A median income with a median cost of living and a median lifestyle won’t do it, obviously. Otherwise everybody would be retiring early.

There’s a lot written about finding remote, high-paying jobs and then living like an ultra-frugal bachelor. That’s actually much harder to do than people like to admit and the lifestyle isn’t for everyone.

The more common approach is to get married, keep expenses reasonably low but don’t torture yourself, and one or both spouses should have a moderately high paying professional job. Consistently invest the difference between income and expenses for a few decades and you’ll get there.

Nobody is retiring at 30 and living like a king unless they’re extraordinarily lucky with a startup or some other gamble. However, it’s very reasonable to retire before the age of 50 or even 40 if you’re smart about it and willing to live a moderately priced lifestyle.

Also I'm really curious what people consider valuable environmental work - like, if you didn't have to work for money tomorrow, what kind of environmental work exactly would you take on?

For example, in my area I would probably push for the local mangrove coast line to be protected from development. Or perhaps for my county to ban or somehow restrict two-stroke engine use.

The same as retiring in any other field.

make half a million dollars per year total comp, duh.

It's more complicated than I make it sound there but ultimately it's a matter of deciding it's important to you to do this and making it happen.