In the first programme Greta travels through North America on her way to a UN climate conference in Chile. To understand the impact of climate change she stops at three key locations that reveal how the planet is changing. In the Canadian Rockies she learns how a small change in temperature has allowed an insect infestation to kill nearly half the trees in one of its most famous national parks. She visits a glacier that’s melting faster than models predict and discovers the cause is partly due to soot from forest fires falling on it.

Greta sets off to the annual World Economic Forum in Davos, Switzerland. She also travels to the UK to see the prototype of a technology that aims to lower emissions from industry and meets with a figure who’s been an inspiration to her, Sir David Attenborough.