(CNN) -- The last few years have seen the beginnings of an energy revolution in the U.S. The coming of shale gas and now shale oil has transformed not just its energy outlook, but also the climate change debate. The game has changed: Energy independence, the goal first set by Nixon in the early 1970s, looks like being achievable, at least for the North American continent. The game that has changed has profound implications for energy and climate policy. To date it has been based upon two assumptions: The first is that fossil fuel prices would go ever upward as oil (and gas) production peaked and then declined. That, in turn, meant that energy policy should actively try to increase the security of the supply by increasing domestic energy production. The second was that climate change is best addressed by a top down international climate change agreement, and that within that framework, the U.S. should accept a cap on the amount of carbon it would release into the atmosphere.
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Dieter Helm: America's new abundance of energy is a game changer for the climate
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He says North America could achieve energy independence and is moving away from coal
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Without a real climate policy, U.S. carbon emissions have fallen to lowest level in decades
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Helm: Still needed is for the U.S., other nations to put a price on carbon emissions
So great are the potential oil and gas reserves that already @placeholder is producing most of its energy needs.