Transportation CO2 emissions in the U.S. 2018-2020, by month

The outbreak of COVID-19 in early 2020 led to lockdowns being imposed around the world, resulting in a dramatic decline in travel. In 2018 and 2019, monthly transportation-related emissions in the U.S. followed a similar pattern, but considerable reductions occurred in 2020. By March 2020, emissions had fallen to 137.9 million metric tons, and by April had dropped even further to 105.2 million metric tons. This was a reduction of more than 30 percent compared to emissions levels recorded in the same month in 2019. As lockdowns and restrictions eased in the following months, emissions began to increase, rising to 144 million metric tons by July 2020. However, monthly emissions remained below pre-pandemic levels for the the rest of the year. Total transportation emissions in the U.S. plummeted 15 percent in 2020 compared to 2019 levels.