To make half the Earth's surface wild, ecoregion by ecoregion, would require moving a billion humans out of those wild areas.

This will be much easier if we work hard to reduce the human birth rate. The human population is predicted to peak 9 or 10 billion, but I expect a big increase in deaths to set in during this century as we rush towards ecocide. The human population will decrease — sooner than predicted — in a gruesomely painful way. We can avoid those deaths with a strong effort to reduce births first. This would also make space (physical and economic) for those billion people to move to.