[IamIan]

Originally Posted by jamesqf

But those calories are, in most cases, being gathered from sources that humans can't utilize directly. For one simple example, humans can eat only a small part of grain plants such as wheat or corn. Grazing animals can eat the whole plant, and turn any excess into fertilizer to boot, as well as providing numerous other ecosystem services.

We intentionally plant things to feeds the cows and such to get our meat .. it is no accident that those plants are not indented for human consumption ... we can (for fun) look at how meat eaters actually get the meat produced in the real world .. and the massive environmental damage their meat eating is actually doing compared to if they didn't eat meat.

Also ... any part of the plant that a human doesn't eat ... will decompose into soil and fertilizer without the need to be eaten by some other animal like a cow... Thus that ecosystem does not ultimately suffer from the loss of the giant herds cows to produce our 66+ Million Tons of Beef per year... there are more herd cows in the US than humans.

It's like if someone advocated for being able to net better overall MPG by adding a horrible 5% efficient (20:1) energy converting step between the ICE and the Wheels that all energy has to flow through to get to the wheels... it makes things worse .. not better.

Originally Posted by jamesqf

For a different argument, we might step back a bit and ask why, if meat-eating (or carnivory/predation in general) is so inefficient, it persists despite several hundred million years of evolutionary pressure to eliminate inefficiency?

Evolution does not pressure to eliminate inefficiency ... Evolution does one and only one thing ... reward that which breads the most , who live long enough to themselves bread ... that's it.

Even if you want to try and draw a indirect correlation ... Meat eaters still loose and loose horribly ... there always in all stable / sustainable ecosystems far far fewer meat eaters than plant eaters ... meat eaters are in the evolutionary minority, by a large margin.

Originally Posted by jamesqf

But that's my argument: unless & until ecology becomes an exact engineering discipline, a sustainable population has to be low or zero impact, otherwise the impacts eventually cause the system to collapse.

Or ... it doesn't collapse... maybe it thrives.

Not knowing all details ... does not guarantee being wrong about every decision one makes ... nor does it guarantee collapse or 100% complete failure.

Also just because we don't know 100% everything ... doesn't mean we know nothing (0%).

Edison knew next to nothing about what electricity even was .. or what was going on ... etc ... and none of that prevented his light bulb from working.

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Originally Posted by P-hack

Ian seems in diversion mode.

Well I'm not.

Originally Posted by P-hack

But since there is no data to suggest unrestrained population growth is a good idea

AFAIK there is also no one claiming it is a good idea.

Originally Posted by P-hack

You can't look at the huge numbers of farmland, then take more fore renewable energy, and the vast number of people, and believe for a second that we aren't extinguishing other species pell-mell.

Well we , don't have to take farmland for more renewables ... so that's mute.

We could reduce (nearly all) the farmland damage being done in order to grow the grain and such , in order to produce the 320 Million tons per year of horribly low (5% or less) efficient , high polluting , unnecessary , luxury , meat eating... that's a lot.

At roughly ~2.9cal/g (Beef).. and the low 20:1 input to output ratio.
That's (roughly)
~843,636,363,636,363 meat output Calories
Inputing ~16,872,727,272,727,272 input feed Calories to get that output.
Or if you like that in energy terms closer comparable to RE.
~1.162 Wh per Food Calorie

~19,606,109,090,909,090 feed input Wh of energy per year
~19,606,109,090,909 kwh
~19,606,109,090 Mwh
~19,606,109 Gwh
~19,606 Twh
~19 Pwh

That's a big number of energy (and all the land and other resources that were used to produce it)... just for the luxury item of meat.