4 ms·
That's true for many, yes, but it's only true in terms of time, not number of calories needed.
by awesomeideas 3y ago
That's true for many, yes, but it's only true in terms of time, not number of calories needed.
- indigobunting 3y agoThe energy conversion ratio gives it in calories. About 1.9% for beef. https://ourworldindata.org/meat-production#efficiency-of-meat-production https://ourworldindata.org/meat-production#efficiency-of-mea...
- Retric 3y agoI'm not seeing 1.9% and that sounds way off. US produces about 27 billion pounds of beef, roughly half of that weight comes from feedlots where they eat ~80% of feedlot calories comes from grains. There's a bunch of numbers tossed around but it's something like 60-70 billion pounds of grain to get those 27 billion pounds of beef.
- bumby 3y agoThis assumes humans could turn 100% of the feed into usable calories. Considering 1) the link defines feed to include grazing and 2) humans are 0% efficient at turning cellulose into calories, the quoted number probably doesn't mean what you think it means.
- Retric 3y agoWe have many ways of turning cellulose into useful calories. Fire being perhaps the oldest.
- deleted 3y ago[deleted]
- bumby 3y agoIf we could eat fire to sustain ourselves, then that would be a cogent point.
- Retric 3y agoEven if you’re just talking about biological calories rather than as a unit of energy, fire reduces energy expenditure to stay warm. Thus acting as a significant food supplement both historically and currently.
- bumby 3y agoThis is still a bit of a stretch to make a relevant point given the context of the discussion. I don’t think many are promoting getting rid of cattle to make room for biomass fuel.
- Retric 3y agoI've seen that argument made several times. EV's are great on land, boats have several options, but for mid to long range air travel biofules have a lot going for them. Unfortunately they need a lot of land. The underlying numbers seem reasonable with US airlines use ~10 billion gallons of fuel per year while the US produces ~15 billion gallons of ethanol being freed up by the rise in EV's. Globally things aren't as rosy, but freeing even 1/5 of the land devoted to grazing, alfalfa, and feed corn would go a long way. Reducing US beef consumption would have positive health impacts. So from a policy standpoint shifting the specific subsides seems like a good idea. Even if we can't get net zero the more we can cut quickly the longer we have to finish the job.
- bumby 3y agoI don’t think that premise holds. With the exception of sugar beets, crops are largely net negative in terms of energy production. You don’t create a more efficient system by adding layers of inefficiency.
- Retric 3y ago> You don’t create a more efficient system by adding layers of inefficiency. We care quite a lot about the form energy takes not just absolute quantities. $4 gets you ~200/kWh from solar enough to drive ~800 miles, or enough premium gas that to send an equivalent car less than 1/10th as far. Similarly, people happily pay 30c/kWh for 300kW fast charging because waiting around is it's own cost. In comparison with bio fuels, green hydrogen is wildly energy negative wasting ~80% of input energy and you need to completely redesign all passenger aircraft.
- bumby 3y agoYes. If the argument is about energy efficiency, I agree. Any system that is less than 100% efficient at turning calories into calories will result in, well, fewer calories. However, we shouldn't assume health and diet are simply a matter of calories as input. Even conceding that beef isn't a particularly good choice for human health given it's saturated fat content, I don't know that replacing beef in the diet with corn would necessarily result in better health outcomes.
- Retric 3y agoYou don't need to 1:1 plant corn for human consumption on that farmland due to increased efficiency. Options range from other crops, parks, leaving it fallow, solar, growing bio fuels, etc. Realistically we aren't going to replace beef any time soon, but who knows what happens in the future.