Since the environmental movement began in the 1960s, one of the major problems that seems to be rampant around the world is overpopulation. The world has added one billion people every 12 to 15 years since the 1970s, and now the earth is home to over seven billion people. Some academics say this rate of growth is unsustainable. Some academics even say that the current population of the earth is unsustainable. However, many of these assumptions are overlooking key points when analyzing the population issues that the world is facing. Nevertheless, the myth that the world is overpopulated has pervaded the general conscious as part of the green movement.
One of the main reasons that there is a perception of overpopulation in the world is that most people think that population growth is exponential. The idea of exponential population growth largely began with Thomas Malthus, who originally proposed the problem of overpopulation. Working in the late 18th century in England, Malthus saw that food production in the country was increasing on an arithmetic scale while population was increasing on an exponential scale. Therefore, Malthus surmised, the population of England was unsustainable and would soon far outstrip the available food supply in the country.
Of course, this did not happen as technological advances from the Agricultural and Industrial Revolution and later the Green Revolution allowed for greater efficiency in food production. But Malthus’s idea of exponential population growth stuck with common perception. However, Malthus’ idea was flawed. Like the population growth of any biological species within its ecosystem, the growth follows not an exponential function, but a logistic function. This means that as the population approaches the carrying capacity of the ecosystem, the growth rate will decline until it becomes almost zero at the carrying capacity. There is some evidence that the world’s population has already passed the halfway point on the curve. According to the population data put out by the United Nations, the five year population increase peaked in the 1985-1990 period. During those five years, the world’s population grew by approximately 443 million people. In the five year periods before and after, the population grew by between 410 and 420 million. The growth had fallen to 389 million by the latest period, between 2005 and 2010.
The reason the world population growth is declining is because developing countries in Africa and Asia are at last entering the third stage of demographic transition as they become more urbanized and industrialized. This stage involves a fall in birth rates to match the death rate, which has already declined as improvements in public health and agricultural production have taken effect. The steady reduction in birth rates can be seen all across the developing world. India’s fertility rate has halved in the past three decades, falling from 5 births per woman to only 2.5 births per woman. In Sub-Saharan Africa, the fertility rate of the region as a whole is slowly declining, but remains at about 5 births per woman. However, there have been several successes within the region, particularly in the more developed southern part of the continent. South Africa and Botswana both have birth rates below 3 births per woman as of 2010, and Namibia’s has fallen from 6.45 in 1980 to 3.15 in 2011 and even Zimbabwe’s birth rate has fallen to 3.22 in 2011. Outside of southern Africa, Gabon has also had declining birth rates and is now at 3.22 births per woman.
The causes for these declining birth rates are many. Some of these occur naturally with a developing economy, such as urbanization. As a population urbanizes, the previous need for a lot of children to work in agriculture is lessened, while children become more of financial burden on the family. However, some of these can be directly influence by government policy. The two major factors that can be influenced by policy are access to contraceptives and great access to education, particularly for women. As women become more educated, they will have greater financial stability on their own, and may be more focused on pursuing further education or a career than on starting a family. It is these policies that are some of the major causes for the tremendous decrease in the fertility rate of many Middle Eastern countries. As a region, the MENA’s fertility rate declined from 6 births per woman in 1983 to only 2.7 now. Tunisia, Lebanon, and Iran are all at below replacement fertility rate as of 2011, and other countries such as Algeria, Qatar, and Morocco are at 2.2 births per woman, just above the replacement rate.
The declines in birth rates are all good signs of a stabilizing of the world population, but the world could still have issues with overpopulation depending on where the number of people flattens out. Current UN population estimates state that the world’s population will likely stabilize at somewhere between 9 and 12 billion people sometime in the next century, with approximately 10 billion people being the average projection. The two major concerns with overpopulation are of course access to food and safe drinking water. With food there is not much concern. The world already produces enough food to feed everyone in the world, but the issue here is that it is unevenly distributed. Additionally, food production will likely continue to increase as genetic engineering allows for greater efficiency in farm yield, and a greater emphasis on sustainable agriculture in the developed world maintains food production in those regions.
Access to fresh water, however, could pose a bigger challenge. there are many areas of the world currently going through droughts. During the summer of 2012, the United States went though the most extensive drought conditions the country has experienced in over 60 years. However, the water issue can probably be dealt with through increased use of desalinization plants to extract fresh water from the ocean. Along with desalinization, new and more accurate measurements of aquifers allows for further discovery of and more sustainable extraction of water from aquifers. In particular, the Nubian Sandstone Aquifer was recently found to hold over 150 thousand cubic kilometres of water, making it the largest aquifer in the world and a potential source of water for many countries in the Sahara region. With discoveries such as these and a larger use of desalinization, the issues with fresh water should be manageable as the world’s population stabilizes.