Do they understand what they have signed? Plainly they do not. Governments such as ours, now ratifying the Paris agreement on climate change, haven’t the faintest idea what it means – either that or they have no intention of honouring it. For the first time we can see the numbers on which the agreement depends, and their logic is inescapable. Governments can either meet their international commitments or allow the prospecting and development of new…