Soon after Barack Obama was elected president, congressional climate change advocates set their sights on passing a cap-and-trade bill in time for him to bring a firm U.S.commitment on emissions reductions to this week's climate meeting in Copenhagen. "That was a situation we were hoping for,” says former Senate climate aide Tim Profeta. When Obama speaks on Friday, he is expected to say that the United States will cut emissions by 17% relative to 2005 by 2020—if Congress acts. His promise will be backed up by the provisions in the bill  the House of Representatives passed in June.
But the Senate has failed to act. The Kerry-Boxer legislation , which contains slightly more stringent provisions, has passed only one of the six committees  with jurisdiction. “We're trying to make the best of the situation," says Profeta, now director of the Nicholas School of Duke University in Durham, North Carolina.
Critics say that's an understatement. “Dead on arrival” is how Senator James Inhofe (R–OK) sees the legislation. So the big question is: Can Obama deliver on his pledges?
Needing 60 votes to win passage, supporters can now count on only about half that number as safe bets. That means they'll need to attract the rest from among a large pool of senators now on the fence .
Some Republicans, led by South Carolina's Senator Lindsey Graham (R–SC), and some coal-state Democrats, like Senator Robert Byrd (WV), say they could support cap and trade. But now that the Senate has moved its schedule for tackling climate legislation from this fall to next spring, advocates like Profeta face an increasingly unfriendly political atmosphere. "Every day closer to the  election it's going to be harder to do," he acknowledges. The president’s poll numbers may continue to slide.  Unemployment could remain around 10% or worse. According to pollsters, Americans don't care  about global warming. Even worse, in the last 18 months, their belief that it is happening at all has dropped . "It's going to be a tough environment to find 60 votes,” says Tom Gibson of the American Iron and Steel Institute.
Using her power as Speaker of the House of Representatives, Nancy Pelosi (D–CA) pushed through legislation, co-sponsored by Representatives Ed Markey (D–MA) and Henry Waxman (D–CA), that would cut carbon emissions by some 17% below 2005 levels by 2020. It passed by a margin of 219–212 . But history shows that the 60% majority required in the Senate will be much harder to obtain. In 2003, cap-and-trade legislation fell short by a margin of 43–55 . Two years later, the legislation did even worse in a 38–60 vote . In 2008, similar legislation that contained more favorable language for nuclear power fell 12 votes short  in a procedural vote that required 60 votes to pass—although six senators said they would've voted for the bill had they been present. “They're getting fewer and fewer votes," says Inhofe’s spokesperson.
To show other countries that such legislation has a chance, the president's team in Copenhagen is pointing to indications that long-time opponents of emissions reductions might now be willing to sign on. Late last week Senator Graham, flanked by Senators John Kerry (D–MA) and Joe Lieberman (ID–CT) introduced a framework  that would lower the emissions reductions in 2020 from 20%—the level in Boxer's bill—to 17%, add support for offshore drilling, and provide more money for nuclear power. Could Graham’s call for war on “perpetual carbon pollution” be a harbinger of Senate approval? Lou Leonard of the World Wildlife Fund said his participation was the "greatest indication that you can reach a 60-vote margin.”
There is also stirring among lawmakers from the nation's 20 coal states. Earlier this month, 92-year-old Byrd, who recently claimed the title of the country's longest serving legislator, wrote  that he wanted to "stay at the table" to make sure West Virginia was "part of any solution" to climate change. His behind-the-scenes maneuvering is likely to result in a bill that provides more money for clean-coal projects and assistance to industry than the House version, say insiders. But at least one knowledgeable analyst  thinks Byrd and coal state lawmakers like Senators Evan Bayh (D–IN) or Claire McCaskill (D–MO) need more incentives to support a bill on the floor of the Senate. The problem with each of these moves, of course, is that they risk alienating progressives like Bernie Sanders (I–VT). Speaking of what it take to win his support, Sanders told ScienceInsider  in an interview that “it depends on the nature of legislation, how weak it is.”
How does holding a vote after the Copenhagen meeting has ended change the equation in the Senate? In a statement, Senator Barbara Boxer (D–CA), who chairs the Environment and Public Works Committee, said: “If a political agreement is reached in Copenhagen that the United States is part of, it will help us move a climate change bill forward.” If that deal suggests that China and India will reduce their emissions, it might undermine the argument made in 1997 by 95 senators, who rejected the Kyoto treaty before it was signed , that the United States should not act without first obtaining the participation of the developing world.
But the details matter, too, says the Steel Institute’s Gibson. Those nations’ recent announcements of carbon intensity targets “are just business as usual," he says, and won't sway lawmakers. Early this week, top U.S. negotiator Todd Stern was pressing for more substantive concessions  from the two emerging superpowers. If he can't get them, Obama's promise to deliver cuts could alienate those still on the fence. “There will be more Democrats opposed to cap and trade after they see Obama set down a marker in Copenhagen,” predicts Inhofe's aide, Matt Dempsey.
There’s some question over whether the leaked e-mails scandal could damage the effort to get wary senators on board. Inhofe believes the scandal has “vindicated” him  and spells doom for climate legislation. But at least two Republicans—Senators Lamar Alexander (R–TN) and Lisa Murkowski (R–AL), told ScienceInsider in  interviews  that the e-mails have not shaken their confidence in the scientific evidence to support global warming. Indeed, Boxer told reporters at a press conference this week that the new push by foes to challenge on the fundamental facts of global warming will backfire since it will put “new attention on the science—and that's good.”
From a similarly counterintuitive perspective, could the 2010 election actually improve the chances of passing a climate bill next year? Profeta explains how that might work. "The Democrats already own this issue. There might be more political risk at this point with losing on climate change rather than passing a bill," says Profeta.
The biggest political challenge may be the Senate's packed schedule. The need to deal with health care, financial regulations, and a skyrocketing deficit could postpone a full debate on climate legislation until the summer, when almost everyone figures it would be too late. So as President Obama heads for Copenhagen, the question is whether his trip signals a willingness to make climate change a high-enough priority to cut through the legislative thicket and drive a bill home.