Actually garbage / messing up ecosystems is a different type of problem than obtaining resources. It is somewhat related to the second law of thermodynamics. Once you introduce so much entropy into a system the genie is out of the bottle.of course this isn't exactly thermodynamics but I can say it this way -- putting humpty dumpty together again is different than figuring out how to make humpty give you more food for decades.
What am I arguing for - that while we do consume more resources, progress is exponential as well. For example if we seriously begin to run out of fossil fuels, amount of effort that is put into other energy sources would increase by order of magnitude and solution will be found. It might not be right away, it might not be silver bullet, but when push comes to shove and there are no alternatives, human ingenuity is frightening.
In the end progress stacks multiplicatively - you add great battery technology to great energy generation technology and you got more than sum of the parts. So more people there are doing research - faster it goes.
This point is only true from certain point of view. Consider genius starting from nill, how far could he take technology within his lifetime? Electricity, probably. Microprocessors and genetics, probably not. Now consider million of people working, each discovery builds on an earlier one, each tool makes other people researching more efficient or enables them to make new discoveries. Now think about multiple generations of people building discoveries on top of each other while sharing information.
