Objectively if we were to scale back enough, many people currently struggling would die. Excess is the only reason they're still living. Think the rainforest and rain passing the canopy trees enough to still allow life below. Remove the mass amount of rain, that ecosystem suffers.
I'm all for an individual decreasing their own consumption for the environment. I try to do that. But decreasing someone else's quality of life is where it gets dicy. You can very easily get discrimination.
Maybe I'm misunderstanding degrowth. Is it trying to decrease GDP? How does it do that? Or is it moreso increased worker rights and protections with decreased GDP growth as a byproduct? Because I'm all for the second version.
Put a high upper limit only. Don't touch the bottomline.
For example, no more than 4 cars per person: Average Joe won't even know this rule exists but it will still reduce mineral mining due to people who collect cars.
Possible problems with my shitty example: Now a car is a controlled substance. Who decides the limit and how? What if there is a mental disease (with a better example this would make more sense) which requires a person to have 20 cars?
I believe that's called Clarkson's Disease and mostly affects lovable assholes.
I think a better solution is to give everyone less reasons to need and use cars, that a ban becomes unnecessary. But if we're putting limits on things to reduce their consumption, that's what excise taxes are for, most places already do it for fuel.
And of course there could always be taxation relative to a person or company's environmental impact. People get angry at this one.
Decreasing someones consumption will likely decrease their quality of life. Assuming they wanted to maximize their quality of life, they would consume what would do that. Though there are exceptions, like limiting addiction or short range fights.
Lemme give you a very small concrete example where reduced consumption will not alter the quality of life.
Take a small neighbourhood, maybe 10ish families there. Everybody in that neighbourhood has basic tools that they use maybe once a month or less. Hammers, screwdrivers, spanners, etc. Instead of each family having those tools, have a tool library where you have 2-3 of each tool. Anyone in the neighbourhood can borrow the tools they need when they need them and give them back when done. Congratulations, you've reduced tool consumption by 70-80% with no downsides.
This is just one small example, but there are methods for more efficiently allocating resources within communities.
You decrease quality of life by increasing travel time and resistance to getting the tools, plus rarely not being able to use a tool because it's in use. But it is an efficiency improvement. Same idea with gymns, everyone can share one place instead of duplicating resources. But then you need to make sure everything gets put away and you need to keep the lights on, so you need to charge for it. All that works under normal markets. It's just not as good as ideal because people take advantage of each other. We need more oversight to minimize that, but I don't think it means throwing out the system.
I don't think walking 1 minute to a library inside your immediate vicinity qualifies as a reduction in QoL. Fair point on the potential very unlikely case of 5 people all needing a screwdriver at the same time, but that can be solved by buying 1-2 extra screwdrivers.
I went to this example specifically because I thought it was not controversial and low-hanging fruit. Nobody is talking about throwing out the system. Book libraries exist, and they haven't caused the downfall of modern civilization. All I'm trying to say here is that even in the context of our modern capitalist reality, there are ways of reducing consumption without any aggreived parties that we're just not doing.