ON A FROSTY winter’s afternoon in a coal town in the middle of the Hunter Valley, New South Wales, a motley group of Year Ten students slouch into a dimly lit room. They sit, sprawling almost on top of each other, and wait while their teacher ushers in the stragglers. Their friends take their turn finding a patch of floor. Some pick at the faded blue carpet. Others send rapid-fire text messages; later they confide to me that there’s gossip too important to wait until after class.

For the next hour, I have a conversation with them about climate change and what it means for their futures. First they stare at me. Then they ask questions. As they start to engage with the science, the ice is broken and they laugh at my admittedly lame jokes. They understand the seriousness of the situation.