Our contemporary world is host to two coexisting but fundamentally different-and, in at least one crucial respect, contradictory-realities. One of these might be termed Political Reality, though it extends far beyond formal politics and pervades conventional economic thinking. It is the bounded universe of what is acceptable in public economic-social-political discourse. The other is Physical Reality: i.e., what exists in terms of energy and materials, and what is possible given the laws of thermodynamics.
For decades these two realities have developed along separate lines. They overlap from time to time: politicians and economists use data tied to measureable physical parameters, while physical scientists often frame their research and findings in socially meaningful ways. But in intent and effect, they diverge to an ever-greater extent.
The issue at which they differ to the point of outright contradiction is economic growth. And climate change forces the question.