World leaders have been told they must take greater action on the climate crisis, following the release of the new Intergovernmental Panel on Climate Change (IPCC) report that shows even half a degree Celsius of extra warming will affect every nation, whether it is large or small, rich or poor.

But there are immense challenges facing the adoption of pathways to remain below the relatively safe limit of 1.5 deg C above pre-industrial temperatures. The urgency stems from the fact that decades of data shows that a long-term build-up of greenhouse gases in the atmosphere is trapping heat and warming up lands, oceans and the atmosphere.