Battery-electric vehicles, plug-in hybrids, and hydrogen fuel-cell vehicles already produce lower overall emissions than the average gasoline small SUV, and have a pathway to further reducing emissions, according to a recent Department of Energy report.

The report considered the well-to-wheels and cradle-to-grave emissions of all propulsion types. Well-to-wheels includes all emissions associated with a particular energy source, allowing for an apples-to-apples comparison between fossil fuels, hydrogen, and electricity. Cradle-to-grave estimates also factor in emissions from vehicle manufacturing.

2021 Volkswagen ID.4 Pro S

2021 Volkswagen ID.4 Pro S

According to the report, a 2020 battery-electric vehicle with 300 miles of real-world range using the average United States grid mix produced 206 grams of carbon dioxide (CO2) per mile. That's about half the 402 grams of CO2 per mile emitted by the average gasoline small SUV. Assuming vehicles meet Energy Department performance targets, that's estimated to drop to 43 grams of CO2 per mile by 2050.

A 2020 plug-in hybrid using the same grid mix emitted an average 250 grams of CO2 per mile, according to the report—still substantially better than a conventional gasoline SUV.

A 2020 fuel-cell vehicle using hydrogen produced from natural gas was rated at 237 grams of CO2 per mile. That improved to 167 grams per mile with a 40% mix of renewable hydrogen, and 117 grams per mile with hydrogen produced from landfill gas.

2021 Toyota Mirai

2021 Toyota Mirai

The use of a small gasoline SUV as the benchmark for internal-combustion reflects the popularity of these vehicles, which are beginning to displace sedans and hatchbacks. That's causing an emissions increase in the short term.

A 2019 report named SUVs as the second-largest contributor to global CO2 increases this decade (behind the energy sector), while another blamed SUVs for increasing overall European emissions despite tougher standards. A report released earlier this year found that emissions reductions from EVs in 2020 were cancelled out by SUVs.

The Energy Department report reinforced the conclusion of the Union of Concerned Scientists, which has constructed an online tool showing the well-to-wheels emissions of new cars sold in the United States. The data show that, given typical driving patterns, there isn't a single gasoline vehicle you can buy today that, on a national basis, promises to be cleaner than an all-electric one.