In his Sept. 22 U.N. speech President Obama got it right: the battle to arrest calamitous climate change can be won only if each of us enlists, perseveres, and fights “for every inch of progress.”

It is, therefore, critical that the nation not embark on that battle with one hand tied behind our collective back.

During the long years of federal inaction, California and several other states forged ahead by enacting a range of policies aimed at restricting greenhouse gas (GHG) emissions. Now, in fits and starts, Congress is moving to create a meaningful federal program. To do that, the government should build upon and encourage state innovation. And yet, absent amendment, central features of the Waxman-Markey clean energy measure — which passed the House on June 26 — would undermine the climate benefits of state climate action. Now it is up to the Senate to avert that absurd result.

The problem is this: When no meaningful cap on emissions exists, initiatives that replace fossil fuel consumption with renewable energy generation or conservation work to reduce GHG emissions. But under the House’s cap-and-trade scheme, where polluters must surrender limited allowances to cover their emissions, reduced demand for fossil fuel frees up allowances that polluters can purchase and use. Consequently, additional pollution from expanded use of coal in Ohio, for example, could nullify the climate benefits of California’s GHG regulations.

In theory, under the House bill, individual states could require polluters within their borders to surrender additional allowances. But legal and political hurdles functionally will preclude states from using this mechanism to ensure that their programs yield truly additional emissions reductions. For one thing, surplus allowances resulting from reduced demand in one state may be realized or purchased by emitters in another, and so be out of reach.

Accordingly, under the proposed trading system, efforts such as tighter state renewable energy requirements or more-stringent state vehicle emissions standards may just make it cheaper for other emitters to spew additional GHG pollution.

There is a straightforward solution. Congress could direct EPA to set aside and retire surplus allowances resulting from state initiatives. That way, state climate action will continue to produce truly additional climate benefits — as contrasted with providing windfall subsidies to fossil fuel interests.

Safeguarding the ability of states to protect the environment is nothing new. Congress established in 1955 that air pollution prevention is the primary responsibility of states and local governments. Since that time, as California’s Jerry Brown and four other state attorneys general pointed out in an Aug. 31 letter to Senators Reid and Boxer, the federal government has set minimum standards with states and local governments free to do more.

President Obama previously recognized the essential principle last December, when he called for a “sustained, all-hands-on-deck effort” to harness “the power of wind and solar energy, to develop new technology, and to marshal the skill and dedication of scientists, of entrepreneurs, and of the American workforce.”  He intoned that “unless we act,” climate change will cause drought and famine abroad, devastating weather patterns, “terrible storms on our shores, and the disappearance of our coastline.” Stemming climate change and pursuing a clean energy economy, he concluded, is not a challenge for the federal government alone; rather, it is “a challenge for all of us.”

The President had it right then, as now. The Senate should appropriate the mandate that California established for itself in 2006 to reduce climate pollution to the maximum feasible extent. This requires, at minimum, that any new federal program build upon and not nullify state initiatives and related efforts. We can little afford to surrender an inch of progress.

Dan Galpern is an attorney with the Western Environmental Law Center.