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Comment by lifeisstillgood | Hacker News Reader

Well that's a Holy Fuck moment for me.

I thought the parent here had made a off-by-orders of magnitude error - how can a liter of petrol (which itself is only a kg) produce 2.31kg of CO2 ... i mean work it out, all the carbon would have to attach to 2x oxygen ... ok that might just ... err ...

see this reference for a walk through of the calculation - http://ecoscore.be/en/info/ecoscore/co2

Every time I pour petrol into my tank I am basically pouring twice that weight of CO2 into the atmosphere.

I may be very dumb but I never thought if it like that before. I always assumed CO2 was a minor byproduct ... but like breathing.

oh dear.

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> like breathing

When you eat 1kg of peanut butter, if I've done my math right, you'll breathe out about 2.3kg of CO2. Dry cereal would be about 1.5kg. Most foods have a lot of water in them, though.

I would think you're unlikely to produce sufficient bile to metabolise an entire kilogram of peanut butter at once. Most likely you'd get really nasty, oily runs at best, and quite possibly throw up.

Darn and that looked like a pretty decent breakfast :-)

Yes, but the weight of the oxygen is in the atmosphere already. And for a bonus, all the hydrogen you burn removes O2 from the atmosphere in the form of water, reducing the weight of the atmosphere (and therefor the greenhouse effect of the atmosphere). How much the reduction of O2 from H burning offsets the transformation of O2 to CO2 is left as a problem for the reader. If anyone knows of a paper that discusses this effect, I'd love to read it.

most of the weight is oxygen, by definition CO2

Carbon Atomic Mass: 12.0107 amu Oxygen, about 16

so carbon itself is really just 27% of CO2 12 / (32 + 12)

so you're not pouring "twice the weight of CO2" of petro, that would be wrong. Its taking 73% of the weight from the air, and putting it back, plus a little more.

The point is I am taking a locked down "harmless" fluid and doubling its weight as "harmful" gas - the weight thing surprised me.

it was just a human way to look at it

Consider it this way. That entire liter turns to gas when burned, and in doing so it combines with O2 and other things in the air, resulting in the total weight of the liter + what it combined with entering the air.

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