An informative, well-researched thought experiment. I’ve often wondered if the world would be better off without humanity. I strongly felt that the answer would be yes, and that is now backed up with substantial evidence. A depressing conclusion. I’m glad that I read this book, but I can’t say that it produced any feelings of optimism. The bottom line: humans are reeking havoc on the planet and the effects are past reversing unless huge global changes are made, especially in population growth rates. The earth will recover from our presence after a significant amount of time goes by after we are gone. I guess that’s a kind of optimism in itself.