SEATTLE - It was 21 years ago this month that Congress heard from a leading climate scientist that it should be doing something to curb greenhouse gas pollution. On Friday, the House may take the first major step in that direction.

Although some members of the Washington delegation claim they are still on the fence, the U.S. House votes Friday on the "American Clean Energy and Security Act" (HR 2454). It sets up a complicated cap-and-trade system that places a dollar value on carbon pollution, giving industry incentives to clean up or pay up. The only thing most observers agree on is that the bill is not perfect.

K. C. Golden, policy director for Seattle-based Climate Solutions, thinks the vote will say as much about politics as it does about reducing greenhouse gas pollution.

"That's what this bill is about. There's a lot of pages and a lot of complicated language, but at the end of the day, it's a referendum on whether they have the will to solve this problem."

The bill is 1,200 pages long. It has been stuffed with last-minute compromises, and there will be more if it goes to the Senate. However, Golden says, conservation groups and many business leaders will continue to back the legislation as long as it accomplishes some basic goals.

"Are they preserving that core commitment to reduce fossil fuel dependence on a clear schedule, with a real cap on climate pollution, and a really strong program for building our clean-energy economy? Those are the fundamentals that can't be compromised away."

Opponents of the bill believe it will raise energy costs, although that point is debated. Supporters say it will prompt greater investment in clean-energy technology and create jobs. In order for the bill to pass, 218 'yes' votes are needed.