Klein tells how she wants him to bear witness. “Just in case, amid the coral that is still alive, he can find something beautiful to connect with, something he can carry with him as he navigates life on a warmer, harsher planet than the one I grew up on. Because climate change is already here – and kids are on the frontlines.”

In an accompanying article, she tells why she was persuaded to join the Guardian on the project, and why she decided to include her son. “I started thinking: maybe this was a chance to get at aspects of climate disruption that scientific reports and political arguments just can’t convey. Perhaps it could communicate, in a visceral way, the intergenerational theft at the heart of this crisis.”

For the past eight years Klein has been writing and speaking about climate change around the clock and she is visiting Australia to to receive the Sydney peace prize.

The film follows Guardian Australia’s Reef on the brink series in June, which presented new data and exclusive photographs mapping the increase in water temperatures causing the mass coral bleaching on the Great Barrier Reef.