If you were a programmer adding an extra feature to an existing system, and after a few days work you realize that 90% of the system has been modified by you in some way or another, won't you be alarmed?
In 200 years, many species have been driven to extinction by our activities, entire forests were chopped away, and countries are now sinking due to rising ocean levels "http://en.wikipedia.org/wiki/Maldives, and you're still not worried?
It's fine to be "disconnected from nature", as long as everything can keep going the same way, but I don't think they can. Our own artificial infrastructure is like a ponzi scheme, requiring ever increasing amounts of resources to support it. Until you can find a way that it'll support itself without killing everything around it (I'm not exaggerating, your roof is a desert.), it is not sustainable.