ge 1990 1999 1990-1999 1998-1999 Transportation 431.8 496.1 14.9% 2.9% Industrial 454.8 481.2 5.8% 0.2% Commercial 207.7 243.5 17.2% -0.4% Residential 254.2 290.1 14.1% 0.4% Note: Electric utility emissions are distributed across sectors. Total carbon dioxide emissions from the residential sector increased by 0.4 percent in 1999 (Table 6). Year-to-year, residential sector emissions are heavily influenced by weather. For example, in 1996, a relatively cold year, carbon dioxide emissions from the residential sector grew by 5.9 percent over 1995. In 1997, they declined by 0.4 percent due to warmer weather. Carbon dioxide (CO2) is the most the most troublesome greenhouse gas that comes from human activities - mostly from burning hydrocarbon fuels. From the last ice age until the industrial revolution in the last century (about 10,000 years), the atmospheric level of CO2 had varied only about 5%. But beginning with the industrial revolution and projecting forward to about 2030, the amount of atmospheric CO2 will have doubled - all in about 150 years time. The atmospheric concentrations of several greenhouse gases are rising as a result of human activity. Carbon dioxide, the most important human-made greenhouse gas, is released primarily by the burning of fossil fuels like coal, oil, and natural gas. Its concentration has risen by nearly 30% over its value in pre-industrial times. Concentrations of other greenhouse gases have also risen; methane levels have more than doubled and nitrous oxide levels are increasing as well.Carbon dioxide is released to the atmosphere when solid waste, fossil fuels (oil, natural gas, and coal), and wood and wood products are burned. Each greenhouse gas differs in its ability to absorb heat in the atmosphere. HFCs and PFCs are the most heat-absorbent. Methane traps over 21 times more heat per molecule than carbon dioxide, and nitrous oxide absorbs 270 times more heat per molecule than carbon dioxide. Often, e...
