Oct. 12--South Carolina is generating more hot air than ever. Fueled largely by gases from coal-fired power plants and vehicles, the state has increased its carbon dioxide emissions, the main contributor to global warming, by 45 percent since 1990, a Post and Courier analysis shows.

By some measures, only two other states' carbon footprints grew faster than South Carolina's.

In 1990, South Carolina's power plants, factories, vehicles and other carbon dioxide sources cranked out 61 million tons of carbon dioxide. In 2007, these sources released 89 million tons, an increase of about 28 million tons, the newspaper's analysis of U.S. Energy Information Administration data shows.

Power plants and vehicles were responsible for most of this additional carbon dioxide, while emissions from homes, commercial businesses and industries remained relatively stable.

South Carolina's overall increase comes amid a solidifying consensus among scientists that man-made greenhouse gases will cause catastrophic changes to the climate in 30 to 40 years unless emissions are reduced soon.

The state's dependence on coal-powered electric generators also puts it squarely in the debate over federal energy legislation and raises important questions about the state's portfolio of energy sources.

A large share of South Carolina's increase in carbon dioxide emissions happened as Santee Cooper expanded its Cross plant in Berkeley County and South Carolina Electric & Gas built a new plant near Orangeburg to meet the state's growing demand for power.

In 1999, for instance, Santee Cooper's coal plants burned 6.4 million tons of coal a year, the utility says. Last year, its plants consumed 9.1 million tons. Its carbon dioxide emissions increased by nearly 6 million tons during this decade.

Santee Cooper officials noted that it serves three of the fastest-growing counties in the state, and that the number of retail customers increased by 80 percent from 1990 through 2007. Its energy sales nearly doubled during this time.

As prices for natural gas rose after 2002, "coal was the clear choice for reliable, affordable new generation," said Mollie Gore, publications director for Santee Cooper. She said the utility has been working to diversify its fuel sources through renewable resources and nuclear power. The utility also recently decided to nix its $1.2 billion Pee Dee coal plant partly over concerns about federal efforts to regulate carbon dioxide through a cap-and-trade program.

Another big carbon dioxide emitter, SCE&G, saw its emissions spike in 2006 at 16 million tons and decrease to a projected 10 million tons this year, said Scott Grigg, supervisor of public affairs for Scana Corp., SCE&G's parent company. Grigg cited the economic downturn and the utility's shift toward natural gas for the decline.