Yesterday, the U.S. House of Representatives passed a bill that, if it becomes law, will change the face of America's factories, power sources, buildings, landscapes and working patterns.
I have been involved in a dozen pieces of landmark US environmental legislation over the last 30 years. None have been more important than this.
Let's start with the fact that the US has never had a coherent, comprehensive energy policy, and that the American Clean Energy and Security Act (ACES) would provide one. The bill sets out a long-term road map to shift the world's biggest economy on to a low carbon path. WRI's analysis shows that it is the strongest climate bill ever to come before Congress, setting mandatory caps on sectors responsible for 87% of US greenhouse gas emissions including electric power, oil and gas, and heavy industry.
By putting a price on greenhouse gas emissions, ACES sends a vital message to businesses and investors that markets for low-carbon products and services are the future. The US is home to the most entrepreneurial and innovative private sector in the world. With this signal we can develop the technology to keep global warming within manageable limits.
Almost as important are the bill's international implications. With the months to the UN Copenhagen summit counting down, the world urgently awaits US leadership. The concrete greenhouse gas targets and additional carbon-cutting measures in this bill, and its provisions to help finance developing country adaptation to climate change, send a strong signal that the US is serious about negotiating a new global deal in Denmark this December.
But despite yesterday's victory, ACES still faces an uncertain future in the U.S. Senate. If the Senate defeats the bill, it may be years before Congress returns to the subject. Meanwhile, the Copenhagen negotiations would collapse. Other nations would take Congress's failure to limit US emissions as a signal that the world economy will continue to pursue business-as-usual energy policies. And the planet continues to heat at an accelerating and dangerous rate.
Like many, I would like to see deeper cuts. But what is most important is to start changing the trajectory of the greenhouse gas-generating juggernaut that is the US economy. And the alternative is not a stronger bill, it is no bill.
An earlier version of this article originally appeared in The Guardian.