According to the Talmud, Noah was commanded to desist from procreation on the ark, since it contained only enough provisions for those who entered the ark. There would thus seem to be some rationale for people who take the Bible seriously to practice and advocate zero population growth. But we should look more deeply into the problem. Perhaps what the world needs today is not ZPG, but ZPIG, zero population-impact growth. For it is not just the number of people that is important, but how much they produce, consume, and waste.
Affluent nations have an impact on the environment very disproportionate to their populations.
It has been estimated that an average American has 50 times the environmental impact of an average person in poor countries, in terms of resources used and pollution caused. It should be noted that wastefulness, injustice, heavy military spending, and inequitable distribution of resources are also responsible for current world problems. Most people connect the widespread hunger in the world today to overpopulation. Yet, several studies have indicated that there is currently enough food in the world to feed all the world's people adequately, and the problem lies in waste and inequitable distribution. For example, in the U. S. over 70 percent of the grain produced goes to feed the 9 billion animals destined for slaughter each year, and two-thirds of our exports are used for animal feed, while at least a billion of the world's people lack enough food.