Bill Rankin, 2015
Just under 88 percent of humanity lives in the Northern Hemisphere; 82 percent lives in the Eastern Hemisphere. (And I have the graphs to prove it.) But of all of the infinitely many hemispheres that could divide the earth into two halves, which has the most people of all?
The hemisphere shown here — the Human Hemisphere — contained 92.9% of all humans in the year 2000, the most recent year with global data available. Its center is in western Switzerland, at roughly 42.5°N, 7°E. (A more exact value isn't possible, given the imprecision of population data from around the world.) Not surprisingly, the Human Hemisphere is not so different from the Land Hemisphere (the hemisphere with the most land); the main difference is that the Human Hemisphere contains more of Southeast Asia and less of South America. This is not the same as the so-called center of population, but it could still give some insight into things like airline hub-and-spoke patterns, satellite broadcasting, or the location of global financial centers.
So it looks like there might be some justification for Eurocentrism after all, at least geographically. Ah well.