Gloom and doom predictions

John Tierney, arguing for the need to balance uncertain future events against certain costs today, examines past prophecies of over-population;

* Four decades ago, scientists were so determined to prevent famines that they analyzed the feasibility of putting "fertility control agents" in public drinking water; the physicist William Shockley suggested using sterilization to impose a national limit on the number of births.

* Planned Parenthood's policy of relying on voluntary birth control was called a "tragic ideal" by the ecologist Garrett Hardin, arguing that "freedom to breed will bring ruin to all."

* China's one-child-per-family rule, which, ostensibly was voluntary, but the penalties were so severe that there were reported cases of forced abortions and infanticide.