[danieltillett]

Does anyone know how much carbon is released to grow the extra food that you use cycling verses what you would use driving? Food production is very energy intensive and the human body very inefficient.

You can’t effect the amount of carbon released by adopting a low carbon lifestyle when the price of fossil fuels is above the cost of production. All reducing demand at the margin does is lower the marginal price causing an increase in consumption elsewhere in the economy.

[btrettel]

https://bicycleuniverse.info/bicycling-wastes-gas/

According to this a "typical" omnivore cyclist produces about 3 times less carbon than a "typical" driver. Vegan and vegetarian are about 4 times less. You can play around with the numbers in the calculator. I think this guy's probably biased towards veganism, but this is what I've seen.

I haven't seen a comparison with motorcycles or electric vehicles, or a comparison that took into account the embodied energy of the vehicles.

Edit: This calculator also assumes equal trip distances between modes of transportation, which is not realistic in my experience. Cyclists tend to have shorter trips. So that's another factor to consider.

> You can’t effect the amount of carbon released by adopting a low carbon lifestyle when the price of fossil fuels is above the cost of production. All reducing demand at the margin does is lower the marginal price causing an increase in consumption elsewhere in the economy.

If that's true, then I guess the goal is to slowly reduce the price. Perhaps cycling is ineffective in terms of carbon emissions. This is okay for me as I find either the cost or physical fitness benefits convincing in isolation.

[danieltillett]

Thanks - as I suspected it is really complex and very dependent on the assumptions.

I would love to cycle more, but I fear for my life riding on roads with traffic. I have seen far too many killed cyclist with my own eyes - in fact when I think about the only dead people I have seen are cyclists and motorcyclists.

[plorg]

The obvious difference is that a human on a bicycle is moving on the order of 10 times less mass than a human in a car. Like my sibling post notes, it could be different for, e.g, a motorcycle, but a cyclist also produces about 0% of the SOx, NOx, or particulate emmissions of those vehicles, whichever is a somewhat different conversation.

[danieltillett]

Well those particulates and gases are still produced in the production and transport of food. If you eat more food then more will have to be grown and transported.

[DanBC]

How many calories do you think two hours of cycling uses?

It's not much, and it's comfortably within what most people are eating already.

[danieltillett]

Maybe, but without some good data it is hard to say. I do know that us sloth-like generation eat far less than our ancestors.

[AstralStorm]

The extra movement that increases the resting metabolic rate would cost about 500 kcal combined with the load. Estimating for an hour of cycling daily.

This means about one extra meal to match which would actually cut into waste if it is done smart. Or perhaps you do not even have to adjust anything. (obesity is a thing)

[flukus]

Some of that food could be a carbon sink, depending on how it's grown, how it's transported and where it ends up. With the later it might even get a second life generating electricity.

[danieltillett]

Yes this is all true, but it makes it really hard to know what the carbon footprint actually is.

[singularity2001]

> the human body very inefficient

the human brain uses 20 watts and has more computational power than the best supercomputer, so you should be careful.

how far does a car go with 1 yogurt?

[AstralStorm]

Suppose it is a sweet yogurt and has 300 kcal in a package (1 kcal/ml) and we use bioethanol in a car, it is a match 1:1. Ignoring conversion losses and metabolism, a car taking 6l/100km and a trained human on foot would go some 12 km on this. (human on a bicycle is comparable to a specially designed ecocar)

A fully manned car (5 persons) or a loaded truck wins by a good margin even over a tandem or cargo bike. A bus or truck even more so.

The main difference is in initial material costs, refining metals is expensive. The problem remains how to cleanly burn and source bioethanol.

[singularity2001]

> how far does a car go with 1 yogurt?

wow, didn't expect actual coaster approximation