How would IH solve this "unsolvable" problem?

I think you are fighting a losing battle trying to change individual behavior, generally people follow the path of least resistance until sufficiently motivated to do something different.

For power, what needs to happen at a larger scale is power needs to be generated from renewable energy sources (or fusion somewhere in the future, but that's decades away at best ). That takes away a lot of issues with people using power. Though for lightbulbs, using LED bulbs is probablly a good idea.

For water, taps, dishwashers, and washing machines all need to change to be more efficient. Regulation could be a tool here. I work doing monitoring systems for residential / agricultural water usage / irrigation and a lot of efficiences / lekage can be solved simply by knowning what's happening with water.

For waste, probablly the hardest thing, we need regulation to stop the massive amount of waste generated from single high use products. Not sure exactly how you'd craft regulation like that, but I'd imagine some kind of tax on packaging based on its enviromental impact. Hopefully that will be motivation for products to evolve.

Hmm,

I grew up in Atlanta with Immigrant parents.

We were banned from using the washer unless there was a full load.

Lights on during the day? You must be joking. If it’s night and you’re leaving a room, turn everything off - or else.

The dish washer? What’s wrong with your hands?

I don’t get the cotton earbud thing.

Turn off that tap - water isn’t free.

For me, being conscious of how I use things has been ingrained in me since a young age. It’s now part of the way I live.

My living expenses are less than $1,000 a month and I have plenty surplus but those habits have stuck with me.

I think it’s something we need to tackle from a young age because it’s notoriously difficult to change the ways of adults.

Then, the adults are the ones who will change the children so what do we do?

But, I don’t think this is an indie hacker type of problem though. It also won’t be solved until it has to be.

It’s a massive societal change and the pain of not being environmentally conscious hasn’t outweighed the pain of being environmentally conscious.

I don't see this as a problem suitable for an Indie Hacker approach, you are talking about population level changes in conscientiousness.

In your household case it's about persuading people to your view - it's quite a skill to do this without coming across annoying or holier than thou.

I have a friend very similar to you who did her best to solve this by sticking friendly post-it notes everywhere, most people didn't pay attention. She did get through to me eventually, someone who did care about the environment but at the time wasn't highly motivated to be careful of my personal effect. I think those kinds of people should be the target, rather than the many people who simply aren't interested. I'm not sure how you would leverage technology to persuade people though, she only got through to me because I cared about her and so was content to listen to her lectures.

Don't let too much of your energy get sucked into this, a lot of socially conscious people just get jaded and frustrated because others don't care as much as they do.

Do you have any ideas for what a solution might look like?

I wonder if maybe an app where each roommate is presented with a scorecard, where they can score:

1. self contributions to the household
2. peer-contributions to the household
3. a special section for critical contributions like "pays rent on time, or late"

Scores could be presented as averages, so that there can be some level of anonymity. Each roommate then gets a list of suggested actions/improvements for themselves, and hope they score better the next time everyone convenes.

Would you be able to measure and calculate how much money are they spending per year? Sometimes a different approach could work.

Do you pay for water and electricity by usage or is it included in your rent? If you're paying for it, that's the easiest way to get to them. If it's included, then you could try other approaches, such as putting the lights on timers so they just turn themselves off, and putting putting a sensor in the shower that sounds a siren when it's on but no one's in. It depends on how much you want to keep your flatmates.

I'm environmentally conscious, they are far from it.
They use cotton earbuds (those little ones on a plastic stick)

You must be fun to live with 🤣😂😅

Well in 100 years when there isn't an environment left the problem will have taken care of itself.