal obligation to control methane emissions.

The effect of lax federal fuel standards on the climate fight depends largely on the fate of the California waiver.

New research finds air pollution levels are higher in states with Republican governors.

A new study tells us how we can have both.

Researchers argue that reducing fine particulate matter from forest fires, cars, and coal-fueled power plants is worth it, even if the levels are already low.

Wildfires may be harming the health of people who live hundreds or thousands of miles from the flames.

Dear coal industry, stop reminiscing over outdated power plants. They’re holding you—and us—back.

A sweeping new law could make data like photographs and soil samples inadmissible in court.