We’ve just bitten the bullet and bought a new family car. Having three kids needing car seats/boosters limited our options massively – few 5 seaters have enough space across the back seat, so, after much head-scratching, we settled on a Ford S-Max 7 seater (above).

Despite being a much bigger beast, the S-Max has slightly lower CO2 emissions per km than our old VW Golf (138 g/km compared to 143 g/km). That salved our carbon consciences somewhat (along with the fact our annual mileage is low and much of what we do do offsets flying).

One option we didn’t consider was a spacious SUV – for obvious reasons.

Hold on. For ‘obvious reasons’? What are those?

Er, that SUVs destroy the planet with their gas-guzzling and their carbon-belching?

Do they? A Nissan X-Trail SUV emits 129-138 g CO2/km depending on whether you go 2WD or 4WD. The lower end of that is not far off the average for the UK and better than our S-Max.

If I’m honest, I didn’t check whether the received wisdom on SUVs was correct until it was too late. If I’m really, really honest, the more powerful motive was that I didn’t want to be seen to be driving an SUV no matter what.

Over the summer, I’ve been reading Thinking, Fast and Slow, Nobel prize-winning psychologist Daniel Kahneman’s brilliant treatise on decision making. The central premise is that we generally make decisions on intuition based on previous experience, rather than careful, objective analysis. And, it seems, the ‘SUV = evil’ meme was more deeply embedded in my mind than I’d ever realised.

I’ll be musing more on Kahneman over the next few weeks, but, in short, every sustainability practitioner should read it.