WASHINGTON, May 21, (UPI) -- Since President Bush said in March that he would no longer consider controls on carbon dioxide emissions, the administration has realized it must address the issue. The administration's energy policy report mentions greenhouse gases seven times and carbon dioxide or carbon equivalents eight times.

A cabinet-level task force studies global climate change in weekly sessions. Staunch defenders of the president's energy policy, such as White House spokesperson Tucker Eskew and Republican Senator Pete Domenici of New Mexico, make a point of the benefits of reducing greenhouse gases. An increased level of carbon dioxide (CO2) in the atmosphere, mostly from burning carbon-based fuels, is generally thought to be causing global warming.

Carbon dioxide from power plants and factories can be captured and stored using techniques that exist today. Estimates of the additional cost to electricity vary from increasing it by 1.5 cents per kilowatt to a doubling of the cost. Underground storage is the most commonly contemplated approach. Pumping CO2 into the ocean is more controversial. Planting forests would deal with only a small fraction of the problem.

The Department of Energy is exploring a number of technologies for permanent CO2 storage, called sequestration, but the question of when the techniques would be widely used is unanswered.

Rita Bajura, director of DOE's National Energy Technology Laboratory (NETL) in Pennsylvania and West Virginia, told United Press International, "The technical capability is tied up with policy. There is no requirement at this time to manage carbon, so there's no real time frame. The time frame that it happens in is really driven by the policy. The policy would announce the depth of carbon removal that would be required. That would directly drive the price and drive the time frame."

Bajura told UPI that capturing and sequestering carbon dioxide in a coal-fired plant "would perhaps double the price of power generation." There are no official estimates of how widespread the technology might be applied in the future, Bajura said, adding, "We're starting to have people look at what is possible and what portfolio of technologies might make it possible to achieve any levels of carbon reduction that the policy might dictate." The NETL program "is targeted to provide designs of advanced plants and the technologies to start putting them together in 2015, so we're looking maybe 15 years out," Bajura added.

Carbon dioxide can be captured by bubbling the gas produced in a coal-fired or gas-fired plant through an amine solution. The liquid is then treated and the carbon dioxide removed and concentrated. Food-grade carbon dioxide used by soft-drink manufacturers is currently made at a few power plants.

The equipment is not cheap. According to Carl Mariz of Fluor Daniel, a company that designs and builds power plants and refineries, the cost of a plant could increase by $100 million for a 400 megawatt (400 million watt) power plant normally costing $200 million, if CO2 capture equipment were required. Electricity costs, which vary in the United States from 5 to 15 cents per kilowatt hour, would increase about 3 cents per kilowatt hour, according to Mariz. The process itself would consume 20 to 30 percent of a plant's electricity.

After the carbon is captured and concentrated, it can be injected into the ground. While this is proven technology, used for years by oil companies to force oil deposits out of rock, there remain questions about how permanently the CO2 will remain in the rock formation. Not every power plant or factory will be located on top of an appropriate geological formation for storage. Pipelines, at about a million dollars a mile, will be needed.

Neeraj Gupta of the Battelle Memorial institute in Columbus, Ohio, is studying sandstone formations as a potential sequestration site. Taking into account CO2 capture, piping, and injection, and assuming the electricity generating source was an advanced gas-fired turbine, then costs would be about 30 to 40 dollars per ton of CO2, Gupta told UPI. This translates into about 1.5 cents per kilowatt hour. An advanced gas turbine produces about one-third of a ton of CO2 per every million watts produced while coal-fired electricity produces about a ton of CO2 per million watts, making CO2 removal from coal two to three times more expensive.

"All of these technologies are mature now, if you're willing to pay enough money. If you are willing to wait, then they might get cheaper . . . With the new energy policy there could be an explosion of new power plants coming on line," Gupta said. Plans need to be made to, at the very least, allow these technologies to be added in the future, he added.

Enough storage for 100 to 200 years of power plant emissions, at current levels, is thought to exist in the U.S.
Pumping the CO2 into the ocean is regarded with a range of attitudes ranging from caution to alarm. Some very preliminary experiments have begun. The big problem is that carbon dioxide causes ocean water to become more acid.

According to Kenneth Caldeira, co-director of DOE research on ocean carbon sequestration at Lawrence Livermore National Laboratory, after about 500 to 1000 years, such a practice would approximately double the acidity of the world's oceans. It is not known what effect this would have on marine life. Caldeira told UPI, "Nobody's arguing that it's good to put CO2 in the ocean. People are just arguing that its probably not as bad as putting it in the atmosphere."

Planting trees is often spoken of as an option, since trees store carbon in wood. U.S. forests absorb about 236 million tons of carbon annually, according to the U.S. Forest Service, about 14 percent of annual U.S. carbon dioxide emissions. Thirty percent of the U.S., about one million square miles (2,600,000 sq. km), is in forest and woodlands. By planting additional forests on an additional million square miles, another 14 percent annually could be removed for a while. But as the DOE points out, as the trees mature the process slows. When trees burn they release much of the carbon back into the atmosphere.

Each day, every person in the United States produces, on average, about 30 pounds of CO2. As a nation, this results in about three trillion pounds a year, or 1.6 billion tons of CO2. Electricity generation produces about one-third of the total, with coal producing 90 percent of electricity's CO2 emissions. Transportation fuels produce about one-third. Industrial use of natural gas produces about one-tenth the total CO2.

A tripling of atmospheric CO2 concentrations, widely believed to be possible by 2100, if there is no change in the policies of governments around the world, would most likely result in a global average temperature increase of 8 degrees Fahrenheit (4.5 degrees Centigrade), according to the United Nations Intergovernmental Panel on Climate Change. Such an increase would likely be associated with catastrophic crop failure, droughts, severe storms, flooding and a rising ocean level.

Copyright 2001 by United Press International.