Interesting computations, Joe F. Kinda hard to visualize, but still makes you think.

The people whom I trust have computed ocean productivity, arable land, accessible fresh water, safe living areas...etc., and estimated that the 'optimum population' is somewhere around 2-2 1/2 billion. We passed that in the 1950s. We who post on this forum are in reasonably good shape....in Somalia, they are not.... and there is little 'reasonable' land left to build on in S. California.

(this page goes into some detail about calculations)