Energy Intensity

figure dataPopulation is a key determinant of energy consumption through its influence on demand for travel, housing, consumer goods, and services. U.S. energy use per capita was fairly constant over the 1990 to 2007 period, but it began to fall after 2007. In the AEO2012 Reference case, energy use per capita continues to decline due to the impact of an extended economic recovery and improving energy efficiency. Total U.S. population increases by 25 percent from 2010 to 2035, but energy use grows by only 10 percent, and energy use per capita declines at an annual average rate of 0.5 percent per year from 2010 to 2035 (Figure 9).

figure dataFrom 1990 to 2010, energy use per dollar of GDP declined on average by 1.7 percent per year, in large part because of shifts within the economy from manufactured goods to the service sectors, which use relatively less energy per dollar of GDP. The increase in dollar value that the service sectors add to GDP (in constant dollar terms) was 15 times the corresponding increase for the industrial sector over the same period. As a result, the share of total shipments accounted for by the industrial sector fell from 30 percent in 1991 to 22 percent in 2010. In the AEO2012 Reference case, the industrial share of total shipments fluctuates in a narrow range between 22.1 and 23.4 percent from 2011 through 2025, then declines slowly to 20.7 percent in 2035 (Figure 10). Energy use per 2005 dollar of GDP declines by 42 percent from 2010 to 2035 in AEO2012 as the result of a continued shift from manufacturing to services (and, even within manufacturing, to less energy-intensive industries), rising energy prices, and the adoption of policies that promote energy efficiency.

CO2 emissions per 2005 dollar of GDP have historically tracked closely with energy use per dollar of GDP. In the AEO2012 Reference case, however, as lower carbon fuels account for a bigger share of total energy use, CO2 emissions per dollar of GDP decline more rapidly than energy use per dollar of GDP, falling by more than 50% from 2005 to 2035, at an annual rate of 2.3 percent per year.