World Population (Paperback)

World population can refer to the population of any organism living on Earth at a given time. This article refers to world human population. As of 1 March 2010, the Earth's human population is estimated by the United States Census Bureau to be 6,805,700,000. The United Nations estimated the world's population to be 6,800,000,000 in 2009. The world population has been growing continuously since the end of the Black Death around 1400. The fastest rates of world population growth (above 1.8%) were seen briefly during the 1950s then for a longer period during the 1960s and 1970s (see graph). The 2008 rate of growth has almost halved since its peak of 2.2% per year, which was reached in 1963. World births have levelled off at about 134 million per year, since their peak at 163 million in the late 1990s, and are expected to remain constant. However, deaths are only around fifty-seven million per year, and are expected to increase to ninety million by the year 2050. Because births outnumber deaths, the world's population is expected to reach nine billion in 2040 or by 2050.