For me the Q&A at the St. Paul's meeting produced two striking moments.
The first was when Christiana Figueres answered the question: What is the most important thing to do about climate change? Her answer - Put a price on carbon. That is, we need a carbon tax that is high enough to change behaviour. Admirably clear and brief.
The second was when a member of the audience asked: Since modern capitalism system requires constant growth do we need to replace capitalism? The moment came when the audience applauded - the only question to be honoured with applause!
I also liked Tony Juniper's answer (my paraphrase): We don't have time to replace capitalism but we must reform it by breaking its obsession with economic growth.