US Greenhouse Gas Emissions are Down
Anthropogenic US greenhouse gas emissions (GHG) amounted to a CO2-equivalent 6,702.3 million metric tons in 2011, down 1.6 percent from 2010 and 6.9 percent below 2005 levels. Longer term, US GHG emissions have increased at an annual average rate of 0.4 percent since 1990, according to the Environmental Protection Agency's (EPA) 18th annual US Greenhouse Gas Emissions and Sinks (Inventory) report, which was released April 15.
A decrease in the carbon intensity of fuels used in electricity generation due to increased use of natural gas as opposed to coal, a "significant increase in hydropower" generation, and "relatively mild winter conditions, especially in the South Atlantic Region of the US" were the main factors underlying the drop in national GHG emissions in 2011, according to the EPA’s "The Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011."
Longer term trends from 1990 through 2011 were attributed to lower emissions from electricity generation, higher vehicle fuel efficiency and less in the way of miles traveled, and year-to-year changes in weather patterns.
Anthropogenic, or human-caused, GHG emissions have been identified as the main drivers of climate change, the immediate economic, social and environmental costs and long-term threats of which have become increasingly apparent.
For 18 years, the US EPA has been tracking total emissions of the six main GHGs in its annual Greenhouse Gas Emissions and Sinks (Inventory) reports: carbon dioxide (CO2), methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride.
Power plant plumes via Shutterstock.
Read more at ENN Affiliate, Global Warming is Real.