In case you’ve been wondering what happened at this weekend’s gathering of the G20 biggest-polluting countries, the answer is: pretty much nothing. Former British Prime Minister Tony Blair formally announced his goal to eke out a meaningful climate agreement, and declared, “We have reached the critical moment of decision on climate change. There are few, if any, genuine doubters left.” There is, however, plenty of disagreement over just how climate change should be tackled, and no breakthroughs were made this weekend.