Guardian: We believe that the Paris agreement represents a historic opportunity for the world to tackle dangerous climate change. But that opportunity will only be realised if we follow up the good intentions of Paris with delivery in every country of the world. Paris was significant because it set out the ambition to keep global warming well below 2C, and ideally to 1.5C of warming, and it accepted that the world must get to net zero emissions in the second half of the century, in accordance with our scientific...