Ronsterm I am of the opinion that the Earth is either at or close to maximum human population if we want everyone to enjoy a good quality of life without destroying what is left of the natural environment.
Right now over half of the world's people live in poverty just managing to survive from day to day. There is still some land that has not been exploited for agriculture (especially in Australia) but do we really want to farm all the arable land on the planet and lose almost all of our natural environment and certainly all of our wilderness excepting Antarctica of course?
The stocks of wild food, mainly in the seas, are rapidly declining through over exploitation. Do you really want to worsen this by trying to feed more people.
Do you really want to spend money that you say is currently wasted on wars etc on trying to meet the food, shelter and health needs of even more people ? I think that money would be better spent on trying to improve the situation of the billions now living in poverty.