President Trump announced on Monday that he planned to relax limits on pollution from cars, saying that the move wouldn’t “mean a damn bit of difference to the environment.”
But decades of science show that the pollution from automobile tailpipes has harmed the environment and public health, from the days when leaded gasoline sent neurotoxins into the air and soil to the carbon dioxide emissions that are heating the planet right now.
Transportation is the largest source of greenhouse gas emissions in the United States.
It accounts for about a third of all U.S. emissions contributing to climate change, which is leading to more frequent and intense extreme weather like deadly heat waves, droughts, floods, and storms.
The Biden administration tightened limits on pollution from tailpipes as a way of pressuring automakers to sell more electric vehicles, which do not emit carbon dioxide. It required automakers to achieve fuel economy standards of an average of 65 miles per gallon for all the car models they sell by 2031.
Mr. Trump said he intended to go back to the fuel economy standards in place in 2020 during his first administration, when automakers were required to achieve a fleetwide average of about 40 miles a gallon.
“It doesn’t mean a damn bit of difference, either, for the environment,” Mr. Trump said on Monday in the Oval Office. “It doesn’t matter.”
“They’re making it impossible for people to build cars,” he added.
Vehicles produce other pollution, too, which is bad for human health.
In addition to releasing the carbon dioxide that is driving climate change, cars and trucks also emit pollutants like nitrogen oxide, carbon monoxide, volatile organic compounds and particulate matter.
George D. Thurston, a professor of environmental medicine at NYU Langone Health, a leading hospital system in Manhattan that includes a medical school, said fossil fuel pollution from combustion engine vehicles was “insidious.” Breathing fine particles from sources like vehicles can causes inflammation that spreads throughout the body, increasing increase the risk of health problems like lung cancer, heart disease and asthma.
“When you’re looking at the various source of pollution, it’s the car in front of you, it’s the truck in front of you, it’s the roads you walk along,” Dr. Thurston said.
“It causes impacts that we all experience every day of our lives,” he said, adding, “I think the president, like most of us, is unaware of this.”
Brenda Ekwurzel, a climate researcher with the Union of Concerned Scientists, said the two areas where vehicle tailpipe pollution have the most direct effects on the environment are public health and the warming of the planet.
“We lose peoples lives every day because of vehicle emissions,” she said.
Starting in the 1920s, lead had been blended with gasoline, sending the neurotoxin into the air and soil and endangering human health, particularly for children. Leaded gasoline was banned in the United States for road vehicles in 1996.
Auto rules have reduced emissions.
The Environmental Protection Agency calculated that the Biden administration’s auto rule would eliminate 7.2 billion metric tons of carbon dioxide over the life of the regulation. That’s the environmental equivalent of taking 1.6 million cars off the road.
The Biden rules would have also prevented 8,700 tons of particulate matter; 36,000 tons of nitrogen oxides; and 150,000 tons of volatile organic compounds, according to E.P.A. estimates.
The agency calculated that the rule could cost the automobile industry about $40 billion annually.
It pegged the health benefits in the range of $99 billion annually because of improved air quality. That, in turn, would lead to fewer premature deaths as well as a reduction in hospital admissions for respiratory and cardiovascular illnesses, nonfatal heart attacks, aggravated asthma and decreased lung function, the agency said.