SUSTAINABILITY

 INTRODUCTION

 All of the damage to and degradation of the biosphere and the environment are evidence of how destructively humankind now treats the planet. Global climate change, elimination of rain forests, loss of species, pollution of air and water, depletion of soils -- the list goes on and on. Everyone seems to agree that we are making a mess of things, and that we ought to change our ways. Sustainability is the catch-word for the new way of managing resources, in order to ensure a more secure future. However, figuring out exactly what we mean by sustainability, and then determining how to get from here to there, will engage many of our most able minds for a long time.

 Even defining the concept is not easy. Most writers emphasize the following ideas:

  1. continuance of the human species depends on the ability of the human species to use the world's natural resources in a sustainable way, without destroying the "capital".
  2. economic activity must account for the environmental costs of production.
  3. the entire human family must benefit from the planet's resources; if 4/5 of its people are poor, we cannot hope to maintain peace or protect the environment.

This last point is very important, and I believe it is transforming how we think about the relationships between conservation and sustainable development. Sustainability could be discussed separate from economic development and the improvement of human needs -- in other words, we could maintain the status quo of economic well-being, including the discrepency between rich and poor nations. However, it seems that virtually everyone agrees that the lot of the 4/5th of humankind living in malnutrition and poverty should be improved. Hence the linking of the sustainability concept with economic development leads to the term, "sustainable development".

SUSTAINABLE DEVELOPMENT -- VARIOUS VIEWS:

Sustainable development has emerged as the means by which biodiversity and natural ecosystems can be saved, while enabling humanity to prosper. Some quotes from some milestone documents include: 

 Something is largely missing here. What about species? What about ecosystems? The Brundtland report calls for the world’s economic growth to rise to a level five to ten times the present output and for accelerated growth in the developed countries to stimulate demand for the products of poor countries. This is conservation???

As concern for humanity -- social justice -- has been inserted into the debate, has conservation of species and ecosystems been pushed aside?

A better definition might be, "human activities guided by acceptance of the intrinsic value of the natural world, the role of the natural world in human well-being, and the need for humans to live on the income from nature’s capital rather than the capital itself" (Meffe and Carroll 1997). These authors argue that "sustainable growth" is a contradiction in terms. "Sustainable development" might be realistic -- that is the issue before us.

 Solutions likely include the following:

SUSTAINABLE HARVESTING OF A SINGLE SPECIES

The essence of sustainable use of a natural resource can be illustrated with a fish harvest. Consider a naturally-reproducing population of fish, which is harvested for food or commerce. How many should one harvest? Clearly, only the number that leaves enough remaining individuals to replenish the population, indefinitely. A simple mathematical model, based on the sigmoid growth curve, provides a rough answer. The answer in this model is the halfway point. It might help you to think of this as the intersection of two curves -- the expanding, concave up curve; and the point where limitations begin to put the brakes on growth.

However, when we shift our sights to global sustainability, we run into a number of very difficult problems, chiefly the inter-related, sheer complexity of it all. There is no single "thing" to manage sustainably -- instead, there is an incredibly long list of natural resource variables. I think the key is to always move in the direction of increased sustainability, and away from unsustainable practices. An illlustration: sustainable agriculture.

Sustainable Agriculture:  

new crops: Most of the world's nutrition is derived from a handfull of species of grains, fruits, and other plant and animal sources. A huge, unutilized storehouse of species and genetic varieties remain unexploited for food, materials, and medicines. The potential for developing new crops is impossible to reckon.

new methods: (and maybe some old methods)

small plot size -- disturbs less land, reduces erosion and nutrient loss

crop diversity -- planting a mixture of crops promotes soil fertility, and pest and disease control

crop succession -- crop rotation has similar effects as diversity; mixing cereal crops and legumes adds nitrogen to soil 

natural fertilizers -- use of manure and plant waste recycles nutrients and reduces groundwater pollution

pest resistance -- crop diversity and succession minimize pest build-ups; integrated pest management (IPM) uses bio-control and improved biological knowledge to minimize use of pesticides

weed resistance -- crop rotations and use of cover crops to minimize weed build-up

disease resistance -- genetically engineered strains can improve plant resistance to disease

tillage techniques -- methods of cultivation that do not disturb the top soil as deeply but aerate and loosen the soil

agroforestry -- planting trees and shrubs among crops can add nutrients, reduce erosion, retain water and produce harvestable crops such as fiber, fruit, nuts, fuelwood

precision agriculture -- use of computer, GPS, to plant, fertilize, and apply agro-chemicals precisely and to use as little as necessary.

In the future, science and technology -- genetic engineering, precision agriculture, and integrated pest management -- will help us produce more food on less land. If we can avoid some of the mistakes of the past, sustainable agriculture techniques can be an important component of building a sustainable society.

 

 

Web sites:

Sustainable agriculture: http://www.wri.org/wri/sustag/

Sustainable forests: http://iisd1.iisd.ca/wcfsd/default.htm