The World Population

(I) Introduction

The world population has been rising at an alarming rate. According to the prediction made by the Population Reference Bureau, the world population could reach 8.1 billion by year 2025. Despite the existence of different schools of thought on the population growth problem, the majority agrees with the more cruel fact that increasing human activities, as a result of growing global population size, do lead to depletion of resources, pollution problems and degradation of environment. A proper control in human population growth is urgently called for by different parties around the globe. The relationship between the world's population growth, human use of resources, and global environmental crisis will be examined thoroughly in this essay.

(II) An overview of the world's population growth

It may be abstract to describe the population growth as drastic and alarming without providing any evidence to prove. The graph below shows the change in population size from Old Stone Age to now and the prediction of population size until 2100. It can be observed that the growth was actually very slow for thousands of years. Over a million years were taken for the world population size to reach about 1 million by the beginning of the 19th century. However, the growth speeded up afterward. A second billion was added in the next 130 years, a third in the next 30 years, and the fourth billion in just 15 years (McNamara, 1992). Now there are 7 billion people in the world. It is predicted that the world will have a population size of 8.1 billion people in 2025 and 9.4 billion in 2050 (Population Reference Bureau, 2010). A J-curve can be observed from the graph. Such a rapid exponential growth of population or what we called "population explosion", if not controlled properly, will probably lead to a big catastrophic event, which in turn reduces human population.

What are the reasons behind such a phenomenon? Decline in death rate, due to improved medical condition, health care system, hygiene and food production skills, is one of the prime reasons behind that. In the old days, diseases can easily kill people massively, examples are Black Death, smallpox, influenza, etc. The death rate and infant mortality rate were high. With a great medical advancement in recent decades, most minor diseases can be cured completely and even patients with severe illnesses also have the chance to survive. Inventions like vaccines and antibiotics contributed largely to the control of widespread of diseases. Apart from that, the number of people died due to starvation and malnutrition has also been significantly reduced because of the modern agricultural practices which enhance the production and nutrition value of food. There are still numerous factors which contributed to population growth. But what we cared most is how the population growth and the increase in consumption of resource are related.

(III) Human use of resources

The tremendous growth in population leads to environmental crisis mainly by increasing demands for food, energy, water and natural resources. Urbanization is found to be accelerated in many countries due to increase in population. Urbanization creates pressures on the environment, particularly where they occur in ecologically vulnerable ecosystems (UNFPA, 2001).

In order to cater for the growing demand for food, water, housing and consumptive goods, increased agricultural, industrial and commercial activities are found in many countries. These activities are often wasteful and destructive to environment due to human misbehavior, like deforestation for intensive agriculture and overgrazing, combustion of fossil fuel for industrial uses, over tapping groundwater, etc. In both rich and poor countries, the negative effects on the environment are combined with inadequate development policies and mismanagement of resources by the government (UNFPA, 2001). Resources such as potable water, agricultural viable soil, fossil fuel are under the threat of depletion. People's attitude toward resource conservation is also an influential factor. Many people are not self awareness enough about what they are doing to the planet they live in. They used to believe that resources are unlimited despite the fact that many resources like fossil groundwater and fossil fuels are actually fixed deposit and are vulnerable to depletion. Excessive consumption is resulted in because they seek for a materialistic life style as they become increasingly affluent. This is common in More Developed Countries (MDCs), whereas people consume resources mainly for satisfying basic needs like food and shelter in Less Developed Countries (LDCs).

The use of the term excessive consumption calls for its definition. Consumption of world resource is considered as excessive if it exceeded the carrying capacity of the Earth. Ecological foot print is a good concept to demonstrate human demands on Earth's natural capital. It measures the extent of human demand for the regenerative capacity of the biosphere. As at year 2007, humanity uses the equivalent of 1.5 planets to provide the resources we use and absorb our waste. This means it now takes the Earth one year and six months to regenerate what we use in a year. Moderate UN scenarios suggest that if current population and consumption trends continue, by the 2050s, we will need the equivalent of almost three Earths to support us. But the truth is that we only have one Earth. Turning resources into waste faster than waste can be turned back into resources puts us in global ecological overshoot, depleting the very resources on which human life and biodiversity depend (Global Footprint Network, 2012).

(IV) Global environmental crisis

Such a global ecological overshoot causes various environmental problems over the world. Pollution is an overwhelming problem worldwide caused mainly by human extraction and use of resources. There are numerous sources of pollutant which lead to environmental degradation. Water bodies such as lakes, streams, oceans, and groundwater are polluted with sewage, industrial waste, detergent, fertilizers, heat and plastics. Carbon dioxide, nitrogen oxide, and sulfur dioxide are emitted to the atmosphere by burning of fossil fuel. The use of nuclear power has also result in the accumulation of radioactive waste, posing