On Monday, Environmental Protection Agency (EPA) administrator Scott Pruitt announced that the Obama EPA’s greenhouse gas emission (GHG) standards for model year 2022-2025 cars and light trucks will be reconsidered by the agency. Critics have pointed out that the stringent Obama era CAFE standards, peaking at 54.5 MPG in 2025, are too strict and potentially price millions of Americans out of the market for new cars while also failing to have a meaningful impact on GHG levels.  

Unlike other emissions from motor vehicles, CO2 is not an air contaminant. Yes, it is a greenhouse gas, but so is water vapor. Like oxygen, CO2 is a clear, odorless gas that is a vital component of clean air on Planet Earth.

The auto emissions that chiefly dirty the air are nitrogen oxides (NOX) and various organic compounds, which together form ozone smog in the presence of sunlight, and soot particles from incomplete combustion. Due to advances in emission control technology and fuels, all new cars and trucks today are practically zero-pollution vehicles. That is evident from any number of EPA Web pages posted during previous administrations (see here, here, here, and here).

The U.S. Auto Alliance quantifies this progress to the tenth of a percent. Vehicles produced in 2017 are 99.4 percent cleaner than vehicles manufactured before 1968, and vehicles in 2025 will be cleaner still.

The forthcoming revisions for model years 2022-2025 will at most freeze CO2 and mileage standards at the 2021 level. That would not make vehicles “unclean.” More likely, the CO2/mileage standards will continue to ratchet up. In any event, model year 2022-2025 cars and light trucks will still be subject to EPA’s latest standards for NOX, organic emissions, and particulates, known as Tier 3, which run from 2017-2025. The Tier 3 program is projected to help reduce ambient levels of soot and smog levels through 2030. Nothing the EPA might propose to do will change that.

Obama’s EPA estimated that its entire series of CO2 and mileage CAFE standards from 2012 to 2025 would avert less than two hundredths of a degree Celsius of warming by 2100. Accordingly, no one should worry that Pruitt’s adjustment of the 2022-2025 standards will have any discernible impact on weather patterns or sea level rise.

What the adjustment will do is help avert thousands of dollars ($3,000 per vehicle per the National Automotive Dealers Association) in higher vehicle costs that threaten to price millions of low- and middle-income households out of the market for new vehicles. The EPA’s policy under Pruitt will expand consumer choice, and may also enhance vehicle safety by allowing automakers to build larger, heavier vehicles that provide more protection in collisions.