Read the full story from the BBC.
Is it remotely feasible to remove 12 billion tonnes of carbon dioxide from the air? Every year. For decades to come.
That’s the challenge posed by the latest conclusions of the UN’s climate science panel.
It says that only by pulling this heat-trapping gas out of the atmosphere can we avoid dangerous climate change.
But according to one leading researcher, there’s a bit of a hitch: “We haven’t a clue how to do it”.
The problem is that scientists reckon that even if the world manages to cut emissions of the gas, it will no longer be enough to avoid the worst impacts.
We’ve got to go a step further, they say, and find ways of doing something never attempted before: get rid of the gas that’s already out there. And get started on it as soon as possible. On an unimaginable scale.