“If things are that bad,” demanded the medical student at the back of the room, “why aren’t you doing more? I’m only 19, and it’s my generation that is going to be left to confront climate change.”

Just for a moment the room went quiet. The middle aged experts at the Chatham House conference on global health security had spent the whole morning summarising data about the daunting pace of climate change, its increasing impact on health, and the need to mitigate its effects on the world’s most vulnerable people. What more was the student expecting them to do? Chain themselves to railings? Lie down on the runway at Heathrow?

They did not ask, and she did not elaborate, although it would have been an opportunity to mention that this is an issue where some doctors have gone into activist mode and are leading a global campaign to persuade governments to reduce carbon emissions and help the world’s poorest populations adapt to the effects of global warming (www.climateandhealth.org). …