The Two Views of COP21
Robert Stavins thinks it is a Good Foundation for Meaningful Progress and provides a good analysis of his reasons.
On the other hand both Bill McKibben and Naomi Klein are not impressed, although I seem to recall seeing reports they had each decided that before the final agreement was announced. Klein has a really nice turn of phrase
“It’s like going: ‘I acknowledge that I will die of a heart attack if I don’t radically lower my blood pressure. I acknowledge that in order to do that I need to cut out alcohol, fatty foods and exercise every day. I therefore will exercise once a week, eat four hamburgers instead of five and only binge drink twice a week and you have to call me a hero because I’ve never done this before and you have no idea how lazy I used to be.'”
UPDATE David Roberts on VOX explains why the Paris treaty is about as good as the UN can manage – which may or may not be enough to start the process of change – which depends on the nations not UNO