A draft of the Senate's version of a climate bill has been released. The official version is scheduled to be unveiled officially today in the Senate.

The move comes on the heels of President Obama's speech to the United Nations in which he called for action on climate change. A House climate bill passed back in May, but since then climate change has taken a back seat to health care reform. There's been some concern that no climate change legislation will be passed before a meeting in Copenhagen this December where world leaders are supposed to work out a new climate change treaty. With no law in hand, U.S. negotiators may find it hard to sell other countries on strict emissions reductions.

The draft bill tightens emissions caps somewhat compared to the House bill, calling for a 20 percent reduction in emissions by 2020 compared to 2005 levels, rather than a 17 percent reduction. It also contains sections devoted to reducing emissions specifically from transportation sources, as well as incentives for emissions reducing technology such as carbon capture and sequestration, nuclear power plants, and renewable energy.

But much work remains before the bill can become law. For example, some parts of the bill have only placeholder language, awaiting action from committees. Nevertheless, Senate Majority Leader Harry Reid (D-NV) has reportedly said that the bill is on track to be passed by the Senate before the Copenhagen meeting. That's not to say it will become law by then, of course, as it will still have to be reconciled with the House Bill.

A panel of nuclear-power experts may have inadvertently talked a key senator out of pushing for fast action on nuclear waste. On Monday, its members agreed that the United States has plenty of time to sort out good alternatives to storing waste at Yucca Mountain now that the Obama administration wants to take that potential repository off the table. A much more urgent issue, the experts said, is pushing forward the permitting and construction of new nuclear-power plants.

The panel, which took place at MIT, was moderated by Tom Carper, the United States senator from Delaware who is the chairman of the Senate Subcommittee on Clean Air and Nuclear Safety. The experts were from MIT and Harvard. They said that the current approach used to store nuclear waste at nuclear-power plants is safe and will be for decades, giving researchers and policy makers plenty of time to conduct research into new nuclear-reactor designs and new sites and methods for storing nuclear waste. "We don't need to rush," said Matthew Bunn, professor of public policy at Harvard University.

That might not be the best thing to tell a senator if you want funding. Near the conclusion of the discussion, Carper said that Congress has trouble taking action unless there is a crisis, and "when we talk about timelines that might go out 80 to 90 years, that's not a real crisis." He added that "the amount of time you allot to do a job is the amount of time you'll take to do a job . . . That may apply here as well."

The panelists do want funding, on the order of $500 million a year for nuclear-energy research, according to Ernest Moniz, a professor of physics at MIT. The research would need to include developing better reactor designs. For example, it's possible to reprocess nuclear waste to extract useful nuclear fuel, but according to the panel, the technology used to do this now is too expensive, could contribute to the spread of materials for nuclear weapons, and doesn't do much to reduce waste. In the future, better reactor designs could get 50 times as much energy from a pound of uranium as conventional nuclear plants get from a pound of uranium, and they could turn a nuclear waste dump into a source of fuel. "We do not know today if spent fuel is ultimately a waste, or is the nation's most important long-term energy resource," said Charles Forsberg, executive director of the Fuel Cycle Study at MIT.

But that's the potential future. "With the technologies that exist today, I believe it would be a costly mistake to move forward in deploying these types of reprocessing and recycling technologies," Bunn said.

Indeed, requiring reprocessing could be a major setback to the nuclear industry, which is starting to move toward building more plants after a decades-long hiatus. What's most important now is to get these first new plants built, mostly because of their potential to supply power without carbon dioxide emissions, Moniz said. "A move to reprocessing now is both unnecessary and in fact likely to be a major impediment towards that goal," he said.

The Senate version of the stimulus bill passed today. Now it's on to conference where legislators will try to work out differences between it and the House version of the bill.

One of the most significant differences between the bills, with regard to energy, has to do with provisions related to renewable energy tax credits. Renewable energy companies and those companies that finance them haven't been able to take advantage of tax credits lately, since they haven't been making enough money to have to pay any taxes. Renewable energy companies been suffering as a result, seeing financing dry up and projects stalled.

The House version of the bill contains a provision that would allow companies to get the money from those tax credits anyway--the money would take the form of a government grant. An early version of the Senate bill included a similar provision: a "carry-back" provision that allowed companies to take credits against taxes owed in previous years. But it was stripped from the final version.

There's a lot at stake here. Many renewable energy projects simply won't go forward without some sort of access to tax credits. The current tough times for the fledgling renewable energy industry could continue, but if the tax credits are made available, that could free up funding for new projects.

The Senate finance committee has a run-down of the other differences between the bills.