Most encouraging article I have read in a while: U.S. Carbon Emissions Down Seven Percent in Four Years.
Due to a combination of the economic recession, EPA regulations, businesses embracing environmentally-friendly innovation, and more,
"We are now looking at a situation where the seven percent decline in carbon emissions since the 2007 peak could expand to 20 percent by 2020, and possibly even to 30 percent. If so, the United States could become a world leader in cutting carbon emissions and stabilising climate."
This article's, from Nation of Change, strength is in its analysis of the social and economic trends which have led to America's environmental progress.