I agree those are factors, but it's not clear they require a new model. From a complexity analysis, the exponential terms will dominate over fixed coefficients

I agree those are factors, but it's not clear they require a new model. From a complexity analysis, the exponential terms will dominate over fixed coefficients, which is what i take your factors to be. In other words, how much livestock, ethanol, etc. do we need? That's mainly dependent on # of people, not living standard. Ofc it's more complex, but again, not clear the usual ecological model won't work and indeed it appears to be.