Every time I think we can somehow “muddle through” climate change and only be arguing about how much a carbon tax should be, I see a study like this one from the National Academy of Sciences that posits a continuation of warming, even an acceleration, that could leave Earth in a “hothouse” condition for millennia.
In other words, we could just “overshoot” the mark and not be able to reduce temperatures again for millennia. This is the stuff of science fiction. But imagine as we get hotter and (on paper) more prosperous over the next few decades that everyone in the Earth’s cities (now over 50% of all people and on its way to 67% by 2050) has air conditioning. For most people that would mean individual “window shakers” that are quite inefficient. It’s easy to see that this is a “runaway” phenomenon, with ever hotter temperatures requiring ever more use of A/C.
The most important thing we can do right now is to work on the built environment with massive trillion-dollar retrofit programs that will reduce the need for A/C in the years ahead. That’s the true infrastructure investment that is currently lacking. Somehow the green building and energy efficiency community needs to figure out how to get building retrofits prioritized.