Population & Environment
Human population is projected to reach nearly 9.2 billion under the UN “medium scenario” by the year 2050—up from nearly 6.7 billion today. This projection however, is based on assumptions of continued fertility declines that may or may not happen. Should fertility remain constant at today’s rates, world population could reach 11.9 billion by 2050. Even if global fertility were to decline to a two-child average, so many young people are entering their reproductive years that momentum alone will cause population to continue to grow for at least a few decades.
However, possibilities for influencing population growth exist. By increasing access to voluntary family planning and improving sexual and reproductive health, women and their families can have the freedom to choose the size of their families. Among many other benefits—including better overall health—helping women and couples achieve their desired fertility can ease the effects of rapid population growth on the environment. Population is hardly the only force applying pressure to the environment and natural resources. But the environmental challenges humanity faces in this century and beyond will become harder to address as the number of people continues to increase.
Today more than a billion people live in the areas richest in species diversity and the most threatened by human activities. While these areas comprise about 12 percent of the planet's land surface, they hold nearly 20 percent of its human population. The population in these so-called biodiversity hotspots is growing at a collective rate of 1.8 percent annually, compared to the world's population's average annual growth rate of nearly 1.2 percent. The planet's major renewable natural resources—its fresh water, fisheries and forests—are already strained, and our atmosphere has been dramatically altered. Based on these trends, it is clear that the 21st century will witness even greater pressures on natural resources—with the poorest among us often paying the greatest price.
There are positive signs, and there is hope. Over the past 40 years the average number of children born to each woman has fallen from 4.47 for the period 1970-1975 to 2.55 for the period 2005-2010, and infant and maternal mortality have fallen in most places around the world. Young people increasingly want to wait to have children and to have smaller families. Policymakers have a choice. They can do nothing, or they can commit the financial resources to meet the needs of people who want to have smaller families and delay childbearing—benefiting individuals and the welfare of the planet. Combined with developing new energy- and material-efficient technologies and altering consumption patterns, these strategies can bring humanity into enduring balance with the environment and the natural resources that people will always need.
