U.S. carbon dioxide emissions continue to drop, reaching levels not seen since the early 1990s, according the Energy Information Administration (EIA). The deep economic recession accounts for some of this decline, but it is illustrative to note that U.S. gross domestic product has posted growth since late 2009 (see http://www.tradingeconomics.com/united-states/gdp-growth). Even assuming for lags in industrial production, and the related transport and distribution of goods, at some point, this trend ought to have reversed and shown emissions growth if the recession were the major explanation for emissions trends.
EIA summarizes competing explanations at http://www.eia.gov/environment/emissions/carbon/. EIA finds that “The carbon intensity of the energy consumed declined in every sector of the economy” and “With the exception of the transportation sector, this decline was influenced by the decline in the carbon intensity of the electric power sector.” In the electric power sector, EIA rightly points to the dramatic decrease in coal useage as the principle explanation for the decline in carbon intensity. Coal use dropped by over 100,000 million kWh, while natural gas, wind, and solar all saw noticeable increases.
In a 2012, Marshall Institute study, Changes in the Fuel Mix Used to Produce Power in the U.S., Dr. Michael Canes documents the changing composition of the U.S. energy supply and discusses the forces driving this transformation. Dr. Canes observes: “The purpose is to see whether such mix already is being shaped by market forces that are driving it towards lower carbon content. If so, question arises whether there is any need for policy measures such as Renewable Portfolio Standards or subsidies for non-carbon sources. Further, as mandates or subsidies have substantial costs, question arises whether these costs are justified.”
Canes finds that “Markets already are responding to price signals in such a way as to yield a less carbon intensive power mix, and projections indicate this is likely to continue.”
“Dr. Canes’ paper demonstrates the folly of government attempts to legislate targets and time tables for the development and deployment of energy technologies,” Institute CEO William O’Keefe observed.
“The paper clearly shows that market forces and innovation are a better way to achieve energy and environmental objectives,” O’Keefe concludes. “The long-term decline in carbon intensity provides strong evidence of that view.”