What controls the growth of human population?
Famine was what kept human populations low in the past. Then there are a long list of diseases that decreases the survival rate (cholera, malaria, yellow fever, polio, tuberculosis, small pox, etc), not to mention epidemics like the plague (black death), warfare, etc. Periodic droughts and floods also take their toll. Then there are major volcanic eruptions that may cause world wide crop failures for years, even decades. Human populations are growing rapidly because there is an abundance of food supply, and we have not had a war like the first or second world war for over half a century, and we have managed to keep many diseases in check. Advanced communication, shipping and food distribution have allowed developed countries to help out developing countries experiencing famine. If the human population keeps increasing, and we have a disaster such as a gigantic volcanic eruption that blocks the sun and causes major crop failures, then we may find a shortage of food that could in turn le
