Earlier quoted context omitted.
Well, I think this would be the simplest: the temperature at any given latitude will be the average of the last n years. Period. But maybe I'm too naive.
Simplest, but not optimal. Ideally you'd want to settle on a mean that: a) Maximizes arable land, b) Minimizes climate-based natural disasters such as hurricanes, and c) Is as near to self-sustaining as possible. That is, the global mean should not lead to significant growing or shrinking of ice caps and glaciers, nor significantly alter carbon uptake by the oceans. While some degree of human control could make up fo…
there are some lands on the periphery of existing arable zones that might become desirable in the short term, but certainly there will be a net loss worldwide...local economies have grown around existing arable zones, you have to transplant all that too