The once tight link between carbon emissions and economic growth in the USA is breaking. Consider that since 1990 US GDP has grown 66%, but energy related carbon emissions have increased just 9%. www.eia.gov/environment/emissions/carbon/. While the link has been weakening year after year, as the carbon intensity of the US economy lessens, it completely broke in 2011.
Last year, US GDP increased 1.8% but carbon emissions fell 2.4%, according to the official 2011 EIA data. The carbon intensity, a measure of how much carbon is required to produce each dollar of GDP, declined 4.2%.
From 1990 to 2011, in those 22 years, carbon intensity has been steadily declining, but only 6 years saw carbon emission decreases--1991, 2001, 2006, 2008, 2009, and 2011.
Importantly, five of the 6 years with carbon decreases have taken place in the last 11 years. Four of the 6 years, however, were recessionary--1991, 2001, 2008, and 2009.
Two years--2006 and 2011--were non-recession years when GDP grew and carbon emissions fell. Almost certainly 2012 will become the third year when GDP grew and carbon pollution fell. What explains rising GDP and falling carbon emissions?
More natural gas, renewable energy, and energy efficiency are breaking the link between GDP growth and carbon pollution. What would completely shatter the link would be economic carbon capture and storage technology. Developing such technology should be a top priority for research and development in the USA and around the world.