With all the attention on health care, it's easy to forget another major bill is working its way through Congress.

But the climate change bill will have its day soon enough.

Once the health care debate ends, the cap and trade legislation will be the biggest fight in town. Since the House already passed its version (HR 2454 ), all eyes will once again be on the Senate (S 1733 ).

Given the contentious nature of climate change, it will likely draw out activists on both sides of the issue, stir up would-be Republican presidential contenders and inspire a flurry of television ads from environmentalists and industry groups.

With the help of CQ reporter Coral Davenport, we pulled together six things you should know about where the bill stands today:

* Three senators are leading the fight. Sen. John Kerry, now the senior Democrat from Massachusetts, is getting new attention for his role in pushing the climate change bill. He's joined by Sen. Joe Lieberman, a Connecticut independent who co-sponsored the last attempt. More importantly, Republican Sen. Lindsey Graham of South Carolina is working for a version of the bill that members of his party could support.

* The Senate probably won't vote until 2010. Democratic leaders say they won't get the bill through any more major committees before the end of the year, meaning it won't be on the Senate floor until early 2010. The ongoing debate over a health care overhaul is partially responsible for the delay, as is the complexity of getting 60 senators to overcome a potential filibuster.

* A key Democrat now supports the bill. Sen. Max Baucus, a Montana Democrat who heads the Finance Committee, said last week that he would support getting a cap-and-trade bill through the Senate relatively soon. Baucus is important because his committee has jurisdiction over several contentious parts of the bill. His review of the health care overhaul contributed to a significant delay earlier this year.

* The vote will divide more along regional lines than partisan ones. Some areas of the country may be harder hit by climate change, while others fear cap and trade could hurt local oil and gas producers. Democrats fear they'll lose the support of Sens. Robert Byrd, Mary Landrieu and Ben Nelson, but they hope to pick up Republican Sens. Lindsey Graham, John McCain, Lisa Murkowski, Judd Gregg, Susan Collins and Olympia Snowe in order to reach a filibuster-proof 60 votes.

* The White House is threatening an end-run. The Environmental Protection Agency has asked the president to give it the authority to regulate carbon dioxide and other greenhouse gases under the Clean Air Act, regardless of whether Congress acts. That could open Obama up to criticism and it would mean fewer sweeteners for the oil and coal industries than a Congressional bill, so it's generally considered a last resort by both sides.

* Progress on the bill will help the U.S. negotiate with foreign countries. At the United Nations-led conference on climate change in Copenhagen next month, U.S. representatives will point to committee hearings and pledges of support for the bill to persuade China and India to agree to cut their own emissions. If the bill becomes a law, the U.S. could then push for an actual treaty sometime next year.

For more information, see our rundown of the cap and trade bill.

Coral Davenport covers environmental issues for Congressional Quarterly.