The EPA on Wednesday released its annual national greenhouse gas inventory, which finds that overall emissions during 2007 increased by 1.4 percent from the previous year. The report, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007, has been submitted to the Secretariat of the United Nations Framework Convention on Climate Change, which sets an overall framework for intergovernmental efforts to tackle the challenge posed by climate change.

Total emissions of the six main greenhouse gases in 2007 were equivalent to 7,150 million metric tons of CO₂. These gases include CO₂, methane, NO_X, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. The report indicates that overall emissions have grown by 17.2 percent from 1990 to 2007.

The increase in emissions in 2007 was due primarily to an increase in CO₂ emissions associated with fuel and electricity consumption, the agency said. The following factors were primary contributors to this increase: (1) increased demand for heating fuels and electricity due to cooler winter and warmer summer conditions in 2007 than in 2006; (2) increased consumption of fossil fuels to generate electricity; and (3) a significant decrease (14.2 percent) in hydropower generation used to meet this demand.

The inventory also calculates CO₂ emissions that are removed from the atmosphere by "sinks," e.g., through the uptake of carbon by forests, vegetation and soils.

Links

• Information on the greenhouse gas inventory report