Seventy-four senators voted this week to begin debate on a sweeping bill to curb carbon emissions, but agreement on any point of law from now on gets tougher.
The terms of the debate have shifted dramatically from 2003 and 2005, when the Senate rejected previous moves to curb global warming.
Largely out of this week's debate are cries that global warming is a "hoax" or that claims that carbon emissions affect the climate are simply bad science. There's also broad agreement that Washington should increase investments in clean energy technology.
Instead, the fault line in this week's debate is the scope of the role for Washington in curbing emissions and its likely impact on the economy.
"Climate change is an issue that all of us are concerned about, but there's a right way and a wrong way to tackle the problem. And driving the price of gasoline even higher is clearly not the way to go," said Republican leader Mitch McConnell at a briefing on Tuesday.
GOP opponents say the proposed Senate bill will cost $6.7 trillion over the 50-year life of the bill and increase gas prices by anywhere from 53 cents to $1.40 a gallon by 2050, the result of which will be increased costs for American families and more manufacturing jobs sent to foreign countries.
"Unless we have the technology to make a steep and quick emissions cut that the sponsors want, this bill will do nothing but add $6.7 trillion, a tax increase on American families and workers," says Rep. James Inhofe (R) of Oklahoma, the leading opponent of global-warming legislation.
Supporters say the bill helps shift the US economy to a more diversified energy future and millions of "green jobs."
"Hundreds of thousands of new jobs in renewable energy have already been created by foresighted investors who see the need for clean energy that does not contribute to global warming," said Senate majority leader Harry Reid in the run-up to Monday's vote. The strong cap-and-trade system in the proposed bill could create millions more, he added.
But Democrats, too, face deep rifts within their caucus over how far Washington should move to address global warming. Lawmakers from states that produce or depend on coal for power worry that the technological advances may not come fast enough to meet the terms of the bill.
Sen. Byron Dorgan (D) of North Dakota is proposing an amendment to bump investment in new technologies from $17 billion to $37 billion to "unlock the mystery of carbon capture." "If we don't do this, this bill will fail," he said on the floor of the Senate on Wednesday.
While there's broad agreement on the need for more investment in solar, wind, geothermal, and biomass energies, expected amendments on the needs to relaunch a nuclear power initiative could also further splinter support for the bill.
On Tuesday, the Department of Energy (DOE) submitted a long-awaited license application to build a nuclear waste dump at Yucca Mountain in Nevada – a move that supporters say is essential to revive the nuclear-power industry.
Nuclear-power advocates hope to use the global-warming bill as a vehicle for reviving the industry. They make the case that without a significant increase in nuclear power, it will be impossible to lower carbon emissions without a blow to US living standards.
"It's time we begin the nuclear renaissance in America and Yucca Mountain is a vital step," said Sen. Jim DeMint (R) of South Carolina, in a statement after the announcement. "If Congress is serious about reducing carbon emission, nonemitting nuclear energy must play an even larger role than it does today."
Many Democrats are wary of risking the support of some environmental groups over nuclear power. Majority leader Reid, a longtime opponent of a nuclear-waste dump in his state, charged that DOE filed the application with only about 35 percent of the work done to justify it.
"Yucca Mountain is as close to being dead as any piece of legislation could be," he said on Tuesday. Republicans say they are holding out for a wide-ranging debate over the global-warming bill, including many amendments. Democratic leaders worry that some amendments, including those over nuclear power, could undermine support for the bill.
Commenting on the diverse coalition of lawmakers now supporting the bill, Sen. Barbara Boxer (D) of California said: "They need a certain amount to stay on it. I need a certain amount not to get off it. We're looking for that sweet spot."
Asked to clarify her position in nuclear power, Senator Boxer said on Wednesday, "Already in the bill there's a whole funding stream for these low-carbon, noncarbon energy sources and that's sufficient. I don't think you need more."
As chairman of the Committee on Environment and Public Works, Boxer is leading the floor debate on the global warming bill, known as the Lieberman-Warner Climate Security Act of 2008 after cosponsors Sens.
Joseph Lieberman (I) of Connecticut and John Warner (R) of Virginia.
"Some of my colleagues want to add more to it, and I have said to them that the only thing that would get me extremely upset and disturbed is if we did something that made nuclear power less safe, because my fears have to do with the safety of the waste."
Senator Warner and others have yet to release the text of proposed nuclear amendments. Boxer says that she would have no problem with additional funding to train workers in the nuclear power industry, to make plants safer or to have parts manufactured in America. "That kind of thing isn't a deal breaker for me," she says. But "there may be other amendments to 'streamline,' which I believe means [reducing] the time needed to make sure these plants are safe." That, she says, she would have to oppose.