“It’s the science, stupid! Climate change is happening, humans are causing it, and action is urgent,” tweeted Connie Hedegaard, the EU's commissioner for climate action after Friday’s presentation in Stockholm of the most exhaustive and authoritative report on the state of climate science to date. She could have added that Portugal, along with Denmark and Sweden, are showing the way.

The final report of the International Panel on Climate Change (IPCC), compiled from 9,000 scientific studies by 800 scientists in many countries, has concluded there is now a 95% certainty that humans are the chief cause of global warming.