- Ozone
- Efficient Lighting (LEDs now, but others before)
- Santa Claus
There are certainly examples of a large portion of the population of the planet working together towards common goals. A lot of people putting in a little bit of effort _does_ happen, and it _does_ produce results.
I agree with you and that’s why I’m believe soy will conquer the humans nutrition sooner or later. It already is the undisputed king of world-scale animal nutrition because it’s cheap and super nutritious. The drawbacks in Brasil happens because of its success, replace by another crop and the problems will be even worse.
Replace animals proteins for humans by soy for human and you can divide world soy production by ~5.
Improvement of the ozone hole wasn't from millions of consumers making different choices, it was from government regulation and choices of the few leading corporations in particular industries.
Efficient lighting is a mix of regulation against worse lighting and individual consumer economic self-interest, lowering their electrical bill (and sometimes longer-lasting bulbs).
Neither of these are examples of large numbers of people choosing to sacrifice something for a common goal.
There was a profit motive in all of those except Santa. For instance until the main players in CFCs (which were the main cause of ozone depletion) were able to invent, patent, and market an alternative to CFCs they successfully lobbied against any change. Then they got a new patent, turned 180 degrees, claiming CFCs were the worst thing to ever exist - and made a ton of money after they were banned. Same thing with stuff like asthma inhalers.
When people want to do something, we're unstoppable. But unfortunately that means the good and the bad, and right now polluting actions are incredibly beneficial, and the alternatives are mediocre and not only unprofitable, but generally incur a substantial cost. There's a reason places like the US/Canada/Australia talk a mean game about climate change, yet remain some of the biggest polluters per capita, by far.