Around the world, rainforests are becoming savanna or farmland, savanna is drying out and turning into desert, and icy tundra is thawing. Indeed, scientific studies have now recorded "regime shifts" like these in more than 20 different types of ecosystem where tipping points have been passed. Around the world, more than 20% of ecosystems are in danger of shifting or collapsing into something different.
It’s so much easier for common folks to read this articles (written by the actual researchers of course) than the actual papers.
When I learned about tipping points and collapse of ecosystems I instantly thought about the time when I was into fish tanks and helped other people on the hobby. If you let that thing go sideways in any way for too long, you were facing catastrophic consequences, be it plagues of snails, algae, etc. At some point it just goes downhill, and most of the time the buildup is unnoticeable and when you do notice that something is off, it’s already almost impossible to save the ecosystem.