Is Human Population Growth A Threat Environmental Sciences Essay

Even though population is often considered a sensitive topic, it is becoming increasingly difficult to ignore the concept that population growth threatens the environment. The rapid increase in population growth over the past few centuries has led to an increasing interest in, and a growing concern for population growth as one of the key threats to the environment. A threat to the environment can be in many different forms, such as soil erosion, climate change, deforestation, wastes, and pollution. The aim of the following essay is to explore how population growth is considered to contribute to these issues and degrade the environment. In order to achieve this aim the essay will be split into two main parts. The first section will outline theories that argue population growth is a threat to the environment. This will be supported by Malthus and Meadows et al. In order to gain a succinct analysis this essay will concentrate on the natural environment, in particular exploring how deforestation is threatened by population growth. However, the second part of the essay will challenge this and purport that population growth does not endanger the environment. It will argue that an increasing population could improve environmental quality. It also will claim if resources are managed sustainable then population growth will not negatively affect the environment. This is supported by Tiffen and Mortimore and Fox. Local case studies are used as micro studies show the relationship between population and deforestation more clearly, as macro studies are affected by many other influences. Finally the conclusions reached are population growth is not the root cause of environmental damage. If resources are managed sustainably and new technologies are used, then population growth itself would not threaten the environment.

A positive correlation between population growth and environmental damage

“Overpopulation [is] our number one environmental problem” (Rodnguez-Tnias 1994:1379).

Since 1650 the rate of population growth has increased. This has resulted in a rapid increase of the world population which “rose from 3.3 billion in 1965 to over 6 billion by the year 2000”. Thus world population almost doubled in just 35 years and the rate of growth itself was also rising. Moreover a billion people were added to the world population from 1987 to 1999, an increase equivalent to the total world population in 1804 (Panayotou 2000). This relatively recent increase in world population has led to a mounting concern for how population growth affects the natural environment and natural resources (Meadows et al 2005:28). There are many reasons as to why population growth is seen as a threat to the environment. For example, human populations use up natural resources, omit greenhouse gases contributing to climate change, destroy habitats resulting in loss of biodiversity, and increase air and water pollution levels. Hence, almost all environmental issues are either directly or indirectly related to population. Furthermore, it is often reported in the media that a growing population is an environmental threat, further increasing the concern. For example Andrew Woodcock reports in The Independent that a “booming population is a threat to climate change” (2006 online). There has been a simultaneous trend of a growth in population and a steep decrease in environmental quality and an increase in resource depletion (Panayotou 2000).Consequently, population growth is often considered the greatest and key threat to the environment.

The debate on the correlation between population and the environment began over 150 years ago when classical political economists such as Malthus (1798) identified a relationship between population and food supply. He argued that population grew exponentially, whereas food supply would only grow arithmetically, resulting in major food shortages. He claimed that the pressure on agricultural land would result in a decline in environmental quality, forcing cultivation of poorer quality land. He criticised the idea that agricultural improvements could be made and expand with limits and claimed that the power of population growth was greater than the earth’s ability to support man. Malthus concluded that population growth must limited to remain within environmental restrictions, as the earth’s resources are finite. Malthus’ theory that the size of population is dependent on food supply and agricultural methods,

This idea was resurrected in the 20th century, by key publications, most notably The Limits to Growth by Meadows et al (1972) and The Population Bomb by Ehrlich (1968). This new body of work by contemporary authors is referred to as neo-Malthusianism. The debate however has shifted from agricultural land to concerns about the role of population growth in the depletion of other natural and renewable resources, and the effect of population growth on climate change and on biodiversity loss. Meadows et al (1972) argued that population growth can create problems because of environmental limits. They argued that population growth cannot continue indefinitely and used past data to predict future trends in world population, resource depletion, pollution and food production. They claimed that the limits of the planet will be reached within the next century and that population could therefore not carry on growing. In their 30 year update in 2005 they argued their conclusions were even more important today. They claimed that there is now land scarcity and the limits have been approached, which is especially serious as population keeps rising and resources are being depleted. Growth in the globe’s population could lead to the possibility for a potential catastrophic overshoot (Meadows et al 2005). Livi-Bacci (2001) points out that in Bangladesh the limits have already been reached, hence population cannot carry on growing. This is similar to Ehrlich (1968) who argued that there should be action to reduce population growth otherwise there would be mass starvation. The growth of world population increases the demands on natural resources, making it difficult to protect these resources, thus declining environmental quality (Sitarz 1993). Hence there are reasons to worry about the effect population growth will have on the environment in the long term (Sen 1994). Consequently the consensus is that there is a “population problem” (Neumann 2004:817).

