Update: US Emissions Continue to Decline on the Back of Natural Gas

Earlier this month, the Energy Information Administration (EIA) announced that the US produced more electricity from natural gas than from coal in April thanks to the dramatic shale-driven decline in natural gas prices. Today, EIA released complete April energy sector data and, as you might expect, US CO2 emissions have declined alongside coal’s market share, continuing a trend we discussed in our May 7 note. Power sector CO2 emissions are down 12% from a year ago and total US CO2 emissions have declined by 6%. Measured against 2005 (the base year used for America’s international climate change commitments) and January-April CO2 emissions are down 19% and 14% for the power sector and the economy as a whole respectively.

As we discussed in May, this isn’t just a power story. High oil prices, low natural gas prices and new efficiency standards have reduced CO2 emissions in the residential, commercial, industrial and transport sectors as well relative to 2005 (Figure 1). But power has delivered reductions as large as these other sectors combined. And within power, natural gas and renewables have delivered comparable gains when measured against the generation mix in 2005.

A third of the decrease in emissions since 2005, however, occurred during the last year alone. And three quarters of this drop was due to fuel switching in the power sector (Figure 3).  Between April 2011 and April 2012, coal’s share of US power generation declined from 41% to 32%. Nearly all this market share went to natural gas, which accounted for 32% of power generation in April 2012, up from 23% a year prior (Figure 4). Renewables generation fell by 9% in absolute terms during that period, despite 90% growth in solar generation, thanks so a drop in hydro production and meager growth in wind power generation (Figure 5).