“I HAD low expectations,” said one environmentalist at the conclusion of the UN climate change conference in the Mexican resort of Cancun at the weekend, “and they’ve been fully met.” It’s a reaction that’s been widely shared over the last few days. Enough had been achieved to save the UN process, observed Greenpeace, but not enough to save the planet. Yet the downbeat assessment stood in stark contrast to the cheering, foot-stomping euphoria of the delegates themselves as the chair of the conference, the Mexican Foreign Minister Patricia Espinosa, brought down her gavel on a wide-ranging set of agreements in the early hours of last Saturday morning.

Why the difference in reaction? Well for the delegates it was no doubt relief that, at the very last minute (in fact, beyond it – the conference was due to close on Friday), consensus had been snatched from the jaws of the failure that looked much more likely until just hours earlier. But it also represented a fundamental difference in understanding of the political economy of climate change – for Cancun has performed the remarkable feat of simultaneously changing nothing, and changing a great deal…