Population growth causes problems in the local environment. There is no single guide to analysing the state of the environment; therefore the relationship between population and environment is usually evaluated in terms of individual resources or measurements of environmental quality (Panayotou 2000). Environmental quality can be measured by the stock of forests or by the absence of air and water pollution. The affect population growth has on deforestation has received considerable attention as forests play a key role in wildlife habitats, the carbon cycle, and a source of raw material. At the global scale deforestation contributes to global warming, and at a local scale leads to soil degradation (Fairhead and Leach 1995, Nyerges and Green 2000).

There is evidence which supports Malthusian arguments that an increasing population has a negative effect on environmental stocks. The role of population growth is particularly clear in fragile environments such as forests (Livi-Bacci 2001). The cause of deforestation is frequently seen as a result of population pressures as population growth increases the need for arable land, resulting in a conversion of forest land to other uses (Cropper and Griffith 1994). Malthus argued population growth would result in a higher need for agricultural land and this results in a decline of forest land particularly in Africa and Latin America (Livi-Bacci 2001). 60% of the world’s deforestation is a result of the need for more agricultural land (Pimentel and Pimentel 1999). Each year, “70 million people are added to world population, mostly in developing countries and 15 million square kilometres of forests disappear”(Panayotou 2000:25). This research led to many people hypothesising that more people must result in fewer forests, as the higher the population growth, the faster this process will take place (Ehrlich and Ehrlich 1990, Rudel 1991). This will cause a steep decrease in forest size from year to year. Forests frequently owe their origins to depopulation, therefore resulting in the conclusion that population growth causes deforestation, especially in poor and developing countries (Fairhead and Leach 1994). This affect is more observed at the local level, for example Cropper and Griffith (1994) used panel data for Asia, Africa and Latin America between 1961 and 1988 and found a positive relationship between deforestation and population growth. Additionally, Fairhead and Leach (1995) identified that there was an observed decline in forests in The Ziama Forest Reserve in Guinea as a result of growing populations, which have moved away from “traditional” methods. IUCN report on Ziama states that “forest cover in this part of Guinea is now only 20% of what it was ‘at origin'” and the report emphasizes that the forest is regressing rapidly (cited in Fairhead and Leach 1995:1029). Therefore the decline of forests reflects the populations who cleared it (Fairhead and Leach 1994). Furthermore Sambrook et al (2004) did a study of 450 traditional hillslope farms in the Dominican Republic, and found there was positive relationship between population pressure and deforestation. They found that for the entire 1987 farm sample, “52% of the variation in deforestation is explained by population pressures” (p36). This effect can also been seen at the country level, for example in Thailand deforestation was caused by demographic pressure from migration (Livi-Bacci 2001). Consequently, “population growth causes a disproportionate negative impact on the environment” (Ehrlich and Holdren 1971:1212).

There is a conventional wisdom that population growth is responsible for deforestation. This supports the neo-Malthusian view that population growth is the root cause of environmental degradation, and growing demands for finite resources. Therefore the solution is direct population control (Panayotou 1996). If population growth is a major threat to the environment then steps must be taken to reduce the rates of growth. Livi-Bacci (2001) argues that a decline population increase will diffuse the issue of the environment. Therefore “there is an immediate need to develop strategies aimed at controlling world population growth” (Sitarz 1993:44). This means that there needs to be support for family planning throughout the world especially in developing countries which have the highest rates of population growth, and less access to family planning (Barlett 1994). Therefore, slowing the increase in population, especially in the face of rising demand for natural resources, can help protect the environment. As population size reaches even higher levels the environment is at risk and the outcome is impossible to predict, therefore policies to reduce population are needed (Upadhyay and Robey 1999). However, the next section will counter this and argue population growth is not a threat and therefore there is no need for population controls.

Population growth is not the key issue for threats to the environment

There is scepticism about whether population growth is the key threat to the environment, as Monbiot (2008 online) writes “is population really our number one environmental problem?” Even though there is evidence of a correlation between population growth and a decrease in environmental quality, a nearly perfect correlation does not necessarily imply causation. Otherwise, it would be expected that countries with the highest population such as China and India would have the highest use of natural resources (Panayotou 2000). The worldwide average per capita use of forest resources is 0.75 ha, whereas in China, a country which approximately 20% of the world population uses less that average forest resources with only 0.11ha/capita (Pimentel and Pimental1999).

