Environmental psychologist Dr Wouter Poortinga shares how the 5p plastic bag tax in the UK reduced consumption between 70 and 90 percent almost overnight. He discusses how, with a little bit of prompting, habits can change and how we need a plan to stop wasting take-away coffee cups.Recorded: 8 February 2017Interviewer: Steve GrimwadeProducers: Dr Andi Horvath and Chris HatzisAudio Engineering: Gavin NebauerEditor: Chris HatzisBanner image: Claudia Hooper and Lep Beljac