There are not many political messages that can slip through a closed window or a locked door, but that’s just what happened last week in Australia’s biggest city. Climate change didn’t just come knocking; it slithered in under every crack, filling houses and offices across Sydney with the acrid smell of burning forests. The Sydney Opera House, whose white-tiled sails normally sparkle in the sunlight, was seen through a haze of smoke. Asthmatics were advised against exercising. Schoolchildren were kept in their classrooms, away from the smoke-filled playground. And politicians, especially from the ruling conservative coalition, issued instructions that it was inappropriate to discuss climate change while the fires were actively being fought. How could climate change not be discussed? […]