Green Cities

Carbon Pollution, Climate Policy, and the Built Environment: Transportation

As part of the Carbon Pollution, Climate Policy, and the Built Environment blog series, this entry focuses on the U.S. transportation sector, the second largest source of greenhouse gas (GHG) emissions in the U.S. In 2011, 28% of the total U.S. GHG emissions came from transportation, primarily from carbon dioxide emissions from fuel combustion in motor engines. GHG emissions from transportation increased 19% between 1990 and 2010. A national inventory report suggests that the emissions increase from this sector was due primarily to the increase in the amount of vehicle miles traveled (VMT) over this period. The EPA suggests that much of the increase is the result of outward growth of cities and towns and the roads built to serve the new development. Development has become more dispersed since the 1950s, resulting in the increased distances between destinations. At the same time, the design of communities has changed to accommodate more cars. The combination of these two changes has made it impractical or impossible for many people to get around without a car, further encouraging community designs that preclude other choices. While the population roughly doubled between 1950 and 2011, vehicle travel increased nearly six-fold during the same period.

In his recent climate action plan, President Obama made a commitment to building a climate change-defiant, 21st century transportation sector by increasing fuel economy standards and supporting advanced transportation technologies. He promised to do so by investing in research and development for advanced fuel technology, such as biofuels and clean energy. He also promised to continue to leverage partnerships between private and public sectors to help deploy the new technologies. The Obama administration already finalized the first-ever fuel economy standards for heavy-duty trucks, buses, and vans in 2011, and another one for cars and light-duty trucks the following year. In total, the new standards are projected to save consumers more than $1.7 trillion at the gas pumps. They will also reduce U.S. oil consumption by 12 billion barrels. The new plan clearly acknowledges the need to green the transportation sector in order to address climate change. While regulating fuel emissions standards is a step in the right direction, a comprehensive plan to create a sustainable transportation infrastructure must also emphasize its design, connectivity, and accessibility. In the recent report, Our Built and Natural Environments, the EPA emphasizes that where and how we build the built environment has a surprising degree of impact on people’s traveling behavior. The report also details suggestions for infrastructure design strategies and different types of developments. Next week, we will go into more detail about these findings and suggestions. – Written by Jiin G. Park **Jiin G. Park is an intern at Earth Day Network and a MA candidate in Environmental Conservation Education at New York University, 2014.