The U.S. Environmental Protection Agency (EPA) released its 19th annual report of overall greenhouse gas (GHG) emissions, which show a 3.4 percent decrease in 2012 from 2011.
The Inventory of U.S. Greenhouse Gas Emissions and Sinks, which is submitted annually to the Secretariat of the United Nations Framework Convention on Climate Change, presents a national-level overview of annual greenhouse gas emissions since 1990.
The major contributors to the decrease in emissions from 2011-2012 were the decrease in energy consumption across all sectors in the U.S. economy, and the decrease in carbon intensity for electricity generation due to fuel switching from coal to natural gas, according to the report.
Other factors noted as contributors were a decrease in transportation sector emissions attributed to an increase in fuel efficiency across different transportation modes and limited new demand for passenger transportation.
According to the report, GHG emissions in 2012 showed a 10 percent drop below 2005 levels.
The EPA prepares the annual report in collaboration with other federal agencies and after gathering comments from stakeholders across the country. In addition to tracking U.S. GHG emissions, the inventory also calculates carbon dioxide emissions that are removed from the atmosphere through the uptake of carbon in forests, vegetation, soils, and other natural processes (called carbon “sinks”).