Not quite a month ago, the House passed Waxman-Markey (American Clean Energy & Security Act – ACES), landmark climate change legislation establishing a cap-and-trade system to regulate greenhouse gas emissions.

This wasn’t as easy as it looked. There was furious, dramatic finger-pointing, horse-trading, and more horse-trading. When the dust cleared, the bill had passed by an ominously close margin (219-212) – ominous especially because the current balance of power is 255 Democrats and 178 Republicans.

After a host of concessions to industry and agriculture, many environmentalists felt cheated. Other environmentalists pointed out that with a vote that close, legislation much stronger (i.e. more aggressive targets, more auctioning and less give-aways) would have been an extremely dangerous move, threatening to eliminate any short-term potential for progress on this front.

In an off-the-record conversation I had at the negotiations in Bonn, it became clear that certain high-level people negotiating for the US agree completely with this position. There’s little interest in tougher legislation that increases the risk of political failure. Instead, they’re for less aggressive, low political-risk immediate action, followed by years of strengthening work. It was explained to me that this is “the history of environmental legislation in the United States.” Pass it and then toughen up what you’ve got with lawsuits and more legislation.

Of course, the less short-term action we have on climate change, the tougher (and more expensive) it is to blunt the emissions trajectory and long-term impacts. Low political risk adds environmental risks. And these risks, with their attendant social and political risks, look scarier and scarier.

It’s an immensely difficult balancing act. The Senate fight promises to be fiendishly difficult as well, giving credence to the argument that we shouldn’t try for too much in this legislation, for fear of scuttling it entirely.

Yet this argument acts as if negotiations happen in a vacuum. Instead, they’re part and parcel of the political ecosystem of the US, which is anything but static. Politics is the art of the possible, and that changes from minute to minute.

Our future demands that we change what is possible.

This is going to take a fight.