Seeing as how "natural economic growth" is not infinitely sustainable (I'm operating under the assumptions that there are finite quantities of natural resources and human ingenuity is not infinite and infallible). It's probabilistically inevitable.
Natural resources are finite, but so long as we can improve our efficiency faster than some rate N, we will never run out of a given resource. Thank you Zeno's Paradox.
(Recycling also plays a part, though I don't know if it should be considered increasing the supply, or increasing our efficiency)
The only one that is a real problem is energy. Thanks to the laws of physics, we may not be able to forever increase our energy efficiency, and energy cannot be recycled.
It seems unlikely to me that we're anywhere close to diminishing returns from technology. More likely we're seeing what happens when a system is full of perverse incentives that reward unproductive / destructive behavior.
