Rolling Stone: This was supposed to be the transformative moment on global warming, the tipping point when America proved to the world that capitalism has a conscience, that we take the fate of the planet seriously. According to the script, Congress would pass a landmark bill committing the U.S. to deep cuts in carbon emissions. President Obama would then arrive in Copenhagen for the international climate summit, armed with the moral and political capital he needed to challenge the rest of the world to do …