As Confucius taught us, there are three methods to gaining wisdom. "Reflection, which is the noblest. Imitation, which is in essence perhaps the easiest. Experience, which is the bitterest." The climate agreement, approved by nearly 200 states at the United Nations climate change conference in Paris last year, embodies these three elements precisely.

First, in the run-up to the conference, every country was invited to "reflect" on its contribution to cut greenhouse gas emissions. Also, a five-year cycle of reflection to measure progress was agreed.

Second, countries are learning from and building on each other. Leading countries developing the right policies and leading companies developing new technologies are closely watched and "imitated" by others. These collective efforts must eventually add up to limiting the global average temperature rise to 1.5 C to 2 C, as agreed in Paris.