WHEN film producer Simon Nasht approached me in 2011 about participating in I Can Change Your Mind, a documentary on climate change for ABC TV, I was just a little sceptical.

While I trusted Simon, this was the ABC, not renowned for its balance on this subject. And he wanted to pit me, a grey-haired, conservative, late-50s male, against an attractive, articulate, 20-something female. Was this a set-up? Simon was persuasive, and as I was about to leave Parliament I figured I had nothing to lose. And, importantly, it might be an opportunity for opinions not normally aired on the ABC to get a run.

So began an odyssey involving 10 cities in 21 days on a round-the-world expedition with four film crew, as well as trips to Perth, Heron Island and the Flinders Ranges, the whole time with a camera recording my every action and utterance.

Anna Rose - a climate activist whom I like and respect - deserves commendation for being part of it despite the pressure she was clearly under not to give a platform to dangerous and evil sceptics like me and those I took Anna to meet.

And, of course, Rose was a worthy opponent, and it was never going to be easy to change her mind. She has a strong conviction that mankind's use of fossil fuels will cause dangerous global warming, and brings great passion and eloquence to her advocacy.