Annual climate talks are a time for big announcements – new targets, new investments and partnerships. Politicians will often declare a new goal in the run-up to the conference, to show leadership or reassure others that they’re doing their part in the giant ‘I will if you will’ of global environmental diplomacy. What happens to those targets afterwards is less public. Sometimes that’s because they weren’t genuine in the first place. Sometimes it’s because they fizzle out or are overtaken by eve...