Rio Tinto Group and U.S. utilities are urging the government to spend $20 billion on a technology they say has the best chance for eliminating pollution linked to global warming. The energy companies are lobbying Congress to help create devices that can trap carbon dioxide from coal-fired power plants and bury the gas in underground caverns. Environmental groups, labor unions and members of Congress from coal states say pilot projects won't begin without U.S. support that is unlikely to come this year. As the Senate today begins debating the first U.S. curbs on greenhouse gases blamed for climate change, coal companies say they won't provide most of the money for capture-and-storage technology. The industry has spent ``tens of millions of dollars,'' on development, and it's too costly for companies alone to finance, said Rio Tinto Chief Executive Officer for Energy Preston Chiaro.

``We can't do it without government support for the early projects,'' Chiaro, who also is chairman of the London-based World Coal Institute, said in a May 29 interview in New York. ``Shareholders simply won't stand for it unless there's a commercial return.'' The institute is an international trade group for coal producers such as London-based Rio Tinto. Power plants are the world's biggest source of carbon dioxide, the principal greenhouse gas blamed for global warming, after vehicles, according to the Paris-based International Energy Agency. Rising temperatures driven by human greenhouse- gas emissions are causing Arctic ice to melt and rain to decline in Africa and the Mediterranean, United Nations-sponsored researchers said in 2007.

Deeper Hole

Coal-burning plants supply about half of U.S. power demand. Taxpayer dollars would be better spent on reducing greenhouse gases by expanding solar and wind power, said Arjun Makhijani, president of the Institute for Energy and Environmental Research of Takoma Park, Maryland. He suggests linking the wind-rich Midwest part of the U.S. to cities that require more electricity instead of building expensive gas-scrubbing machinery. "There's no shortage of energy sources with low carbon dioxide,'' Makhijani said. ``If we're going to invest in something that isn't going to pay off for 15 or 20 years, we're going to dig a much deeper hole and make it much more costly to solve the problem.''

Fifteen years of tests are needed before capture and storage can be installed at generators, the U.S. Energy Department has said. Worldwide, $4 billion a year is needed for pilot projects, quadruple the current spending, said Howard Herzog, principal research engineer at the Massachusetts Institute of Technology's Energy Initiative, who has studied carbon capture since 1989.

$4 Billion Needed

"I don't think it's a question of the fundamental science,'' Herzog said in a May 30 interview. ``It's a question of the commercial viability of doing this in an integrated fashion and at a large scale.'' One method would trap CO2, the chemical name for carbon dioxide, and pressurize it into a liquid that's injected underground. There the substance would dissolve in brine, form lumps of carbonates or be absorbed in porous rock, according to a report by the Arlington, Virginia-based Pew Center on Global Climate Change. The U.S., Canada, Australia and Algeria have dabbled in capture-and-storage experiments. The most advanced U.S. project, called FutureGen in Illinois, was suspended this year after the government balked at the project's $1.8 billion pricetag.

Dabbling in Experiments

The U.S. coal industry's pitch for public funding is beginning to gain support. Climate change legislation co- sponsored by Connecticut Independent Joseph Lieberman and Virginia Republican John Warner provides $15.7 billion for research into carbon capture through 2050 and $307 billion to help coal utilities ``transition to the new low-carbon economy.'' The bill is set for debate beginning today. While coal companies already have spent ``tens of millions'' of dollars on tests so far, they need $1 billion of public money a year for 20 years until the technology is proven, the coal institute's Chiaro said. The bill is a first step in climate legislation for the U.S., which has rejected the Kyoto Protocol, an emissions limiting accord among industrialized countries. The Senate measure faces opposition from President George W. Bush and House members who are drafting their own climate change bill.

Wind and Solar

``This isn't going to pass this year,'' Ned Helme, president of the utility industry-funded Center for Clean Air Policy in Washington, said at a May 28 press conference. Doubling the annual research budget to $100 million for wind energy would provide turbines that supply 20 percent of the nation's power by 2030, said Liz Salerno, manager of policy analysis for the Washington-based American Wind Energy Association. Wind and solar together now supply just 2.4 percent of electricity demand. That would require changing priorities in Congress. Tax credits for power produced from coal and natural gas totaled $13.7 billion from 2002 to 2007, versus $2.8 billion for renewable generation, according to an October 2007 study by the Government Accountability Office, Congress's investigative arm. In the same period the U.S. Energy Department spent $1.4 billion for research on windmills and solar devices, compared with $3.1 billion on technology to cut emissions from coal.

Coal Interests

"You've got 150 to 200 members of the U.S. Congress with coal in their district and at the moment only one or two with solar-thermal,'' Representative Jay Inslee, a Democrat from Washington, said in a May 15 interview. ``We have to accommodate some realities. "Mandatory cuts in greenhouse gases without new systems to burn coal cleanly will force utilities to use natural gas, a fuel with limited domestic supplies, said Representative Rick Boucher, a Democrat from Virginia, a coal-mining state. "The inevitable result would be a tremendous spike in natural gas prices,'' Boucher said in an interview May 15. "That would wreak economic havoc across the economy.''

Avoiding catastrophic climate change may be more important than skirting high energy prices, say scientists including James Hansen, director of NASA's Goddard Institute for Space Studies. Hansen, who in 1981 warned that global-warming emissions were heating the planet faster than forecast, has joined environmental groups in calling for a faster transition to clean energy. "There's enough CO2 and fossil fuels in the ground to destroy the planet,'' Hansen said. "We've got to be thinking beyond that.'