Attorneys general from 15 states filed a legal challenge on Tuesday over the Trump administration’s delay of Obama-era rules reducing emissions of smog-causing air pollutants."

"The biggest gas storage facility in the West resumed operations Monday, nearly two years after a blowout led to the nation’s largest-known methane release and drove thousands of families from their Los Angeles homes."

"Environmental groups that say they’re seeking to restore clean air standards for vehicles on the nation’s highways have sued the federal government in New York."

"A federal court told the Environmental Protection Agency (EPA) Monday that it has to enforce an Obama administration methane pollution rule."

"The only way to know exactly what’s in a wildfire’s smoke is to sample straight from the haze. So during the Rim Fire in Yosemite—which emitted so much smoke it formed its own clouds—a NASA DC-8 passenger plane and an Alpha fighter jet each crisscrossed through the plume. On both planes, scientists had created an in-flight lab to measure exactly what the fire was producing."

"During a stop in East Chicago three months ago, Scott Pruitt vowed that cleaning up the low-income, predominantly African-American and Latino city would be one of his top priorities as head of the U.S. Environmental Protection Agency."

"The Hogan administration notified the federal Environmental Protection Agency on Thursday that it plans to file a lawsuit alleging the agency has failed to act against states whose smokestack emissions pollute Maryland’s air."

"The Trump administration has erased an Obama-era requirement that Harley-Davidson Motor Co. spend $3 million on a pollution control project as part of its penalty for cheating on air emissions."

"Green groups sued the U.S. Environmental Protection Agency on Thursday to force Texas to toughen its stance on air pollution by using stricter language in permits it issues to oil refineries and power plants."