Good story, you've said a few things many of us might have asked, and it's good you put your conclusions on some good research. It's important to know our real impact, it definitely helps my own efforts, which have been to show why and how we need to move completely to solar, from extracted energy dependence.
Most folk separate out our metabolistic energy requirements from our utilities energy requirements, but you've noticed wood is still used for a lot of cooking, to me we have to put all energy requirements in one pot, but not all sources of energy.
There is only one actual source of energy, and we only just recently got the technology to start using it on a widespread universal domestic and community basis, it's the sun of course, but the way we have used it so far has not done as much as it could to change our rate of consumption of energy resources.
The other really important thing that needs to be considered is the effect of consuming energy resources directly on temperature. This is neglected in favor of seeing CO2 as the root source of temperature rise, when it isn't, CO2 production is a symptom, a result of consumption of energy resources.
The reason we prefer to spend time working on CO2 rather than on consumption of energy resources is that it makes profit to manage symptoms. Whereas fixing problems removes the possibility of making profit. And profit itself requires consumption of energy resources. See how it works? Profit locks us into consumption of energy resources.
We've done this so long we've almost lost the ability to questiion it.
But it seems indigenous people did know this, their religions and spiritual beliefs generally warned them profit was wrong, so maybe they weren't locked into extraction of energy resources economically like we are, but they obviously still had the inevitable harmful effect of consuming many species of life, and clearing forests, just slower. Profit just made us much better at consuming, it supercharges our rate of consumption.
You mentioned that 30 percent of carcasses didn't get eaten by humans, an interesting question to me is how would we know? Were the partly eaten carcasses physically preserved to show them only partly eaten, and wouldn't the process of preserving them stop them from being eaten by other things, like vultures, worms etc, if humans never ate them?
Anyhow, interesting distractions aside, the main point is; modern humanity has an energy requirement to metabolise, and an energy requirement for creature comforts. Those two alone (M and C) we can easily supply from domestic and community solar.
By creature comforts I include even aerospace, trips to the moon etc, it cam all be done on domestic and community solar, we just need to back it all up with hydrogen, and stop expecting to make profit with it.
Associated with profit are all the financial industries. Those have to go, surprise surorise.
We just can't afford them any longer, and they don't actually add value, they just heat the planet for the hell of it, litrrally. They actually can't exist in a fully solar powered scenario because the energy from the sun has no component in it for profit. The Joules / kWhrs received from the sun come for free, nothing asked in return. The sun is not interested in profit, it donates everything. This might be the part we need some indegenous spirituality to get our heads around, "nothing comes for free", is a fallacy, the truth is everything comes for free, it all came from the energy of the sun for free, and we have to include and treat the sun as a valid stakeholder in all our considerations, we have to treat it as a live thing with real consequences if it is ignored. Its only requirement of us is that we actually do put it to use. If neither we nor nature uses it, it heats the planet, and like you said, we already removed a large part of nature that used it.
BTW, check out "Solein", and notice the input energy component of it is hydrogen. Notice also widespread production and use of hydrogen by transportation would result in widespread filtration and circulation of water. Then we should conclude with these we can reduce our burden on nature, allowing it to recover at least a little.