Despite persistently high oil prices, global energy demand will grow by 50 percent over the next two decades with continued heavy reliance on environmentally troublesome fossil fuels, especially coal and oil, the government predicted Wednesday.

The report forecast the steepest increases in China and other emerging economies where energy demand is expected to be 85 percent greater in 2030 than it is today.

"What jumps out is the very strong growth in the emerging economies," said Guy Caruso, head of the federal Energy Information Administration, which conducted the long-term energy outlook.

The projections said that without mandatory actions to address global warming, the amount of heat-trapping carbon dioxide flowing into the atmosphere each year from energy use will be 51 percent greater in 2030 than it was three years ago.

"Fossil fuels ... are expected to continue supplying much of the energy used worldwide," the report predicts, in spite of the growth of renewable energy sources, especial wind and biofuels.

"Global energy demand grows despite the sustained high world oil prices that are projected to persist over the long term," said the report. Oil could cost as little as $113 a barrel or as much as $186 a barrel in 2030, the analysis assumed in making the demand forecast.

Adjusted for inflation, the $113 price would be about $70 in 2006 dollars, the report said. "We're not going back to the historically low prices we saw in the '80s and '90s," said Caruso. He said the EIA price estimates are not firm predictions, but assumptions of what costs are likely to be in the long term.

The report provided both high and low price scenarios because of the uncertainties of projecting future long-term energy prices. Given current oil prices, the report says world oil prices appear on a path that more closely resembles the higher price scenario of $183 a barrel oil in 22 years.

Caruso said the analysis shows the importance of oil prices over the long term. He said while oil consumption will increase, the forecast projects demand to be about 10 million barrels a day less at the higher price assumption.

Still, the report predicted continued growth of petroleum use in transportation and heavy coal use to produce electricity.

The report assumes in its analysis no additional measures to curtail carbon dioxide emissions to address climate change.

The expected growth in energy demand is especially dramatic in developing countries, led by China, that are expected to have continued strong economic growth over the next two decades.

For example, the use of coal worldwide is expected to increase at a rate of 2 percent a year. China alone will account for nearly three-fourths of that increase, the report said.

Despite coal burning's significant impact on climate change "it's the fuel of choice for electricity production in the emerging economies, especially China," Caruso said at a meeting held by the Center for Strategic and International Studies.

The world's demand for liquid fuels — mostly oil — will continue to grow to 113 million barrels a day by 2030, nearly a third more than is consumed today.

Unconventional oil such as oil shale and biofuels such as ethanol should grow to nearly 10 percent of total liquid fuels. Still, with continued demand for conventional crude oil, the OPEC cartel is expected to increase production at a pace that will keep its 40 percent market share, the report predicts.

It also projects:

— Electricity production from nuclear power plants growing by one-third with the addition of 124 new nuclear power plants by 2030, as many as 45 of them in China, 17 in India, 18 in Russia and 15 in the United States.

— Natural gas "will replace oil wherever possible" especially in industrial uses, causing demand to grow for the fuel, which has less of a greenhouse gas impact than other fossil fuels.

— A growth in the demand for liquefied natural gas, or LNG, with production concentrated in the Middle East and Africa.

— A 2.1 percent annual growth in renewable energy for electricity generation, but mostly because of increases in the use of hydroelectric power in developing countries.