Some problems have been raised over the Malthusian view of population growth threatening the environment. The world has coped with fast increases in population, even though Malthus predicted terrible disasters. At the time he wrote there were fewer than a billion people in world but he felt the earth’s limits had past. The world population has grown six times larger since 1798, but contrary to what Malthus predicted, food production grew even higher (Sen 1994). Clearly, Malthus (1798, 1803) did not foresee the technological advances of the last two centuries as a result of the industrial and agricultural revolutions. Like other classical writers he assumed that land productivity was fixed (Panayotou 2000). Boserup opposes Malthus’ theory arguing that agricultural methods depend on population size (Darity 1989). Boserup (1965) theorised that population determined agricultural methods, therefore the power of initiative and new innovations would overcome the power of demand. This means population growth would not continue to degrade the environment as communities would switch to new and more intensive methods of the land. Thus population growth does not result in a degradation of the environment because populations will change to another system with a higher carrying capacity. Therefore, “the issue is not the numbers of people, but how those numbers relate to available resources” (Barlett 1994:9). Technological changes and better management of resources would ensure that a population can expand the earth’s capacity. It can be argued that population growth is in fact the driving force for efficiency and technological innovation ensuring growth without damaging the environment (Panayotou 1996). For example an increase in agricultural yields can offset the effect of population growth on deforestation as a 10% increase in agricultural yields from technological change would result in a 1.1% reduction in deforestation (Panayotou 2000). Therefore the effects of population growth can be reduced by modern technology and increased efficiency (Cropper and Griffiths 1994). Consequently, an environmental crisis can be avoided if steps are taken to conserve and manage resources and demand sustainably (Upadhyay and Robey 1999). Therefore the natural environment and resources has never been fixed but has expanded due to innovation. The limits to growth are not defined as they are connected to the effects of technological growth and cultural choices (Livi-Bacci 2001). This rejects Malthus’s argument as he assumed land productivity was fixed, whereas Boserup (1965, 1976) argues that famine is not possible as technological changes would allow food production to keep up with population growth. In addition, more efficient and environmentally sound agricultural technologies must be developed and put into practice to support the continued productivity of agriculture (Pimentel and Pimentel, 1996).

Meadows et al (1972) and Ehrlich were wrong to suggest population growth would lead to environmental degradation as it may result in conservation or an improvement of the natural environment. This view does not restrict the levels of population but suggests it can actively improve the environment. Tiffen and Mortimore (1994) argued against Malthusian views and pointed out that population growth does not necessarily threaten the environment as better management and investment would ensure the natural environment is protected. Agricultural labour requirements increased not because of a larger amount of cropped land but because of larger labour requirements, as Boserup suggests. They pointed out that an increasing population would increase access to sources of knowledge and using technologies. This enables outputs to rise faster than population growth. Like Tiffen and Mortimore, Murton (1999) also argued against Malthusian arguments. He used example in the Machakos district in Kenya which showed that environmental conservation occurred during periods of population increase. Therefore, population growth is an important means of improving environmental quality. Therefore, if resources are management sustainably then population growth can protect the environment. He found population growth has a positive influence on forests as farmers became more dependent on non-agricultural sources of income. Therefore, Malthus is wrong to suggest there would be a catastrophe as population increase can have a positive influence on forests. This is supported by Fox (1993) who did research on forest resources in a Nepali village Bhogteni in 1980 and 1990 and found “despite an annual population growth rate of 2.5%, forests were found to be in much better condition in 1990 than they were in 1980” (p89). Thus population growth had a positive influence on forest resources. He found that Nepali farmers began to develop their own methods for conserving the forests through community management. This result in an increase of forest resources as in 1980 private woodlots had 179 trees/ha compared to 489 trees/ha in 1990. Therefore population growth does not necessarily lead to downward spiral of land degradation. Fairhead and Leach (1994) also identified a counter-narrative for their evidence, as local residents argued they had created the patches of forest around their villages, not destroyed it. Oral history suggests that the villages encouraged and managed the growth of forest islands around their villages. Therefore, it is not necessarily the case that the area was originally forest prior to increase of the population. It is conceivable that management of the local resources was partially responsible for the spread of forest areas, from earlier savanna-like conditions. They point out that more villages actually resulted in more forest islands. The Ziama region was originally bare rock not forest land. Therefore there is a broader narrative (Fairhead and Leach 1995). Therefore the wrong interpretations were made based on stereotypes (Fairhead and Leach 1994). Conversely, oral history is not fact, or based on empirical evidence and can’t apply these local/village findings everywhere. Hence the validity of these arguments is questionable. While this rejects Malthusian arguments, as population growth did not lead to further environmental degradation, it does not confirm Boserup’s hypothesis that population growth would lead to new innovations.

