A confession: as crucially important as I realise the topic of global warming to be, I find that films, news articles and books generally hold little personal appeal. Partly that’s because I feel they’re preaching to the choir and I don’t need convincing. But also it’s perhaps because the reality of the fast-approaching tipping point is oppressively ever-present and the political and economic forces arraigned against taking the issue seriously are too enraging to worth risking too much of one’s mental health on.

This film’s director, actor-turned-filmmaker Damon Gameau (That Sugar Film), realises that many people feel similarly to this. As a result his documentary replaces the usual bells of doom with practical and calmly inventive solutions, resulting in a film that’s upbeat and visually lively, with digital effects subtly and inventively deployed.

Appearing on screen as the host, Gameau structures the film as a letter to his four-year-old daughter outlining various solutions for impending global catastrophe gleaned from fascinating interviews with ecologically-minded international experts in fields including transport, civic design, aquaculture, education and farming.

2040

None of the ideas explored here are purely...