How does productivity translate to sustainability? Historically, as countries became more developed and increased productivity, they also increased resource consumption.

Growth has its limits. It is generally sigmoidal (S curve), not exponential. It’s reasonable to assume we’ll hit the inflection point long before the sun becomes a problem.

My point is that we’ll need to find an equilibrium that doesn’t rely on continual growth, because that won’t be sustainable. After we manage that, there’ll be still enough time to worry about the sun. And if we don’t manage that, human life on Earth will be doomed regardless of the sun.