After 25 years of denial and debate, Congress finally is drafting a climate change bill, responding to the largest outpouring of grass-roots activism since the civil rights movement.

The American Clean Energy and Security Act aspires to reduce greenhouse gas emissions by 20 percent of 2005 levels by 2020, 6 percent more than President Barack Obama’s goal.

The bill relies heavily on renewable energy, making carbon capture and sequestration technologies work on coal-burning plants, and developing a “smart grid” infrastructure to use greener energy efficiently.

The bill also would set important energy efficiency guidelines for new construction, the retrofitting of buildings, transportation and industry. It contains a carbon cap to limit greenhouse gas emissions and would help the economy and jobs transition during this green renaissance.

Rep. Edward Markey, D-Mass., a co-author of the bill, declared, “The time for delay, denial and inaction has come to an end.”

This is a historic moment. One would expect that the whole world would be in an expectant pause, with all eyes — animal and human — trained on Congress as our planet’s future hangs in the balance. In his testimony before Congress, former Vice President Al Gore likened the bill to the Marshall Plan in the 1940s and the civil rights legislation of the 1960s.

“Our country is at risk on three fronts,” Gore said. “The economic crisis is clear. Our national security remains at risk so long as we remain dangerously dependent on flows of foreign oil from reserves owned by sovereign states that are vulnerable to disruption. The rate of new discoveries, as you know, is falling even as demand elsewhere in the world is rising. Most importantly, of course, we are — along with the rest of humanity — facing the dire and growing threat of the climate crisis.”

The heart of the legislation — and the source of much debate about the bill — is the carbon cap and trade. The cap would set a legal limit for how much greenhouse gas pollution a company could dump into the atmosphere. The trade component would allow companies to trade pollution credits so that low polluters could sell their credits to bigger polluters.

Small businesses, such as farms, that produce little or no greenhouse gas emissions stand to profit from selling their credits to industry. Large polluters, such as oil refineries and coal generators, would be less profitable. Some key questions that must be worked out by Congress include how to allocate these carbon credits within industries and how to soften the transition so that workers in fossil-fuel jobs would not suffer even more.

Proponents of the bill point out that a cap on carbon pollution would curb climate change, spur investment and innovation in cleaner forms of energy, create tens of thousands of jobs for Americans, and transform the U.S. into the world’s clean-energy leader. Opponents of the bill worry about the economic impact and potential for higher energy costs.

“The question is can we do this in a way that boosts our economy and not hurts it, that creates jobs in America and not sends them overseas,” asked Rep. Tim Murphy, R-Pa.

The U.S. Environmental Protection Agency released its own study on the American Clean Energy and Security Act’s impact; it found that the bill would boost electricity prices by 22 percent by the year 2030. For the average U.S. household, however, the total energy bill would increase just 9 percent if part of the proceeds from auctioning the carbon credits were refunded to the public, as President Obama stipulates.

Under a similar emissions-trading system in Europe, carbon currently trades at about 26.45 euros a ton, or about $41. At that price, the value of the carbon credits would be about $220 billion in the first year alone. Louis Redshaw, the head of environmental markets at Barclays Capital, recently told The New York Times, “Carbon will be the world’s biggest commodity market, and it could become the world’s biggest market overall.” Perhaps the stock market would be replaced by the carbon market in a greener future.

Want to find out more? Go to www.1sky.org, www.RepowerAmerica.org and www.FocusTheNation.org.

Shawn can be reached at Shawn@zestoforange.com.