Paris climate summit: Do UN climate change treaties ever work?

The UN says that an agreement at the Paris climate summit will build on the success of the previous treaty, known as the Kyoto Protocol. Others say Kyoto was a failure, and that the same problems will plague any agreement in Paris.

Developing countries were not required to make cuts under the Kyoto Protocol. A number of industrialised countries – including the US, then the biggest polluter – didn’t sign up and Canada withdrew in 2011.