It doesn't really make sense to me to assume that people _don't_ know this already. I mean, in a vox pop interview sense the average bloke on the street might

It doesn't really make sense to me to assume that people _don't_ know this already. I mean, in a vox pop interview sense the average bloke on the street might not. But I'd just figure - ok, the fuel to drive to Brighton and back is about £15 (and there's a ton of fuel duty on that), a steak is about £5-15 depending on quality, they're probably both about the same order of magnitude on carbon, and splitting hairs further than that doesn't make sense. If I knew that a steak had 5x the emissions of the drive or vice versa, what would I do differently? If the idea is that people should sit down and think "do I really need to go to Brighton" or "do I really need to eat that steak", then that's not about a numerical comparison, it's about adopting a lifestyle of ascetism. edit: looked it up, 1kg of beef is about 50-100kg co2 equiv so a 250g steak is about 12.5-25kg, most cars get about 100g/km so a Brighton round trip is approx 15kg equiv. With all of the uncertainty involved (probably should include production and maintenance on the car) they're about the same, which is intuitively reasonable.