The idea is right there in the name: leave about half the Earth’s surface mostly free of humans, so wild plants and animals can live there unimpeded as they did for so It wouldn’t have to be imposed it’s happening anyway. Same with the oceans, by the way; about a third of our food comes from the sea, so the seas have to be healthy too.
At a time when there are far more people alive than ever before, this plan might sound strange, even impossible. But it isn’t.

https://www.theguardian.com/cities/2018/mar/20/save-the-planet-half-earth-kim-stanley-robinson

Empty half the Earth of its humans. It’s the only way to save the planet _ Cities _ The Guardian

This is from 2018 but became popular on this day