Annual Energy Outlook 2006 with Projections to 2030 - Usinfo.org

Carbon Dioxide EmissionsHigher Energy Consumption ForecastIncreases Carbon Dioxide EmissionsFigure 107. Carbon dioxide emissions by sector andfuel, 2004 and 2030 (million metric tons)4,0008,114 Petroleum20045,900Natural gas2030Coal3,000ElectricityTotal carbon dioxideemissions2,0001,00002004 2030ResidentialCommercialIndustrialCO 2 emissions from the combustion of fossil fuels areproportional to fuel consumption. Among fossil fueltypes, coal has the highest carbon content, naturalgas the lowest, and petroleum in between. In theAEO2006 reference case, the shares of these fuelschange slightly from 2004 to 2030, with more coal andless petroleum and natural gas. The combined shareof carbon-neutral renewable and nuclear energy isstable from 2004 to 2030 at 14 percent. As a result,CO 2 emissions increase by a moderate average of 1.2percent per year over the period, slightly higher thanthe average annual increase in total energy use (Figure107). At the same time, the economy becomes lesscarbon intensive: the percentage increase in CO 2emissions is one-third the increase in GDP, andemissions per capita increase by only 11 percent overthe 26-year period.The factors that influence growth in CO 2 emissionsare the same as those that drive increases in energydemand. Among the most significant are populationgrowth; increased penetration of computers, electronics,appliances, and office equipment; increases incommercial floorspace; growth in industrial output;increases in highway, rail, and air travel; and continuedreliance on coal and natural gas for electric powergeneration. The increases in demand for energy servicesare partially offset by efficiency improvementsand shifts toward less energy-intensive industries.New CO 2 mitigation programs, more rapid improvementsin technology, or more rapid adoption of voluntaryprograms could result in lower CO 2 emissionslevels than projected here.TransportationElectricity generationEmissions Projections Change WithEconomic Growth AssumptionsFigure 108. Carbon dioxide emissions inthree economic growth cases, 1990-2030(million metric tons)10,0008,0006,0004,0002,000HistoryProjections01990 2004 2010 2020 2030High growthReferenceLow growthThe high economic growth case assumes highergrowth in population, labor force, and productivitythan in the reference case, leading to higher industrialoutput, higher disposable income, lower inflation,and lower interest rates. The low economicgrowth case assumes the reverse. The spread in GDPprojections increases over time, with GDP in thealternative cases varying by about 15 percent fromthe reference case in 2030.Alternative projections for industrial output, commercialfloorspace, housing, and transportation influencethe demand for energy and result in variations inCO 2 emissions (Figure 108). Emissions in 2030 are 10percent lower in the low growth case and 10 percenthigher in the high growth case. The strength of therelationship between economic growth and emissionsvaries by end-use sector. It is strongest for the industrialsector and, to a lesser extent, the transportationsector, where economic activity strongly influencesenergy use and emissions, and where fuel choices arelimited. It is weaker in the commercial and residentialsectors, where population and building characteristicshave large influences and vary less across thethree cases.In the electricity sector, changes in electricity salesacross the cases affect the amount of new, more efficientgenerating capacity required, reducing the sensitivityof energy use to GDP. However, the choice ofcoal for most new baseload capacity increases CO 2intensity in the high growth case while decreasing itin the low case, offsetting the effects of changes inefficiency across the cases.Energy Information Administration / Annual Energy Outlook 2006 103