Proposed coal-fired power plants in Nevada and other Western states will damage the environment and become more costly because of anticipated carbon dioxide pollution regulations, environmental groups said Tuesday.

"The American Southwest is at a pivotal crossroads," said Vickie Patton, one of the authors of the study, "Climate Alert: Cleaner Energy for the Southwest." Western Resource Advocates and Environmental Defense, both of Boulder, Colo., published the report.

"We can either saddle our children with a staggering amount of global warming" or work to reduce it, Patton said.

The environmental groups identified the $3.8 billion, 1,500-megawatt Ely Energy Center as a key coal-fired power plant they oppose. The Ely center and the other 12 new and proposed pulverized-coal plants would spew out 69.9 million tons of carbon dioxide yearly, increasing global warming, the report says.

The Ely center would throw off 12.6 million tons of carbon dioxide yearly, according to the report.

"If built as proposed, the Ely plant would be the largest producer of greenhouse gas emissions among the proposed new coal-fired plants in the Southwest," the report says.

The Ely plant also would consume 2.6 billion gallons of water yearly, the report says.

Desert Rock, a plant being developed by Sithe Global Power and the Navajo Nation enterprise Diné Power Authority, is another big proposal, with 1,500 megawatts of capacity. Sithe also has a proposal to build the 750-megawatt Toquop Energy Project near Mesquite. LS Power plans to build a 650-megawatt, coal-fired plant near Ely, but must have a long-term contract with Nevada Power, wholesalers or another entity before it can be built, the study said. Newmont Mining Corp., which operates gold mines in Nevada, has a 200-megawatt, coal-fired plant at Dunphy.

The other plants are in Arizona, New Mexico, Colorado and Utah.

The Public Utilities Commission last year authorized Nevada Power Co. and Sierra Pacific Power Co. to spend $300 million to start developing the coal-fired Ely plant.

It's unclear whether Gov. Jim Gibbons supports the Ely coal plant. Brent Boynton, the governor's spokesman, referred questions about the Ely Energy Center to Hatice Gecol, Gibbons' energy and science adviser. She did not return calls.

Roberto Denis, senior vice president of Sierra Pacific Resources, parent company of the two electric utilities, said the company's energy strategy and the Ely project are consistent with the environmental study.

John Nielsen, energy project director for Western Resources, rejected Denis' conclusion, saying the environmental groups oppose construction of the Ely coal plant.

"The Ely Energy Center is exactly the kind of facility that is of concern in terms of global warming emissions," Nielsen said.

Denis referred to a list of seven recommendations in the report and mentioned ways in which the Nevada utilities are following the recommendations. The report recommended greater reliance on energy conservation, use of more renewable energy, and building transmission lines that provide access to renewable resources. A transmission line being built to carry power from the Ely coal plant also could be used to tap 300 megawatts of wind power in the Ely area, Denis said.

The report recommends that coal-fired plants use technology to capture carbon emissions. Denis said the Nevada Power and Sierra Pacific Power set aside space for installing carbon capturing equipment when the technology becomes feasible. Sierra Pacific Resources also is participating with other utility companies in a study of retrofitting existing pulverized-coal power plants with carbon-capturing technology, Denis said.

Nielsen said it will not be feasible to retrofit pulverized-coal-fired power plants with equipment for capturing carbon.

In addition, Nielsen also said that pulverized-coal plants like the Ely center are becoming more costly to build and operate.

Congress is talking about a cap-and-trade system of regulating carbon dioxide pollution. The total amount of carbon dioxide would be capped, and existing companies with carbon dioxide emissions would be able to use their carbon credits or sell them to the highest bidder.

Those regulations will add about 1 cent a kilowatt hour to the cost of power from coal-fired plants, Nielsen said. That would bring the cost of coal power to 6 or 7 cents a kilowatt hour, he said.

"It's a near certainty that we're going to see this regulation coming," Nielsen said.

Denis declined to speculate about the possibility Congress will pass and President Bush will sign a cap-and-trade regulatory system.

"We would be concerned about anything that impacts the cost to consumers," Denis said.

State consumer advocate Eric Witkoski said he was disappointed the utilities commission did not require the electric utilities to provide estimates of the cost of carbon regulation before approving $300 million in development expenses for the Ely project.

The environmental report's authors advocated using renewable energy -- such as solar, wind and geothermal power -- as well as energy conservation to meet the electricity needs of the rapidly growing Southwestern population.