HISTORY- WORLD POPULATION

Ancient & Middle Ages

A dramatic population bottleneck is theorized for the period around 70,000 BCE. After this time and until the development of agriculture, it is estimated that the world population stabilized at about one million people whose subsistence entailed hunting and foraging, a lifestyle that by its nature ensured a low population density. It is estimated that more than 55 million people lived in the combined eastern and western Roman Empire (CE 300–400).

The Plague of Justinian caused Europe's population to drop by around 50% between 541 and the 700s. The population of Europe was more than 70 million in 1340. The Black Death pandemic in the 14th century may have reduced the world's population from an estimated 450 million to between 350 and 375 million in 1400. It took roughly 200 years for Europe's population to regain its 1340 level.

At the founding of the Ming dynasty in 1368, China's population was reported to be close to 60 million, and toward the end of the dynasty in 1644 it might have approached 150 million. England's population reached an estimated 5.6 million in 1650, up from an estimated 2.6 million in 1500. New crops that had come to Asia and Europe from the Americas via the Spanish colonizers in the 16th century contributed to the population growth. Since being introduced by Portuguese traders in the 16th century, maize and manioc have replaced traditional African crops as the continent’s most important staple food crops. Alfred W. Crosby speculated that increased production of maize, manioc, and other American crops "...enabled the slave traders [who] drew many, perhaps most, of their cargoes from the rain forest areas, precisely those areas where American crops enabled heavier settlement than before."

The population of the Americas in 1500 may have been between 50 and 100 million. Encounters between European explorers and populations in the rest of the world often introduced local epidemics of extraordinary virulence. Archaeological evidence indicates that the death of around 90% of the Native American population of the New World was caused by Old World diseases such as smallpox, measles, and influenza. Over the centuries, the Europeans had developed high degrees of immunity to these diseases, while the indigenous peoples had no such immunity.

Modern era

Urban areas with at least one million inhabitants in 2006. 3% of the world's population lived in cities in 1800, rising to 47% at the end of the twentieth century.

During the Agricultural and Industrial Revolutions, the life expectancy of children increased dramatically. The percentage of the children born in London who died before the age of five decreased from 74.5% in 1730-1749 to 31.8% in 1810-1829. Europe’s population doubled during the 18th century, from roughly one hundred million to almost two hundred million, and doubled again during the 19th century.

       The population growth became more rapid after the introduction of compulsory vaccination and improvements in medicine and sanitation. As living conditions and health care improved during the 19th century, the United Kingdom's population doubled every fifty years. By 1801 the population of England had grown to 8.3 million, and by 1901 had grown to 30.5 million.

      The population of the Indian subcontinent, which stood at about 125 million in 1750, had reached 389 million by 1941. Today, the region is home to 1.5 billion people. The total number of inhabitants of Java increased from about five million in 1815 to more than 130 million in the early 21st century. Mexico's population has grown from 13.6 million in 1900 to about 112 million in 2009. In eighty years, Kenya's population has grown from 2.9 million to thirty-seven million.