Total U.S. greenhouse gas (GHG) emissions were 7,147.2 million metric tons carbon dioxide equivalent (MMTCO2e) in 2005, an increase of 0.6 percent from the 2004 level. Since 1990, GHG emissions have grown at an average annual rate of 1.0 percent.
Total estimated U.S. GHG emissions in 2005 consisted of 6,008.6 million metric tons of carbon dioxide (84.1 percent of total emissions), 611.9 MMTCO2e of methane (8.6 percent of total emissions), 366.6 MMTCO2e of nitrous oxide (5.1 percent of total emissions), and 160.2 MMTCO2e of hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6) (2.2 percent of total emissions), according to EIA.
U.S. GHG emissions per unit of Gross Domestic Product (GDP), or “U.S. GHG-intensity,” fell from 664 metric tons per million 2000 constant dollars of GDP (MTCO2e/$Million GDP) in 2004 to 647 MTCO2e /$Million GDP in 2005, a decline of 2.5 percent, says the report. Since 1990, the annual average decline in GHG-intensity has been 1.9 percent.
The 2005 emissions increase is well below the rate of economic growth of 3.2 percent, says EIA. Emissions of carbon dioxide from energy consumption and industrial processes, which have risen at an average annual rate of 1.2 percent per year since 1990, grew by only 0.3 percent in 2005.
Slow growth in carbon dioxide emissions from 2004 to 2005 can be attributed mainly to higher energy prices that suppressed energy demand, low or negative growth in several energy-intensive industries, and weather-related disruptions in the energy infrastructure along the Gulf Coast that shut down both petroleum and natural gas operations, according to EIA. Emissions of methane increased by 0.9 percent, while emissions of nitrous oxide rose by 1.9 percent. Emissions of HFCs, PFCs, and SF6, a group labeled collectively as “high-GWP gases” because their high heat trapping capabilities, rose by 7.2 percent.
