I remember buying a childrens-print magazine, as a kid in the 80s, that had a bit more expensive special issue, but each sold copy was supposedly used to buy a couple of m² of the rainforest.

They marketed it in an "own a piece of the rainforest" way and kid me was super stoked about the idea of owning a piece of rainforest, imagining how I would be living there.

I think it might have been Yps [0], but I'm not 100% certain.

[0] https://en.wikipedia.org/wiki/Yps_(comics)