The busiest travel day of the year brings a renewed focus on transportation, and for the first time since the 1970s, U.S. carbon dioxide emissions from transportation have eclipsed emissions from electricity generation as the top source of greenhouse gases.
The change comes as U.S. electricity generation relies less on coal and more on renewables and natural gas (a less carbon-intensive fossil fuel). Transportation emissions have also declined from a peak in 2008 due to steadily improving fuel economies, although there has been a small uptick recently as a result of a drop in gas prices. The projected growth in electric vehicles suggests decreases in CO2 transportation emissions are on the horizon. Even when accounting for how electricity is generated, an electric vehicle emits less carbon dioxide than a comparable gasoline car in a majority of U.S. states. More