According to Paul Ehrlich, ‘the population bomb has detonated’. As the global population continues to grow, demand for land increases and options diminish. A rapidly expanding population burdens transport infrastructure, and the resulting surge in private vehicle ownership damages environmental health. Many large cities have water supply problems and inadequate sewage facilities, which contribute to the spread of disease. Overpopulation creates intense pressure on the environment and inhibits sustainable development.
Over two centuries ago, Thomas Malthus examined the intricate relationship between population growth and the environment within the framework of famine. He declared that while population growth is infinite, land is a finite resource. That is, population growth will exceed Earth’s capacity to provide subsistence. Thus, overpopulation leads to food availability decline, which ultimately produces famine. The number of people that can be supported by a given environment, or carrying capacity, is crucial. Malthus asserted that there is a limit to the manageable population because there is a maximum level of productivity that Earth’s land can achieve. Although Malthus underestimated the impact of technology on Earth’s capacity to produce yields, overpopulation translates into a global carrying capacity crisis which threatens to overwhelm the long-term goals of sustainable development.
The concept of sustainable development is not a new phenomenon. The term was prominently featured in Our Common Future (1987), commonly known as the Brundtland Report. The concept was given further weight when, in 1992, the United Nations Conference on Environment and Development in Rio de Janeiro created Agenda 21, a document outlining a global partnership for sustainable development. As a result, most industrialized nations have designed a sustainable development strategy. The Brundtland Report defines sustainable development as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’ (WCED, 1987). This definition implicitly highlights the tension between the crucial concepts of human needs and limits, and sets out the principles of intergenerational and intragenerational equity. Emphasis is given to the essential needs of the world’s poor because poverty and resource disparities are seen as significant causes of environmental ruin. The notion of limits requires that humans must moderate demand on natural systems in spite of their immediate needs. Overpopulation effectively increases demand on natural systems, thus placing constant detrimental pressure on the environment.
Sustainable development is a multi-faceted concept, and its meaning is often contested. Several different versions of sustainable development have emerged. The continuum of sustainability levels varies according to the ways in which human and environmental resources are valued. The amount and degree of substitutability of human capital for natural capital is controversial. Very strong sustainability assumes no substitutability. All elements of natural capital must be preserved. Strong sustainability only allows for the depletion of natural capital when it is compensated for through rejuvenating processes such as reforestation, or by social improvements. Weak sustainability conserves certain critical natural processes deemed essential to life, such as rainforests, but allows for substitution of other types of natural capital. Finally, very weak sustainability assumes infinite substitutability so that declining natural resources are compensated for by human capital. The flexibility suggested by such a wide range of definitions makes sustainability an often challenging policy objective, which is made only more difficult in times of overpopulation.
Ideally, sustainable development widens choices for all people, while preserving the environmental systems on which all life depends. The Brundtland Report directed attention to the wider political and social issues that exist within the context of sustainability. Similar to other political views, such as justice, sustainable development is a positive force with broad boundaries. The cornerstones of sustainable development are the principles of democracy and equitable distribution. An atmosphere of active participation and democracy is conducive to sound policy. It is vital that all interests, whether poor or rich, participate in planning and decision-making.
The Brundtland Report also highlights another important relationship: ‘ecology and economy are ever more interwoven – locally, regionally, nationally, and globally – into a seamless net of causes and effects’ (WCED, 1987). The struggle to survive in the poorest countries inflicts huge pressures on natural resources. Agricultural development programs have effectively promoted the production of harsh cash crops in order to optimally increase foreign earnings. Production of cash crops, at the expense of food security, creates havoc on precious land. The resulting resource depletion perpetuates a downward spiral of impoverishment by forcing more people onto fragile lands. This spiral is accentuated in the Philippines, where the combination of overpopulation and scarce land led to ‘uncontrolled deforestation’ (CIA, 2006). The result has been erosion, water shortages, and extreme poverty, much of which is irreversible. Poverty hinders the ability to use natural resources in a sustainable manner. A world ‘in which poverty is endemic will always be prone to ecological and other catastrophes’ (WCED, 1987).
Sustainable development is concerned with identifying environmental limits, meeting basic needs, and equity. By highlighting a complex system of political, social, economic, and environmental trade-offs, the Brundtland Report taught us to analyze sustainable development not as a static structure, but as a dynamic process. The economy and the environment are mutually interdependent. Unfortunately, a thriving and sustainable environment is challenged by a world marked by overpopulation.
Central Intelligence Agency. The World Factbook – Philippines. 2006. [http://www.cia.gov/cia/publications/factbook/geos/rp.html]
WCED. Our Common Future, Oxford University Press. 1987.
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