(Reuters) - U.S. President Barack Obama and his fellow Democrats in Congress have placed a high priority on enacting a climate change bill that would reduce emissions of carbon dioxide and other gases blamed for global warming.
Here are the major legislative and political factors that will determine its fate:
* In June, the House of Representatives narrowly passed a bill calling for a 17 percent cut in smokestack emissions by 2020, from 2005 levels. By 2050, that pollution would have to be reduced by 83 percent.
* Senate Democrats are crafting a very similar bill. The Senate Environment and Public Works Committee, chaired by Barbara Boxer of California, wants to approve the legislation in coming weeks.
* Various other Senate committees also will review the measure, including the Finance Committee, which oversees the collection of revenues and trade restrictions. The Senate Agriculture panel will look at how farmers are treated. Senate Foreign Relations Committee Chairman John Kerry has joined with Boxer in pushing the bill, which will have an impact on other industrialized and developing countries.
* Once these and other committees suggest their changes to the legislation, Senate Majority Leader Harry Reid of Nevada will have to decide which provisions he wants and which he doesn’t want in a unified bill.
* If there’s time this year, the Senate would try to pass a bill before December’s international meeting in Copenhagen, which aims to set new global goals on climate change.
* If the Senate runs out of time, it doesn’t have to start from scratch. It could convene in January, picking up where it left off and Reid could schedule a floor debate and vote sometime during the year.
* There are 100 seats in the Senate. But without 60 votes, legislation, especially controversial bills, can be blocked by a minority of senators using procedural tactics.
* Democrats control 60 seats, but there are many moderates in the party who worry that mandating the use of more alternative energies, at the expense mainly of coal and oil, will hurt manufacturing jobs and raise consumer prices.
* Some of the moderate Democrats would not be needed to pass a bill, if some of the 40 Republicans can be brought on board. But so far, even some of the most moderate Republicans, such as Olympia Snowe from Maine, have not yet indicated they’ll vote for a climate bill.
* Climate change legislation opponents might argue that if it doesn’t pass this year, Democrats will have an even harder time enacting one next year in the run-up to the November, 2010 congressional elections. But history shows that most of the major environmental laws of the past few decades actually were enacted during election years.
* Progress at an international climate change meeting in Copenhagen in December could put pressure on the Senate to act next year if a bill falters this year.
* An improving U.S. economy in 2010 also could encourage undecided lawmakers to support a bill, especially if they can argue the U.S. employment picture was improving and a climate bill would create even more jobs.
* Conversely, if the U.S. economy is not in a recovery, voting for a climate bill during an election year could be even more difficult for senators from Midwestern and southern states, where dirty-burning coal is produced and widely used.
* Last week’s G20 meeting of major economic powers failed to reach agreement on how much money developing countries will contribute to poorer nations to help them reduce emissions. They’ll keep trying this month and next, but a failure by December could further undercut international climate change efforts, and thus the U.S. Senate’s work.
Reporting by Richard Cowan, editing by Anthony Boadle