Furthermore, population growth creates the incentive to protect the environment, as costs of existing resources increase and benefits from substitutes are realised (Panayotou 2000). Therefore the rapid population growth in Bhogteni may have resulted in an increased willingness of the villages to seek better management for forest lands. Thus forests would not have been perceived as threatened if there was not a high population growth rate. Fox (1993) also argues that other variables contributed to the management of the forest in Bhogteni, such as an introduction of a new road and changes in forest tenure. Nevertheless, while population growth can trigger land use changes it is not the root cause of environmental damage. The root cause results from market failures, especially in developing countries where property rights are neither defined nor enforced. Thus the private cost of deforestation is zero. Therefore, because they have no right of ownership to the land they have no incentive to protect it and make efficient land-use decisions (Panayotou 2000). We should recognize, however, that the immediate threat to these lands is not population growth but bad forest management policies. Before population can be cited as the cause of forest degradation, forest policies must be implemented that provide incentives for local people to manage forest resources (Fox 1993). It is often the conclusion that population drives deforestation, however, the context must be kept in mind, such as open access forest resources, low levels of education, insecurely held agricultural land. These all combined prevent response to population growth. Therefore a more complete analysis should look at all these factors. Furthermore, other issues also affect the rate of deforestation. Holdren (1991) used a mathematical formula I = P x A x T to show how population, affluence and technology have an impact on the environment. He claimed that environmental policies should focus on consumption rather than population growth. Population growth is a factor among other issues. While the Brundtland Report (1987) states that population growth is not the central problem. Furthermore, if a country has a higher income then the rate of deforestation is likely to be slower. As income rises, people use other energy sources and modern agricultural techniques which reduces the demand for agricultural land. Therefore reducing the rates is population growth is not necessarily the best method for decreasing the rate of deforestation (Cropper and Griffiths 1994). Therefore all of these factors are responsible for a deterioration of the environment and all need to be tackled. Therefore population is only one factor among many, and the interactions of these factors are crucial for driving the deforestation process. Policies are needed to tackle poverty in developing countries and high consumption levels in developed countries first (Saxena and Nautiyal 1997).

However, it depends what level is being studies as micro studies may find significant negative effects on resources from population pressures on the local environment, while macro studies identify no resource constraints at the national or global level. This distinction between ‘macro’ or aggregate, analysis and micro, or more disaggregated analysis is one that you could develop further. One of the points that this leads to is questions of control of resources and the uses to which they are put. Macro-level and micro-level analysis may lead to different insights and conclusions in this regard. Micro studies-even though better analyse the effect of population growth also mask the wider socio-economic factors which may result in environmental degradation (Murton 1997). Therefore there are complications for tracing the effect of world population on the global environment (Panayotou 2000)

The interlocking crises in population, resources, and environment (Ehrlich and Holdren 1971).

“The Malthusian theory of population growth and resource degradation is clearly a myth that needs to be slain.p97” (Fox1993).

Conclusion

From examining the evidence above it is clear that there is little agreement on the relationship between population and environment, there is a tremendous variation in findings and their interpretation. The selective use of evidence gives rise to outcomes that range from the most pessimistic to the most optimistic.

The objective of this essay was to review analytically and critically the arguments on the population-environment interface. This essay has outlined Malthusian arguments of population growth causing environmental degradation. This essay has also explored counter-evidence to this, arguing that innovation and a better management of resources can offset the effects of population growth. This essay has also argued that other factors affect are the cause of deterioration in environmental quality. A more complete analysis should incorporate these factors and their interaction with population growth. It is generally agreed that population growth is an indirect threat to the environment. Therefore direct threats need to be addressed. Issues such as poverty need to be solved to improve environmental quality, not reducing population numbers.

However, whether evidence is used from macro or micro scales can skew the results.

To conclude that much more empirical research, with more sophisticated models, is necessary before we can fully understand the role of population dynamics (density, growth, distribution and composition) on deforestation.

Java’s population quadrupled in the last 100years. However, environmental damage was due to economic reasons not population growth. Failure to improve agricultural productivity and to create non-agriculutral employment has intensified population pressures. Panayotou (1996).