The idea of carrying capacity

‘By the end of the 21st century, human population growth may exceed Earth’s carrying capacity’. Discuss.

The idea of carrying capacity is not a new one. Carrying capacity is the maximum population size that the environment can support without deterioration (McGraw-Hill, 2002). The first idea of carrying capacity applied to natural organisms was introduced in the 1980’s so the concept that the earth is a ship with only enough food and resources to be able to sustain a finite population is not new (Sayre 2007).

The population of Earth currently stands at around 6.8 billion and is expected to reach 7 billion by the year 2011. In just 12 years, the population of earth has risen by nearly 1 billion after a population of 6 billion was reached in 1999 (Unknown 2009). Population has been projected; and estimated to reach 9.4 billion by 2050. (Ehrlich.P, A 2009). The rate at which population is increasing causes a growing concern with the carrying capacity of the planet and whether or not the planet will be able to sustain the population.

Humans have already put strain on the environment and an increasing population puts an ever-growing strain on the environment. Human and environmental changes that need to be considered such as climate change and over-consumption, new industrialising countries such as India and China. Countries with rapid population growth are already finding it hard to improve, or even maintain the health of their people and their economies. (MacKenzie 1994).

There are many people who believe in Ester Boserup’s view that human innovation and ingenuity will prevail and overcome any problems that pose a threat to mankind. There have been many technological advances, which has allowed for increased yield of crops, one such advance is the invention by Fritz Haber in 1909, the nitrogen fixing process known as the Haber-Bosch process (Matthews 2005). This process has helped feed many millions and saved them from death and starvation (Bhagwati 1996). Many other technological advances such as one from Norm Borlaug where he devised a system to accelerate the breeding of disease-resistant wheat and beat the stem rust fungus in Mexico (MacKenzie 2009).

The gains have not been without cost: soil quality has been damaged, crops like bananas have become less genetically diverse, rare breeds of animal have been pushed close to extinction, and habitats have been destroyed. Increasing demand for meat also puts pressure on agriculture (Marshall 2009).

However factors such as climate change that may lead to rising temperatures, which is accelerated by our over consumption causing massive amounts of pollution and use of valuable resources is of great concern to the worlds carrying capacity and even with the advances in technology that humans succeeded in the future still looks grim.

The six most widely grown crops in the world are wheat, rice, maize, soybeans, barley and sorghum. Results suggest that yields of maize, cotton and soybean drop by roughly 0.6 per cent for each “degree-day” spent above 29 °C. At present, agricultural regions across the US spend an average of 57 degree-days above 29 °C during the growing season. A growing season could rise to 413 degree-days by the end of the century (Barley 2009). As early as 2020 several countries in Africa are likely to experience a reduction in crop yields by up to 50%. Droughts in Kenya have become 4 times more common in the last 25 years. In 2009, Kenya has had its third failed harvest in a row. (Alagiah 2009)

Overfishing of the world’s oceans has also led to great damage, causing population crashes in many species although in recent years, fish farms have become more widespread and they reduce the burden on wild fish but have problems of their own with escaping fish, excessive food consumption, infectious viruses and louse infestations (Barley 2009)

The problem of increasing population makes the situation much more difficult to manage. It may be possible that human innovation and ingenuity will overcome any difficulties that mankind faces, although it does seem that the limit of the planets carrying capacity is close to reaching it’s peak; with depleting reserves of minerals, oil, agricultural yields and loss of biodiversity and that along with environmental changes in the world it will be difficult for the entire planet and that carrying capacity is a subject that needs careful consideration today.

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