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 from 1990 to 2007, but it began to fall after 2007. In the AEO2013 Reference case, energy use per capita continues to decline due to the impacts of improving energy efficiency (e.g., new appliance and CAFE standards) and changes in the ways energy is used in the U.S. economy. Total U.S. population increases by 29 percent from 2011 to 2040, but energy use grows by only 10 percent, with energy use per capita declining by 15 percent from 2011 to 2040 (Figure 8).

From 1990 to 2011, 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 dollar-value increase in the service sectors (in constant dollar terms) was 16 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 2011. In the AEO2013 Reference case, the industrial share of total shipments reverses the earlier trend, largely due to the benefits of increased domestic production of natural gas, and increases to more than 23 percent in 2016. After 2016, however, the share resumes its decline, falling to less than 22 percent in 2040. Energy use per 2005 dollar of GDP declines by 46 percent from 2011 to 2040 in AEO2013 as the result of a continued shift from manufacturing to services (and, even within manufacturing, to less energy-intensive manufacturing 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 AEO2013 Reference case, however, as lower-carbon fuels account for a larger share of total energy use, CO₂ emissions per 2005 dollar of GDP decline more rapidly than energy use per 2005 dollar of GDP, falling by 56 percent from 2005 to 2040, at an annual rate of 2.3 percent per year.