Population Bulletin, Vol. 53, No. 1, March 1998
by Robert Livernash and Eric Rodenburg
The Earth's resources, natural systems, and human population are inherently connected. The fundamental relationships are fairly easy to grasp: People rely on food, air, and water for life. The Earth's resources provide energy and raw materials for human activities, and those activities, in turn, have an impact on the Earth's resources and systems.
The simple act of an individual lighting a campfire has environmental implications in terms of resource use (the wood used to build the fire), energy (the heat created by the fire), pollution (emissions of ash and carbon dioxide), and waste (carbon and ash left after the fire has burned out).
Assessing the impact of such an event requires several lines of inquiry: Was the fire lit in an area with abundant or scarce wood resources? How many other people light fires in the same area? Have some people figured out a way to burn wood more efficiently, thus reducing the need for the resource? Do some people have sufficient resources to burn a fire continuously, while others can only burn a fire at night? If wood is being consumed faster than it is being replaced, when will the resource be exhausted? Was the wood from a rare species of tree?
The impact of human activity on the environment was negligible 3,000 years ago when less than 100 million people inhabited the planet. But the collective impact of the 5.8 billion people living on the Earth today is tremendous.
Human interaction with the environment — resource use, consumption, pollution, and waste — involves the same processes today as it did at the dawn of human history, but the scale and complexity of these human activities are vastly greater. And the pace and magnitude of population growth over the past century, and the projected growth in the next century, are unprecedented in human history.
Now, as never before, government policies may increase (or reduce) resource use, consumption, and environmental change, and humans can devise new ways to accommodate their needs with less impact on the natural environment.
Assessing the connections among population, resources, and environment is a complex and frustrating exercise, marred by differences in approach, the biases of different methodologies, and the complexity of the linkages.
There is a basic philosophical division in the study of population and environment that is often characterized, or perhaps caricatured, as a debate between optimists and pessimists. Optimists believe that people have the creative capacity to overcome potential environmental harm resulting from a growing population and intense economic activity. Pessimists foresee potential political, social, and environmental deterioration and collapse.
Optimists can point to the general improvements in human health and life expectancy, rising per capita incomes, remarkable advances in food production, and technical innovations that can reduce environmental pollution or improve the efficiency of economic activity. Some see population growth as a stimulant to human innovation and genius.
Pessimists make their case by pointing to rapid world population growth, the growing concentration of carbon dioxide in the atmosphere, the declining health of the oceans, reductions in biodiversity, and degradation of land.
A second major division in the debate involves the frame of reference for investigating population-environment linkages. Some investigators seek to manage Earth's resources and ecosystems to benefit humans, while others strive to minimize human impact on the Earth.
Finally, these differences in philosophies and frames of reference influence the debate about how best to reduce the stress of human activity on the environment. Are better policies, different political or economic systems, new technologies, or changes in lifestyles the best way to protect the environment?
People and nations have an array of choices about the way they live and do business. They can choose to reduce their negative impact on the environment and move toward sustainable development. The apparent willingness of people to recycle solid waste and the willingness of governments to develop programs to protect the environment, for example, suggest that people and governments can make remarkable progress toward more sustainable development. But we need to understand more about the basic relationships to justify individual sacrifices in quality of life and to shore up the political will necessary to enact policies to protect the environment.
This Population Bulletin explores the debate about the contribution of population and consumption to resource use and pressures on the natural environment. The report examines predictions about the consequences of population growth and the extent to which government policies might alter outcomes.
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Introduction