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> The human body is very efficient. Uhh, you are not using the right metric. Yes, humans take calories, and convert it to energy at a rate of 25%. But you ar
by stale2002 9y ago
> The human body is very efficient.
Uhh, you are not using the right metric.
Yes, humans take calories, and convert it to energy at a rate of 25%. But you aren't eating coal and turning it into energy.
The ways that humans turn sunlight into energy is that the sunlight hits plants, which gets harvested by humans, which gets fed to cows, and then get harvested, prepared, and transported to stores, and THEN it is consumed by humans.
I sincerely doubt humans are more efficient than cars, on a per energy basis.
- IgorPartola 9y agoThis. Last estimate I saw said that you consume 10KW by just sitting there and breathing doing nothing. Because agriculture to feed you takes so much damn energy. Really we are talking about the difference in that roughly 10KW figure between a driver and a cyclist.
- dTal 9y agoYou are quite correct. There are some mitigating circumstances though. The biggie is that all of this food is, in theory, carbon neutral; plants require CO2 to grow. While obviously this does not apply to the tractors, trucks, cargo ships etc in the rest of the preparation chain, that goes for fossil fuels as well - and chances are the fossil fuels have had to come farther and undergo even more processing. Nor are the emissions of the supply chain intrinsic to the fuel: we could theoretically replace all those tractors with electric ones powered by solar etc... The other factor is that we can exert a great deal of personal agency over the emissions content of the food we eat. Cows, which you mention, are particularly bad because, although carbon-neutral, they effectively turn CO2 into methane which is a far more potent greenhouse gas. But we don't have to eat cows. Or food from the other side of the world. You can even grow your own food if you really want. So human-powering things reclaims personal responsibility.