Generally, we think of climate change as a gradual process: the more greenhouse gases that humans emit, the more the climate will change. But are there any “points of no return” that commit us to irreversible change?

Across vast swaths of the northern hemisphere’s higher reaches, frozen ground holds billions of tonnes of carbon.

Last summer, the Amazon rainforest was in the news again for all the wrong reasons. Deforestation rates are on the rise under the leadership of Brazilian President Jair Bolsonaro and 2019 brought the highest number of forest fires in almost a decade.

Between its east and west ice sheets and its peninsula, Antarctica holds enough ice to raise global sea levels by around 60m.