Sydney Morning Herald: THEY range from the vulnerable, like low-lying Bangladesh, to the vast, such as the US; from the familiar – England, New Zealand – to the more obscure, such as the Commonwealth of the Northern Mariana Islands. Many are old hands, like Australia; some are first-timers, including Kosovo and Mongolia. What unites such a disparate group is concern about climate change. They have all signed on to participate in Earth Hour next Saturday. Now in its fourth year, Earth Hour has …