New Ideas for a New Year: solving the environmental crisis is going to take new ways of thinking. This month, the team explores two 21st Century ideas which approach the problem and finds out about Doughnut Economics from Geraint Davies and Diner Ismail of the Cambridge Doughnut Economic Action Group and talk to both Sarah Allan, who helped lead the organisation of the UK's first Climate Assembly, and Liz Roman, who was part of it.