Sydney Morning Herald: The latest report on climate change by the economics professor Ross Garnaut is the most disheartening government report I’ve read. It tells us how hugely destructive climate change is likely to be, but doubts that the world’s governments will be able to agree on effective action to halt it. Now you know why economics is called the dismal science. Garnaut quotes an authoritative American study of the consequences if nothing is done to fight climate change and average temperatures rise …