World Population Growth and Distribution

World population passed 8 billion around November 2022, according to United Nations estimates, capping a trajectory of unprecedented growth: from roughly 1 billion in 1800, to 2 billion by 1927, to 5 billion by 1987, in barely two centuries. Growth accelerated sharply after 1950, once mortality began falling faster than fertility across most of the developing world, adding billions of people in a few decades. The UN Department of Economic and Social Affairs (UN DESA), in its World Population Prospects, projects that growth will keep slowing rather than reversing abruptly: global population is expected to peak at a little above 10 billion sometime around the mid-2080s, before entering a slow decline through the end of the century. Nearly all of the remaining growth is expected to occur in a handful of countries, with India, Nigeria, Pakistan, the Democratic Republic of the Congo, and Ethiopia together accounting for over half of the increase projected between now and 2050. The pace of this transition has surprised demographers more than once: fertility has fallen faster than earlier UN rounds assumed in many regions, which is why each new revision of the Prospects has tended to lower its long-range projections compared with the one before it.