Re: a fragile "Mother Nature" is harmed by anything humans do
"Animal populations naturally level out at the resource levels the environment can sustain"
Yes, and humans are no exception to that rule. Luckily so far, technology has sustained our ability to support growing populations by increasing the resources available to us. Of course this could continue in the future (for example we better harness the available uranium / thorium resources via more nuclear technology, or further down the line utilise deuterium etc resources for fusion, and so on).
The thing to keep in mind, though, is, there is never any guarantee that our technology advances will keep pace with the advances in resource requirements, and resource requirements are rising remarkably fast now because not only are populations rising but also resource use per capita is rising even more steeply.
One side of this argument should realise that future resource availability (eg oil) is not guaranteed, and they'd better have some sort of plan to keep future resource availability in mind, not just take what they can now and screw the future. The other side should realise that simply obstructing any and every measure for new development will eventually block the development of new resources.
The trick, as always, is in the balance