In a move that officials say will significantly reduce air pollution in coming decades, the Biden Administration announced Mar. 20 the final version of an emissions regulation that will affect all on-road passenger vehicles, including passenger cars, light-duty trucks and medium-duty vehicles. The standard does not apply to heavy-duty trucks or off-road equipment.

The rule, Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles, sets hard targets year-by-year over the next decade for automobile manufacturers, and severely limits the amount of emissions that an automaker’s vehicles can emit. It is a performance-based standard, which the U.S. Environmental Protection Agency says is "technology neutral." The phased-in limit on fossil fuel emissions is intended to spur a greater shift toward hybrid, plug-in hybrid and fully electric vehicles. 

“The standards will slash over 7 billion tons of climate pollution, improve air quality in overburdened communities, and give drivers more clean vehicle choices while saving them money,” said EPA Administrator Michael Regan in a statement. 

According to the EPA, the new model year 2027 standard represents a nearly 50% reduction in average greenhouse gas emissions for light-duty vehicles and a 44% reduction for medium-duty vehicles. It will also lead to a nearly 95% reduction in fine particulate matter, or smog, emissions from gas-powered vehicles.

The rule is a revision of a proposed rule from last year. Compared to the previous version, the final rule adopts several of the requests from automakers and labor unions to stagger the year-by-year targets for emission reductions.

Environmental groups praised the new rule. According to the Natural Resources Defense Council, the transportation sector is the largest source of carbon pollution in the U.S. with cars and trucks contributing more than 80% of those emissions. The nearly 7 billion tons that will be cut between 2027 and 2055 surpasses the total greenhouse gas emissions of the U.S. in one year, NRDC said.