Transportation is the largest source of greenhouse gas emissions in the United States, accounting for approximately 28% of the nation's total emissions. Globally, the sector contributes about 15% of emissions, encompassing vehicles such as cars, trucks, planes, ships, and trains.
The primary source of transportation-related emissions is the combustion of fossil fuels, which releases significant amounts of carbon dioxide (CO₂) and other greenhouse gases into the atmosphere. These emissions contribute to global warming, leading to rising temperatures, extreme weather events, and deteriorating air quality.
Through the Biden administration there have been notable advancements in sustainable transportation technologies. Some notable examples are:
The Trump administration has been less supportive of clean transportation ambitions.
For example, already in February, 2025, the Department of Transportation (DOT) announced plans to rescind various policies established during previous administrations. This broad directive could affect emissions standards, fuel efficiency requirements, and funding for climate-focused transportation initiatives. If fuel economy and vehicle emissions standards are loosened, automakers may slow the transition to cleaner technologies, prolonging reliance on fossil fuels and increasing CO₂.
The administration’s expected rollback of environmental regulations in the commercial transportation sector will likely weaken emissions restrictions for freight trucking and shipping. Deregulation could allow more diesel-powered heavy-duty vehicles to remain on the roads longer, delaying the transition to cleaner alternatives like electric or hydrogen-powered trucks. If the EPA’s proposal (July, 2025) to rescind the endangerment finding goes through, it would effectively repeal all GHG emissions regulations under the agency, and industries, including automakers, would no longer be required to report or track their emissions.
The Trump administration has specifically targeted electric vehicles, vowing on the first day to terminate all “electric vehicle mandates” and subsidies for EVs claiming this won’t “mean a damn bit of difference to the environment.” Tax credits for EV purchases and leases were terminated as of the end of September 2025. Freezing funding from the Inflation Reduction Act and Infrastructure Investment and Jobs Act, including the National Electric Vehicle Infrastructure program (which, however, has survived), and repealing California’s leading vehicle emissions standards are some of the other Trump administration’s actions which aim to harm the electric vehicle industry and cause the U.S. to fall even further behind in this growing global market.
The potential weakening of emissions standards and reduced support for sustainable transit alternatives could slow the U.S.’s progress toward a lower-carbon transportation sector—at a time when global climate goals demand acceleration, not retreat.
CREDIT: EPA
