Biosphere in Distress

Article excerpt

The widespread degradation of landscapes, loss of biodiversity, and pollution of air, water, and soil have weakened our life-support systems and placed our planet in critical condition.

"To health and prosperity!" So goes a commonly heard toast. Indeed, good health and adequate wealth are among the desirable goals of most people. Yet many of our actions seem to be turning our future away from these goals. In our zeal to achieve immediate economic prosperity, we have compromised the health of individuals, populations, and ecosystems, and we have depleted the wealth of our natural resources.

In the late eighteenth and early nineteenth centuries, Rev. Thomas Malthus of England was among the first to sound the alarm that the human population would outstrip its food supply and become trapped in menial subsistence. Then came the Industrial Revolution, and new agricultural methods allowed the production of food to rise dramatically, forestalling the Malthusian predictions of doom in much of the Western world. Malthus was regarded as having been mistaken.

On the other hand, the population booms in Asia and Africa have greatly aggravated the problems of poverty, nutritional deficiency, and inadequate hygienic facilities there. Today, despite the "green" revolution, two-fifths of the world's population of six billion suffer from chronic malnutrition. Nearly half the total population live on a per-capita income of under two dollars per day. In addition, 1.3 billion people live without clean water, 2 billion without proper sanitation, and 2 billion without electricity. It is only from the perspective of the economically privileged that the world looks rosier.

Nonetheless, the ramifications of biospheric degradation will be (and in some instances are being) felt by all people, rich or poor. With this realization, governments and international bodies have come together to upgrade efforts to improve the environment. James Wolfensohn, president of the World Bank, has stated that "responses to global environmental issues are not fringe activities. They are central to meeting human needs and reducing poverty."

The first step to an adequate response is an appraisal of where we are today. What is the state of the biosphere and its ecosystems? By what criteria can their health be assessed? What are the sources of stress? What are the opportunities to turn things around? These questions are now being addressed by national and international organizations, private groups, academics, and citizens and communities around the world.

One common ground in these discussions is the need for a more integrative approach to environmental challenges--one that takes into account the relations between the biophysical, social, psychological, economic, ethical, and political dimensions. As is often said, we have only one earth--and all these aspects must be seen as part of a whole.

What constitutes ecosystem health?

In 1935, Alfred George Tansley coined the term ecosystem, in referring to an integrated system of plants, animals, and their environment, including the myriad interactions between them. Ecosystems are "open systems," but they are bounded in physical space, often in terms of local or regional landscape features. For example, ecosystems can be forested, prairie, mountainous, coastal, estuarine, and so on.

Tansley considered ecosystems as part of the grand hierarchy of nature-- from the atom to the universe. The term biome, referring to a larger biotic community of plants and animals, may be seen as the next step up in the hierarchy. Biomes in the Arctic, for example, consist of such distinct geographical regions as the tundra (polar desert), taiga (cold coniferous forest), cold deciduous forest, and cold mixed forest.

The biosphere stands at the top of the hierarchy of living systems. First proposed by the Russian geoscientist Vladimir Vernadsky in 1926, the concept refers to the thin layer of our planet between the lithosphere and the stratosphere--the layer where living organisms exist and interact with their environment. …