World leaders have departed the sprawling COP30 venue in the Amazonian city of Belém, Brazil, after hammering home the message that efforts to tackle climate change are moving too slowly.

Now the real work starts.

Over the next two weeks, negotiators from nearly 200 countries will thrash out the technical details on everything from how best to cut emissions to the structure of funds to help the poorest deal with the impacts of increasingly extreme weather.

Any final deal will mean somehow finding a consensus that can be tolerated by both the world’s biggest fossil fuel producers and …