[connortomas]

I can see your point, but, taking a longer-term view, what happens when we hit hard limits to global growth?

In a world in which every country is developed and wealthy... where in the world does that material wealth come from? I can't conceive of how such a world could exist without some kind of significant technological breakthrough or massive social change.

[InclinedPlane]

Are there hard limits to global growth? What are they exactly? What's the evidence that the Earth cannot support a population of 10 billion with wealth equivalent to, say, the current US?

Today there are potential long-term problems in the way we use fresh water and hydrocarbons, but those are not fundamentally insoluble, far from it they are immanently tractable engineering problems. Consider that by the year 2100 the global economy will likely be over a quadrillion dollars in size (in 2012 dollars). And it will be filled with millions upon millions more engineers, entrepreneurs, technicians, and so forth than the world of today. I find it hard to believe that such a world will have trouble growing food or operating desalinization plants or adapting to using nuclear fission power, etc.

None of this requires massive social change or technological breakthroughs, it merely requires that people invest money and effort into engineering solutions to problems as those problems develop, which is something mankind has excelled at for millenia and will be extremely well prepared for in the 21st century.