Sydney Morning Herald: What started out here three years ago is now a global movement. Thanks to Sydney, Earth Hour is a force to be reckoned with, a people’s movement with influence, appeal and a simple aim. And in 2009 your collective switch-off will be seen around the world and, most importantly, in the halls of political power. Later this year, world leaders, Australian included, will gather in Copenhagen, Denmark, to set targets for greenhouse gas emissions post-2010. Against the backdrop of the …