Five years ago I woke in the middle of the night and wrote a letter to myself about climate change. I’ve never shared it with anyone. I didn’t think other people would relate to how I was feeling. But now that articles about the end of civilisation are going viral, I can see I’m not the only one who’s been up late at night, shuddering with this awful premonition.

The letter I wrote to myself is called ‘living in the lag’, and it starts like this. ‘The world around you right now no longer exists. The conditions that created it have already changed and the society you know remains the same only due to inertia. Recognise this lag. Plan according not to what you see around you today — a reality established by causes decades or centuries before — but according to the emerging conditions that will dictate the future.’

All abstract stuff, so let me draw out the lessons.