UN scientists say it's 'now or never' to limit global warming

UN scientists have unveiled a plan that they believe can limit the root causes of dangerous climate change.

A key UN body said in a report that there must be "rapid, deep and immediate" cuts in carbon dioxide emissions.

Global emissions of CO2 would need to peak within three years to stave off the worst impacts.

Even then, the world would also need technology to suck CO2 from the skies by mid-century.