WASHINGTON -- The Environmental Protection Agency says greenhouse gas emissions in the United States showed a 1.6% decline from 2010 to 2011.
The decrease continued an overall decline in U.S. greenhouse gas emissions, down 6.9% since 2005. The EPA said the drop from 2010 to 2011 is driven mostly by power plants switching from coal to natural gas, which emits less carbon dioxide when burned. Additionally, a mild winter in the south Atlantic region of the U.S., where much of the heating is electric, resulted in lower electricity demand.
Power plants are the single biggest source of greenhouse gases, with 33%. The transportation sector is second, with 28% of emissions.
Increases in vehicle fuel economy through 2025 should reduce transportation emissions even further. Greater switching to natural gas from coal will cut power plant emissions. President Obama has pledged to reduce U.S. greenhouse gas emissions 17% below 2005 levels by 2020. Despite the general decline in greenhouse gas emissions, many experts contend that the administration would have to take further steps to meet the 2020 goal.
On Monday, the EPA confirmed that it had missed a deadline to pass a final rule to cut carbon dioxide emissions from new power plants. The EPA did not provide an explanation for the delay.
Once the new rule is in place, the EPA can propose a rule for existing power plants. Carbon dioxide accounts for 84% of total greenhouse gas emissions, followed by methane at 9%, according to the EPA.