Yesterday I ran out of peanut butter. The jar had a bunch of little bits of peanut butter left in it so I needed to wash them out before dropping it in the recycling bin. Problem is that peanut butter is really greasy, sticky and annoying which necessitates using a ton of water and soap to actually get the thing clean. I got to thinking about how saving water and soap is a good idea and recycling is a good idea... so how much water and soap would I have to use before recycling a peanut butter contained is not worth it? Answer: I have absolutely no idea. Moreover I don't think anybody has a decent sort of answer for these types of questions.
Clearly when we have a choice of a long shower or a short shower the green choice is easy but how do we go about making these decisions where we have to trade off one problem for another? In much of life we can reduce choices to simple cost evaluations where everything is expressed in terms of dollars and cents but that doesn't work well when things don't have a value that works. Water is cheap as hell of course but it makes sense to treat it as more expensive than it is because in many cases we are borrowing against future yields. Recycling is a foolish thing to do from a strictly personal perspective because it benefits me zero and the labour involved in doing it is something. I can't value these things on any shared scale.
This is all made much worse by articles that talk about how "The wars of the 21st century will be over water!" and environmental propaganda that talks as if every tree, molecule of oxygen and drop of fresh water simply has infinite value. When people talk about these things they present their case without any sort of dollars and cents argument most of the time because the dollars and cents argument would be completely unconvincing. That does leave me up the creek though in trying to make these small choices. Air conditioning vs. sprinker? Paper vs. Plastic? If I can spend 10,000 gallons of water and $5,000 to get 500 tonnes of CO2 out of the air is that a good idea? The calculations are simply impossible even from a macro level and there is no way the average person looking at them can make good choices.
Generally of course we can make significant progress just be getting people to make the obviously good choices and letting them do whatever they please when the choices get jumbled. That doesn't stop me from desperately wanting weights and functions for various resources and tasks though. I want to know *exactly* what to do!