US carbon emissions rose slightly due to cold winter

US EIA

Last year, the US Energy Information Agency suggested that emissions of carbon dioxide by the US had peaked in 2005 and were unlikely to return to such heights. So far, that prediction has held up, although there have been some bumps in the road. The year 2013 appears to have been one of those bumps, as emissions increased for the first time since 2010, reaching levels not seen since last decade. But there are many pieces of good news in the details.

To begin with, the EIA blames the boost in emissions, which came in at a 2.5 percent increase, primarily on the heavy use of heating during last year's unusually cold winter. A secondary factor was a rise in natural gas prices that shifted some electricity generation to coal (more on that later). The increase in emissions, however, wasn't tied to economic growth. While the GDP per capita went up by 1.5 percent, the energy use per GDP only went up by 0.5 percent; in turn, the carbon dioxide intensity of energy production actually declined slightly.

So, to an extent, carbon emissions have been decoupled from economic growth. They've also been somewhat decoupled from electricity use. Demand has decreased in recent years, in part due to a decrease in industrial activity, in part due to increased efficiency. A switch to natural gas has also decreased the carbon emissions per unit of generation, although, as noted above, this trend reversed slightly last year.