Not sure if anyone is or cares to follow the counter argument I'm making about possible limitations with the consensus view... So I'll probably just end up arguing with myself.
Let's say that we live in a city of pigs where excessive indulgence is the norm. What would moderation look like then?
If it was common for people to go out on drinking bouts and have orgies every evening, then would moderation be every other evening? Would it be alright to feel good about oneself relative to the cultural norm?
What about the degree of pollution? If we only throw away one plastic bottle for every common person's three, then should we pat ourselves on the back?
Comparing oneself to others and cultural standards in determining moderation seems to be a flaw, even if it makes people feel good about themselves. Is this making sense to anybody?
I generally think it's better to compare activities to long-term sustainable species norms than current cultural fads, when it comes to determining what moderation is. Using a "city of pigs" as a basis would be a bad sample because it would be such a small sample of humans in time and space.
Two animals, for example, may use sex with different frequencies and for different purposes. Bonobos get it on more often than tigers, for example. What would be considered "moderation" is based on species norms.
Humans also use sex for both pleasuring and bonding and to a lesser extent, reproduction. Humans naturally desire tasty good food because that's the drive that has kept people alive. Humans generally don't naturally think in terms of sustainability because for most of human history with reasonable population levels, it hasn't been an issue other than conserving resources for winter.
Some things become excessive when used in ways that sort of "trick" the natural biology and cause harm. For example, people desire fats because in nature, fats are healthy energy and relatively hard to come by. But when processed fats and carbs are cheaply available in limitless quantities, this healthy and natural desire can be tricked into excess. It becomes a case where desire and health are at a mismatch for a lot of people, so it requires control. I think moderation means eating what is biologically and psychologically healthy for a human to eat, which has a range of correct answers but is not entirely subjective.
Sex has kind of moved in the opposite direction. With reliable methods to substantially reduce the risk of diseases and pregnancy, the dynamics of reward and risk have shifted. On the other side of the coin, just about every species starts having sex when they reach the age of reproduction, and humans reach the age of reproduction in their early teens. But with social views about not having sex until marriage and then having the average age of marriage in the mid or late 20's (plus crap ideas like trying not to teach kids anything about how sex works), the culture just doesn't work with the biology and so people of basically every culture find ways to ignore that idea. I think moderation means having sex at a frequency that meets the emotional and physical desires of the individual and her or his partner(s), and that is safe and consensual.
Basically by definition, everything that is environmentally unsustainable is excessive, even if it is less than that of peers. I can't see how it could be argued otherwise. Species must develop equilibrium with their environment. The problem people face is that so much of their environmental infastructure is unsustainable that even if they try really hard to be sustainable, they're most likely still being just "less unsustainable". For someone to try to have no negative environmental footprint in this culture is quite difficult- it can mean not having most forms of jobs and commutes, giving up travel to see family, avoiding all major places of purchasing things to find niche sources of sustainable goods and food, avoiding most electronics, etc. Basically, unlike things like sex and healthy eating where moderation is fairly easy to obtain, to be environmentally reasonable today requires being radical. Some people may pursue being radical but I think other people just have to work to change the culture by reducing things in their lives where they can, being mindful of population growth from themselves (since prior population growth was not their fault), and by bringing more awareness for the need to really reign things in environmentally. For most of human history being sustainable and moderate wasn't too hard but now with transportation and plastic and corporations, and especially overpopulation, one has to swim against rapids to make it work if they want to literally be sustainable.
