Through the week, I was coming back to find my cycle after giving a short talk in Cambridge when I was stopped by a young woman called Maria. She was carrying a fold-over clipboard that proclaimed "Friends of the Earth" on the front; she had a Mediterranean accent, and eyes to match.
Maria asked me what I thought about the world. I requested that she rephrase the question so, after a short break, she asked me what I was doing that I could change to make a lesser impact on the world.
I thought for a couple of seconds. "You mean like turning the central heating down a bit?" I asked. "Or using the tumble-dryer less? Or taking the bus instead of driving, or not flying so much?" She nodded so excitedly that I felt guilty telling her that we couldn't afford to switch on the central heating unless there was ice outside; neither could we afford a car or to fly. Her dark eyes dulled a little.
Maria said she was there to raise awareness about the United Nations Climate Change Conference that was going to take place in Copenhagen in December. I thanked her and said I was already aware of it, and mentioned the lack of awareness about, at one end of the scale, the fire at the Littleport tyre recycling facility, near Ely in Cambridgeshire, that was spewing greenhouse gasses into the atmosphere like nothing on earth; and, on the other, the assertion that US president Barack Obama was so concerned about climate change that he was, in the words of Conservative peer Lord Christopher Monckton (right), willing to cede US sovereignty to a worldwide authority that resembled nothing so much as a government.
There is certainly a paragraph in the Copenhagen Draft that mentions a "dignity" penalty. Certainly the loss of dignity is poverty's most humiliating manifestation, but the clause in question seems to be nothing more than a stick to beat Western countries with, and bears no relation to the dignity of people in developing countries other than to turn it into a political football.
When I challenged Maria on whether the actions of humankind could have an effect on a climate that - as she agreed with me - has been changing for four billion years, she admitted (bravely, I thought) that she didn't know; but added that this was an opportunity to live in a way that took less of a toll on the earth.
On this point I both agreed with her wholeheartedly and parted company with her. It's probably a Celtic thing.
I agreed with her in that if we live more simply, we will have more money to give to those less fortunate than ourselves - but I'm disappointed to note that giving what we save to the poorer did not crop up in the Archbishop of Canterbury's speech on climate change.
Where I disagreed with her - and maybe I was being a bit previous as she hadn't mentioned population - was that an American economist, Jesse Ausubel, recently published an article in New Scientist saying that modern farming techniques could support a world population of 10 billion. I didn't actually go on to the United Nations Food and Agriculture Organisation (FAO) estimate in 1995 quoted by John Smeaton, Director of the Society for the Protection of Unborn Children, that agrictulture could support 30 billion people.
I suppose what was winding me up was that Jonathan Porritt, former head of Friends of the Earth, had signed off on the Optimum Population Trust's document Fewer Emitters, Less Emissions, Less Cost, which demands an 80% reduction in the global birth-rate. No matter where you are on the vexed spectrum of views about birth control, calling for an 80% reduction in the birth-rate isn't personal choice, it's genocide.
We went onto "Gaia", I have to admit, because I led the conversation there. Maria had never heard of it. So I took a deep breath and explained that according to the Gaian theory the earth was an organism with its own compensatory mechanisms. The reason I went there was because Maria had mentioned deforestation in the Amazon. I agreed this was a bad thing, and dropped in the suggestion of James Lovelock - originator of the Gaia hypothesis - that we bury nuclear waste in Amazonia in order to discourage people from settling there.
Maria's eyes blazed at this, and she said that we had no evidence about the effects of nuclear waste on people or animals over a lifgetime. I swallowed down a reply about Japan and about the lack of lifetime evidence about vaccines.
Just as we were about to go our separate ways she opened her clipboard and invited me to take out a direct debit in favour of Friends of the Earth. I thanked her but said I approach charities that I wish to donate to, not the other way round. She thanked me for listening to her then moved up the road. She was a deluded child but, I must admit, she had lovely eyes.