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Comment by dheera | Hacker News Reader

See my comment above with the numbers.

2000 kcal worth of food takes somewhere in the range of 6 kg (for vegetables) to 72 kg (for beef) of CO2 emissions to farm.

If you assume a gas car needs 35000 kcal to make the same journey it's about 10 kg of CO2 emissions.

You're making a kcal-to-kcal comparison, which is apples-to-oranges in terms of climate change. Climate change doesn't care about kcal, it's greenhouse gases like CO2 that do matter.

I know internet forum people are going to come back with a retort about how drivers also eat, but the fact is that cyclists do need to eat more than drivers to make the same journey, and the math puts the answer somewhere in the middle, you need to do the interpolation.

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Your numbers are absolute nonsense. You excluded the CO2 to extract the oil and refine it into petrol/diesel. Nobody eats 2000kcal of beef: that's 6 whole burgers!

On top of that, your numbers assume that drivers don't eat, which is self-evidently not true!

> You excluded the CO2 to extract the oil

This is miniscule compared to the amount emitted by burning it. It sort of has to be, or the industry wouldn't exist.

Congratulations, you're now deliberately fishing at the opposite and and nitpicking at the opposite end just to argue, at this point, when you could be looking at the entire pond.

Of course nobody eats 2000kcal of beef, I never said that. I was providing an extremum of all-brassica and all-beef so that you can interpolate somewhere between them, but evidently you're more interested in taking the endpoints and call it nonsense instead of doing the interpolation.

So go ahead and assume drivers eat. Bikers eat more. Again, do the interpolation. You get some data, you do the math, then argue. You will still find that it's within the same order of magnitude. CO2 from food production is a thing, and it's hugely variable depending on diet, that's the point.

> So go ahead and assume drivers eat. Bikers eat more.

Not that much more, and you're being disgustingly disingenuous by just grabbing the mid-point. To get 2000kcal, you're going to be eating more rice, potatoes and raw sugar i.e. carb-dense foods to fuel the ride. That's more like 2kg of CO2, so vastly below the 10kg of CO2.

I can safely exclude the beef, pork, etc. because that's food I'd eat "outside" of fuelling the ride. To spell it out for you: I won't eat more meat because I rode 65 miles, I'd eat more potatoes and cane sugar. Thus, that's what we measure in terms of excess CO2 produced vs just sitting on my couch.

Also, I'm being very generous to cars here. Most don't come close to achieving 65mpg, and certainly not on the route I measured with the steep climbs it involves.

I have actually eaten eight 1/8 lb hamburgers during a 100 mile bike ride — once. It was a whimsical tour of a local fast food chain.

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