[Retric]

I'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]

I 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]

> 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]

>We care quite a lot about the form energy takes not just absolute quantities.

Yes, I've already mentioned this:

>However, we shouldn't assume health and diet are simply a matter of calories as input.

In the context of the discussion, it's an error IMO to compare energy as if they are interchangable. People aren't just consuming beef just for it's caloric value. The "form" of energy (protein & fat) is an important consideration too.

>In comparison with bio fuels, green hydrogen

The constant digression of a topic focused on nutrition into one merely about energy makes for a tiresome conversation and largely misses the point. Just because you can make a loose connection with the topic at hand doesn't mean that discussion is relevant.