Looks like the U.S.’s dismal economy had some positive fallout after all. At least as far as air quality is concerned.
According to the EPA’s 16th annual US Greenhouse Gas Inventory Report released today, overall emissions during 2009 decreased by 6.1 percent from the previous year. The report attributes this downward trend to “a decrease in fuel and electricity consumption across all US economic sectors.”
Total emissions of the six main greenhouse gases in 2009 were equivalent to 6,633 million metric tons of carbon dioxide. These gases include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. Not surprisingly, CO2 from fossil fuel combustion continues to be the largest source of the nation’s human activity-related greenhouse gas emissions, representing about 83 percent of total emissions.
But the good news is, that while overall emissions have increased by more than 7.3 percent from 1990 to 2009 (growing at an average annual rate of 0.4 percent), 2009 saw the lowest total annual greenhouse gas emissions since 1995.
The report also attributes the low emissions in part to “a reduction in carbon intensity of fuels used to generate electricity” or “fuel switching.” Apparently the rising price of coal has led many power companies to increase use of the more cheaply available natural gas – a fuel that has its own emissions and water pollution issues (The report does say that natural gas systems were the largest anthropogenic source category of methane emissions in the United States in 2009. Methane emissions from these systems increased 4 percent from 2008 to 2009 due to an increase in production and production wells).
All those efforts to compost our food scraps and plant trees are paying off too. The report says capturing carbon “in forests, trees in urban areas, agricultural soils, and landfilled yard trimmings and food scraps,” together helped offset 15.3 percent of total emissions in 2009.
The takeway: Individual efforts do make a difference and slowing down growth isn’t always a bad idea. Excuse me while I go add that banana peel sitting on my desk to the kitchen compost heap.
This post was originally published by the Earth Island Journal.