In the programme we featured a recycling project in Mali. I first went there about eight years ago, and it was a complete revelation to me. It was incredibly exciting; I found the place packed with passionate, beautiful, optimistic people who despite almost unimaginable problems have not lost a sense of who they are and how to relate to each other.
The scheme we featured is one which has evolved through necessity. They really do make waste metals into ploughshares. It also raises big issues for us. Whenever I get worried about my own levels of waste, I always go back in my own mind to places like it - everything seems to be precious and people wouldn't dream of throwing away something they could recycle.
It's a strange vision of the future - places like it are not backward, actually they're modern. And even though it's not a particularly palatable lesson, it's one we've got to learn as a society. You can hear more from our trip to Mali here.
In the programme we also talked a bit about the changing nature of the music industry. Chris Morrison, manager of Blur and Gorillaz, reflected on how technology and attitudes have changed since the early 70s when he was managing Thin Lizzy.
And we also thought a bit about the nature of celebrity. I strongly believe we need to dismantle significant parts of our culture and re-examine them. I think the celebrity thing sends all the wrong messages - creating a mindset that you can get something for nothing and that it's easy to acquire status and fame.
X-Factor would be the first thing I'd tackle. But never Radio Four.
My entire life has been supplemented by Radio Four, from hearing my mum tuning in to the Archers to my anxious middle-aged sleeplessness being calmed by night-time radio. I am Radio Four and Radio Four is me. And when the time comes, I want it piped into my coffin.