For the last eight years I have limited my flying, with just one flight in that period and none in the last six years.

I am convinced that the necessary changes are primarily political, economic, and cultural, but there are complex links between these social structures and personal behaviour and beliefs, so avoiding flying is both a personal discipline and a conversation starter (or sometimes, part of a useful conversation ender when a hostile audience member wants to accuse me of hypocrisy because I haven’t talked about personal lifestyle changes). I don’t mention it often, but when it comes up naturally, it has a powerful impact, underlining the scale of societal changes necessary.

Due to my commitment, I have missed funerals and weddings of friends and family. I have missed conferences and turned down speaking opportunities (I try to connect those inviting me to someone in their city who can do a similar presentation). It has brought me into tension with people I love. But I believe it has also been part of giving my words greater impact because my life is one step closer to matching what I say it ought to be.