Enacting laws which limit people's freedom to reproduce.
India implemented the world’s first national family planning program in 1952. The birthrate began to drop, but only gradually, and family sizes remained stubbornly high. The government then implemented widespread forced sterilisation particularly of Muslims and the urban poor, especially during “The Emergency” years of 1975-77.
After the founding of the People’s Republic of China in 1949, infant mortality dropped significantly. Between 1950 and 1980, China’s population almost doubled. The “one-child policy” – limiting births per couple through coercive measures – was implemented in the early 1980s, and fertility dropped dramatically.
In an over-populated world only government intervention in family planning will stem the tide.
It is not widely agreed that any government may intrude upon the individual's choice to reproduce as they wish. Consequently, such legislation is very difficult to enforce.
The conference document of the United Nations' World Food Summit (Rome 1996) praises China's population control policies, which include abortion, infanticide, and forced sterilization. It encourages all nations to follow a China-like program of "family planning" to control population levels so that there are fewer mouths to feed. It endorses every country to monitor and control population growth to make sure there is enough agricultural land to sustain the population.