Introduction to Sustainability
This section introduces the concept of sustainability, which refers to the sociopolitical, scientific, and cultural challenges of living within the means of the Earth without significantly impairing its function.
Taking The Long View: Sustainability in Evolutionary and Ecological Perspective
Of the different forms of life that have inhabited the Earth in its three to four-billion-year history, 99.9% are now extinct. Against this backdrop, the human enterprise barely merits attention with its roughly 200,000-year history. As the American novelist Mark Twain once remarked, if our planet’s history were compared to the Eiffel Tower, human history would be a mere smear on the very tip of the tower. But while modern humans (Homo sapiens) might be insignificant in geologic time, we are by no means insignificant regarding our recent planetary impact. For example, a 1986 study estimated that 40% of the product of terrestrial plant photosynthesis — the basis of the food chain for most animal and bird life — was being appropriated by humans for their use. More recent studies estimate that 25% of photosynthesis on continental shelves (coastal areas) is ultimately used to satisfy human demand. Human appropriation of such natural resources profoundly impacts the wide diversity of other species that depend on them.
Evolution normally results in the generation of new lifeforms at a rate that outstrips the extinction of other species; this results in strong biological diversity. However, scientists have evidence that, for the first observable time in evolutionary history, another species — Homo sapiens — has upset this balance to the degree that the rate of species extinction is now estimated at 10,000 times the rate of species renewal. Human beings, just one species among millions, are crowding out the other species we share the planet with. Evidence of human interference with the natural world is visible in practically every ecosystem, from the presence of pollutants in the stratosphere to the artificially changed courses of the majority of river systems on the planet. It is argued that humans have continually manipulated their natural world to meet their needs ever since we abandoned nomadic, gatherer-hunter ways of life for settled societies some 12,000 years ago. While this observation is correct, the rate, scale, and the nature of human-induced global change — particularly in the post-industrial period — is unprecedented in the history of life on Earth.
There are three primary reasons for this:
Firstly, the mechanization of industry and agriculture in the last century resulted in vastly improved labor productivity, enabling the creation of goods and services. Since then, scientific advances and technological innovations — powered by ever-increasing inputs of fossil fuels and their derivatives — have revolutionized every industry and created many new ones. The subsequent development of Western consumer culture, and the satisfac