The USA has rolled back its carbon emissions by 11 years. US carbon emissions peaked in 2007 at 6,022 million metric tons but will likely fall to 2000 or before levels in 2011, according to the most recent EIA data. Based on the first 6 months of this year, total emissions in 2011 will be around 5,600 million metric tons.
Is this decline temporary or a permanent trend toward lower emissions? Some would insist that the weak economic growth from 2000 to 2007, followed by the sharp fall in GDP from the 4th quarter of 2008 to the end of 2009, and capped off by more weak GDP gains since July 1, 2009 explain the emission reductions.
While some of the emission decline is a function of slow economic growth, the bottom line is that the US economy in 2011 is bigger than in 2000, and our population has grown by 30 million people as well. Slow economic growth is still growth.
Rolling the emission clock back 11 years to 2000 levels is more the result of the significant reductions in carbon needed to produce a dollar of GDP. Increased energy efficiency in electric power, transportation, and all parts of society, increases in production of zero carbon fuels like nuclear, wind, geothermal, and gas substituting to some degee for coal in power power production mean that both our economy can grow and carbon emissions can fall.
The likely 2011 declines in carbon emissions are similar in both the electric power and transportation sectors, roughly 7% compared to peak emissions in 2007 and both back to 2000 or before levels.
To reach 1990 levels, 2011 emissions would need to fall about another 15%. Efficiency in using fuel, substituting biofuels, natural gas and electicity for oil in transportation, and more renewables and gas to replace old coal plants could achieve cost effectively such reductions and boost our economy.