Planet Earth's Capacity (Essay Sample)

Planet Earth’s Capacity
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Planet Earth’s Capacity
Planet Earth is the fifth largest among the nine planets, and among the few that can support life. It is the sole planet that contains water in liquid form with 71% water coverage, a fact that gives it the ability to support life since water is essential for life. It can support human, plant and animal life since it is well supplied with essential gases such as 77% nitrogen, 21% oxygen, water, and carbon dioxide and argon in small quantities. Thus, planet Earth supports a significant number of people (Cohen, 1992).
The human population has continually increased since the inception of life on Earth about two hundred years ago. The human population started at about 100 million, and by 1850, the number had reached one billion. Statistics show that the number of people inhabiting the Earth doubles up, in every 100 years. Initially, it took about 150,000 years for the population to strike one billion, but the growth rate has tremendously increased over the centuries. The United Nations projected that the estimated number of people on Earth by 2300 will be 9 billion depending on factors such as fertility and longevity of life. Various eminent scientists across the have also proposed their projections with some arguing that the planet can sustain 1000 billion people. Other scientists such as Edward O. Wilson base their estimations on the presence of supplies such as food and water on Earth (Wolchover, 2011).
The size of arable land on earth is estimated to be about 3.5 billion acres, with an annual production of about 2 billion tonnes of grain. Assuming that all humans were vegetarians and holding all other factors constant, the land can sustain about 10 billion people. This is when only humans feed on the grain grown on the land excluding livestock and other creatures. However, this is not realistic since humans are omnivorous and they coexist with other creatures such as livestock, and they share the resources on the land. Other factors such as availability of minerals and gases essential for human sustenance limit the Earth’s carrying capacity; thus, reducing the number of people that Earth can support (Radford, 2004).
The United Nations Population Division estimated that the human population is bound to increase to 7 billion by 2014 and could rise to 9 billion by 2050. Thus, by 2100, there will be about 10 billion people living on the Earth. The population is likely to stabilize at 9 or 10 billion people since there is a fertility decline leading to smaller families. Every woman is siring about 2.1 children, and the fertility rate is said to have reached replacement level. The Earth’s capacity to support human life is at its maximum and cannot stretch any further depending on the available resources. Therefore, by the end of the century, the population could level and stabilize at the 10 billion mark (Wolchover, 2011).
With planet Earth as the fifth largest am...