The Human Population and Its Growth Through History

The Average Lifespan of the Human Population

The average lifespan of the Human Population has been steadily increasing through history. During the Roman Empire, life expectancy was around twenty years. By the Middle Ages, that number had increased to thirty-three years in England, and to forty-two years in Sweden. Life expectancy has steadily increased in more developed nations to an average of 77 years today. In developing countries, life expectancy has been steadily increasing as well, and is now around sixty years in some countries.

The Population of Urban Areas

The population of urban areas is a proportion of total population, with cities of over two million people representing at least one-tenth of the global total. In 1800, most of the world's population was concentrated in Europe and Asia, with nearly fifty percent living in urban areas. However, after the Industrial Revolution in the eighteenth century, Europe and Asia became the major growth areas. The increase in Europe and Asia was largely due to immigration, with the population growth in the Americas spilling over to other areas.

The Population of Humans

The population of humans has surpassed six billion people in September 1999. As of March of this year, the world's population is estimated to be around six hundred and seventy-seven billion. And that number will continue to rise - in fact, it will likely top seven billion by 2010.

The Rate of Natural Population Growth

The rate of natural population growth is dependent on the rates of births and deaths. Younger adults are typically born with more children than older adults. This means that replacement fertility levels occur when every woman has an average of two children. But when a large number of couples give birth to only one child, it is still possible for excess births to occur. This process is referred to as population momentum. If this continues, the population will reach an unsustainable level.

Growth in the Human Population

Growth in the Human Population has accelerated significantly in the last century. Adding one billion people took 123 years between 1804 and 1930. Between 1975 and 1999, it only took 24 years to add two billion people. This means that the population will continue to rise, but the risks associated with overpopulation and damage to ecosystems and biodiversity will continue. That's why we must understand the population growth rate before it's too late. It's imperative to protect the environment and preserve the biodiversity of the world.

Short-term Fluctuations in the Growth Rate

Short-term fluctuations in the growth rate of the Human Population are linked to historical events. War, epidemics, and economic booms and busts have all contributed to a bite in the pyramid. In the United States, the Great Depression has caused a minor decline in the population pyramid, while World War I and II have created an extreme deficit in older men in Germany and England. These events highlight the interrelationship between economic factors and population change.

Growth in the Human Population in Developing Countries

Growth in the Human Population has been accelerating for decades, but the population growth is occurring in less developed countries. While Asia is likely to continue to have most of the world's population, Africa will take a bigger share. By 2050, Africa would account for almost half of the human population, while Latin America would remain at eight percent. Developing countries would still have about eight percent of the world's population. A rapid transition to a one-child policy would lead to a similar population by the year 2100. A catastrophic mass mortality event could reduce the population to eight billion people by then.

World Population Growth

World population growth is inevitable. There are three plausible scenarios for population growth, ranging from 7.8 billion people in 2005 to ten billion in 2050. Although a higher growth rate is expected for the next several decades, the current population of the Human Population will increase despite the aforementioned factors. Even the United Nations has a wide range of population growth scenarios, but three of them are quite plausible. There are many factors that will contribute to the growth of the Human Population.

Population Growth and the Environment

Growth in the Human Population has a direct relationship to the sustainability of the environment. As the human population increases, resources demand more and waste production increases. Population growth is a major problem for the planet's ecosystems. While this relationship seems straightforward, other factors also contribute to the degradation of the environment. Among these factors is the rate of female fertility. In some regions, reduction in female fertility would lead to hundreds of millions fewer people, but it is unlikely to happen in the short-term.