World leaders 'have moral obligation to act' after UN climate report

Even half degree of extra warming will affect hundreds of millions of people, decimate corals and intensify heat extremes, report shows

• Full report: We have 12 years to limit climate change catastrophe, warns UN

World leaders have been told they have moral obligation to ramp up their action on the climate crisis in the wake of a new UN report that shows even half a degree of extra warming will affect hundreds of millions of people, decimate corals and intensify heat extremes.

But the muted response by Britain, Australia and other governments highlights the immense political challenges facing adoption of pathways to the relatively safe limit of 1.5C above pre-industrial temperatures outlined on Monday by the Intergovernmental Panel on Climate Change (IPCC).