They did so by confronting climate change realities and committing their cities, organisations, states and companies to more sustainable futures.
So despite the monopoly of fossil-fuel political power, and the failure of governments to move quickly, critical incremental change is happening. China alone will have 900 gigawatts of renewable energy online by 2010. And if the resurrection of electric vehicles is any indication, change is happening in all corners - almost every major car company has electric cars hitting the road in the coming two years. Whether all of this will save our skins is a question for fatalists.
Keeping Earth inhabitable is the right fight. As our favourite Copenhagen street sign proclaimed: "There is No Planet B".