On Friday, the US House of Representatives passed a groundbreaking bill that limits the amount of greenhouse gasses and takes a step forward in giving the US credibility in the global effort to reverse climate change.  In the months before December’s global climate change summit in Copenhagen, the US has finally taken actions towards addressing this issue.

At the heart of the legislation is a cap-and-trade system that sets a limit on overall emissions of heat-trapping gases while allowing utilities, manufacturers and other emitters to trade pollution permits, or allowances, among themselves. The final bill has a goal of reducing greenhouse gases in the United States to 17 percent below 2005 levels by 2020, and 83 percent by mid-century.  The cap would grow tighter over the years, pushing up the price of emissions and presumably driving industry to find cleaner ways of making energy.

The bill would grant a majority of the permits free in the early years of the program, to keep costs low. The Congressional Budget Office estimated that the average American household would pay an additional $175 a year in energy costs by 2020 as a result of the provision, while the poorest households would receive rebates that would lower their annual energy costs by $40.

The bill also sets a national standard of 20 percent for the production of renewable electricity by 2020, although a third of that could be met with efficiency measures rather than renewable energy sources like solar, wind and geothermal power.

It also devotes billions of dollars to new energy projects and subsidies for low-carbon agricultural practices, research on cleaner coal and electric vehicle development.

Al Gore, who shared a Nobel Peace Prize for his work on global warming, posted an appeal on his blog for passage of the legislation.  “This bill doesn’t solve every problem,” Mr. Gore said, “but passage today means that we build momentum for the debate coming up in the Senate and negotiations for the treaty talks in December which will put in place a global solution to the climate crisis. There is no backup plan.”