I remember going to the Green Party conference a few years back. The first chap I met was called “Freedom”. We handed out flyers – but then everyone handed them back after reading, so that we could re-use them. All in all, it was an eye-opening experience.

The Greens launched their manifesto yesterday and it was striking that they wanted to stress everything else they believe in as well as the environment: like higher spending, and getting even with the bankers. Perhaps that’s because the other parties have tried so hard to steal their clothes. These days it seems like there’s little difference over the ends of policy: all the main parties support a decarbonised economy bursting with new “green jobs”.

I think this is an artificial consensus – and one that won’t last long.

Over the next couple of years households will face a pincer movement of rising interest rates and sharply rising bills. The UK is going to have to spend about £500 billion on infrastructure, and much of that cost will be loaded onto our bills, fees and ticket prices. The cost of living will become a really big issue, and the cost of going green will be a big part of it.

We want to reduce emissions at the lowest possible cost. But the truth is that politicians have not been thinking enough about the cost-effectiveness of green policies. Politicians woke up to the environment pretty late in the day, and their goal has simply been to be seen doing as much “green stuff” as possible. As a result, policies have been cobbled together quickly and badly.

As a result the UK’s current climate change policy framework is a confused thicket of overlapping, complex and fiddly measures, some of which cancel each other out, and many of which need scrapping. If we carry on like this, going green will cost us tens of billions more than it should.