Arctic tundra changes are a dire warning for us all

Wildfires near Yellowknife in Canada’s Northwest Territories in 2023. Fires are turning the Arctic tundra into a net source of CO2 emissions. Photograph: Alamy

The shift of Arctic tundra and other carbon sinks to carbon sources (Arctic tundra is now emitting more carbon than it absorbs, US agency says, 10 December) reminds us that tipping points are largely irreversible on human timelines. We are involved in teams of specialists and students working to help global governments prepare for the decreasing stability of our planet, climate and societies. This needs fundamental changes while keeping them as steady as possible.

One of us co-authored, with Sir David King and 17 others, a dramatic but essential plan based on vast-scale ecosystem and climate restoration, and behavioural and systemic change.