Over the past few centuries, the world's population has grown dramatically. In fact, some historians believe that the huge population growth is one of the most significant developments in world history.
Anthropologists have traced human existence to approximately 3 million years ago. The earliest humans lived by hunting and gathering. The population was small and nomadic.
By 8,000 BC, some hunters and gatherers started to settle down. They began growing crops and domesticating animals. As people became more sedentary, communities evolved. By the beginning of the agricultural revolution around 8,000 BC, the world population was estimated at 5 million.
By AD 1, the population had grown to anywhere from 200 to 600 million. Diseases, epidemics, and climate fluctuations kept life expectancy short. Although the population continued to grow, it was at a moderate rate of approximately 0.05 percent per year.
A dramatic change occurred with the European Industrial Revolution, which began in the late eighteenth century. Before this time, most people lived in rural areas.
Once industries such as textile and iron production were established, people moved from rural areas to cities and industrial townships. Industrial jobs helped families improve their living standards. New agricultural techniques increased the food supply. New medicines and medical techniques increased life expectancy. Epidemic diseases decreased. These factors all caused the population to grow rapidly.
In 1685, England's population was about 5 million. Based on rates of growth to that point, economists estimated England's population wouldn't reach 11 million until 2300. Instead, the country's population reached that level in 1815
By the mid-1700s, the world's population was close to 600 million. It reached 1 billion in 1800. The Industrial Revolution, better living conditions, and advances in medicine led to a population explosion. This trend of population growth continued into the twentieth and twenty-first centuries.
In 1930, the world's population reached 2 billion. It had taken more than a century for the population to double. In about 30 more years, in 1959, the world's population was 3 billion. In 1974, it reached 4 billion. The world's population reached 5 billion in 1987.
During the twentieth century alone, the world population grew from 1.65 billion to 6 billion people. As of 2015, the world's population was 7.3 billion. In 1970, there were roughly half as many people in the world as there were in 2015. This increase looks even more dramatic when viewed as a graph.
All people are entitled to certain human rights, including the right to life, the right to education, and the right to freedom. In 1948, the United Nations adopted the United Nations Universal Declaration of Human Rights. The rights apply to all people, regardless of their nationality, race, color, religion, or origin.
In spite of the declaration, human rights violations still exist in many parts of the world. The United Nations and other nongovernmental agencies monitor these violations. The broader global community also helps stop and prevent them.