Why We Need to Decarbonize Transportation

Understanding and addressing climate change is critical to EPA's mission of protecting human health and the environment. In order to reduce the potential impacts of climate change, the United States has established the goal of a net-zero greenhouse gas (GHG) economy by 2050 (pdf) (3.5 MB, November 2021). Transportation is the largest source of greenhouse gas (GHG) emissions in the U.S and, as such, any plan to achieve a net-zero GHG economy must reduce transportation GHG emissions to near zero. This process of reducing GHG emissions is also referred to as decarbonization, since carbon dioxide makes up the majority (97%) of greenhouse gases emitted by transportation activities.

The transportation sector—which includes all modes of travel through land, air, and sea to move people and goods—accounts for nearly a third of all domestic GHG emissions.¹

In 2017, transportation surpassed the electric power sector to become the largest direct source of U.S. GHG emissions. Transportation emissions increased 22% between 1990 and 2019, largely due to increased vehicle miles traveled. After a reduction in transportation emissions during the COVID-19 pandemic, transportation demand has returned to near pre pandemic levels and is projected to continue growing.²

To address the growing climate crisis, and to meet the goal of net-zero GHG emissions economy-wide, we must eliminate nearly all greenhouse gas (GHG) emissions from the sector by 2050 and implement a holistic strategy to achieve a future mobility system that is clean, safe, secure, accessible, affordable, and equitable, and provides sustainable transportation options for people and goods. The U.S. National Blueprint for Transportation Decarbonization (Blueprint) is the roadmap for how we can address these issues to provide better transportation options, expand affordable and accessible options to improve efficiency, and transition to zero-emission vehicles and fuels.

For more information on emissions by sector, visit Fast Facts on Transportation Greenhouse Gas Emissions, or for even more details - Fast Facts U.S. Transportation Sector Greenhouse Gas Emissions 1990 –2020 (pdf) (360 K, May 2022, EPA-420-F-22-018).

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¹ Total 2019 U.S. GHG emissions with transportation and mobile sources breakdown. Data derived from the EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks. This Blueprint uses 2019 as a baseline since impacts due to COVID-19 complicate the use of later data.

²Moving 12-Month Total Vehicle Miles of Travel on All Roads, January 1998 to March 2022. U.S. Department of Transportation, Federal Highway Administration; and COVID-19 Related Transportation Statistics