Given the intrinsic momentum of population growth, the range of plausible trajectories for the size of global population is quite narrow over the next few decades. For this reason, increased action by Governments to limit the growth of populations can do little to mitigate the forces of climate change between now and 2050. A lower birth rate over the next few decades could begin to have a significant impact on global trends only in the latter half of the century, after the current momentum dissipates. At the same time, in many low-income and lower-middle-income countries, rapid population growth remains a matter of concern.

The following key findings are based on the report Global Population Growth and Sustainable Development, prepared by the Population Division of the United Nations Department of Economic and Social Affairs (UN DESA).