Short answers, pulled from the story.
Family planning, as defined by the United Nations and the World Health Organization, encompasses services leading up to conception. It includes contraception, sex education, management of sexually transmitted infections, pre-conception counseling, infertility treatment, and abortion, though abortion is not considered a primary method.
Family planning is among the most cost-effective of all health interventions. The UNFPA states that for every dollar invested in contraception, the cost of pregnancy-related care is reduced by $1.47. The Copenhagen Consensus ranks universal access to contraception third among all policy initiatives for social, economic, and environmental benefits per dollar spent.
According to the United Nations Department of Economic and Social Affairs, 12% of the world population's need for contraceptives is unmet. The UNFPA estimates that some 225 million women who want to avoid pregnancy are not using safe and effective family planning methods. Most women with unmet need live in 69 of the poorest countries on earth.
China's one-child policy, beginning in 1979, forced couples to have no more than one child in order to curb rapid population growth. It reduced the fertility rate from about 2.75 children born per woman to about 1.8 by 1979 and reduced the population by about 300 million people in its first 20 years. The policy was officially phased out in 2015 and replaced with a two-child policy; in 2021 China announced couples could have three children.
The research project Drawdown estimates that family planning is the seventh most efficient action against climate change, ranked ahead of solar farms, nuclear power, and afforestation. A 2021 paper by William J. Ripple, Christopher Wolf, and Eileen Crist notes that the richer half of the world's population is responsible for 90% of emissions, and argues population policies can advance both social justice and climate mitigation.
Global consensus that family planning is a human right was secured at the 1994 International Conference on Population and Development in Principle 8 of the Programme of Action, which affirms that all couples and individuals have the basic right to decide freely the number and spacing of their children. The 2012 London Summit on Family Planning produced the Family Planning 2020 movement, in which more than 20 governments committed to removing policy, financing, and cultural barriers to contraception access.