> Is there an example of any we have already passed? Reading about nature before humans or where humans settle shows that what passes as nature today is nothin

> Is there an example of any we have already passed? Reading about nature before humans or where humans settle shows that what passes as nature today is nothing like it used to be. That we are mostly ignorant of it doesn't change that we've passed many tipping points. Each extinction, for example, is irreversible and everyone here knows we're causing more than ever. I recommend The World Without Us by Alan Weisman (audiobook free on youtube: https://www.youtube.com/watch?v=W8z6vsg1OH8 https://www.youtube.com/watch?v=W8z6vsg1OH8) and The Once and Future World by J. B. MacKinnon http://www.jbmackinnon.com/index.html http://www.jbmackinnon.com/index.html. I recorded a video essay on Once and Future World: http://joshuaspodek.com/your-daily-environment-009-the-once-and-future-world-8-9-19 http://joshuaspodek.com/your-daily-environment-009-the-once-.... We've crossed tipping point after tipping point. We just don't know what we've lost.