Sydney Morning Herald: Five years is a very short time when it comes to measuring global warming. It's an age, however, in terms of assessing the politics of climate change. The political momentum for concerted global action looks much better today than it did five years ago when the Labor government of Julia Gillard started preparing for the ill-fated carbon tax. In recent months many nations have pledged to reduce emissions further than expected. Technology is evolving rapidly towards the goal of cleaner emissions....