COP21: One step forward, a mile to go

At the Paris climate conference last December, all the world's countries were able to reach a consensus about a matter of profound importance. They agreed that climate change needs to be halted and that every country must play a role in halting it. Why were countries able to reach a consensus? One reason, of course, is that all countries recognize the threat posed by climate change. But another reason is that, under the rules of the fi rst climate treaty, adopted in Rio in 1992 (the United Nations Framework Convention on Climate Change, or UNFCCC) decisions by the parties must be agreed by consensus. As the new agreement was being negotiated under these same rules, opposition by any country could have sunk the effort â this is what happened in Copenhagen in 2009 at the previous make-or-break climate meeting. All countries agreed after this that they had no alternative but to try again.