At no time in history were we ever actually in "balance" with the environment. Sure, we weren't as destructive at times in history, but we were always modifying the environment in ways that could negatively alter it.
Technology will help out, but it's going to be a long process, and we aren't going to end up living just like we do right now. Cultural and technological changes will end up being necessary. We have to learn about how to live in balance with our planet, and we have to learn about how to correct the imbalances we've introduced. We can't do this by meditating in a forest--it's going to require research and technological adaptations.