What alternations in our course are necessary? Experts disagree, but many believe that the key to our long-term survival lies in the widely ignored lessons of nature.
Consider these facts: undisturbed ecosystems persist for decades, centuries, even millions of years.
The rate of extinction in such ecosystems is low. Human society, on the other hand, now wipes out a vertebrate species every nine months and itself faces global extinction after only a relatively short stay on earth.
Why is it that nature persists while we deplete and destroy? The secret of nature is that survival hinges on a sustainable system - a system that perpetuates itself without destroying the very things that permit life to continue.
Nature capitalizes on four major strategies to meet this end.
The first is recycling. The global ecosystem is a consummate recycler. Water, carbon, oxygen, nitrogen, and all other substances are used over and over.
The long-term future of humankind depends on following a similar direction.
Nature's second secret is the use of renewable resources - resources that renew themselves through natural biological or physical and chemical processes.
Wood, water and wind are examples. For millennia, humankind heated its homes with wood, reaped the riches of the biological world for food, and fashioned its goods from flax and other plant products. Only in the past 200 years has our allegiance to renewable resources wavered. Today, we depend heavily on a variety of nonrenewable substances: fuel, plastics and synthetic fabrics made from oil; metals and so on. Our new dependency, many think, is a dangerous trap. It cannot be sustained indefinitely. Our long-term future requires a greater dependency on resources in a form of self care.
Nature's third secret is conservation. An obese ostrich does not exist in nature. For the most part, organisms use what they need - no more, no less. Modern industrial societies, on the other hand, are often gluttonous, overeating, wastefully consuming and recklessly depleting. Ecologists warn us that we cannot do so forever with impunity.
The fourth secret of nature is population control. Through a variety of ways, populations of living things are kept from living beyond their means. Predators trim the prey populations. Diseases eliminate the weak and aged. Environmental conditions keep populations from exploding. For humans, technological advances, medicine and sanitation have removed many of the natural barriers for human population explosion. The upshot of the rapid human population expansion is often foul-smelling skies, filthy water and landscapes devoid of vegetation and animal life. The ecosystem is sacrificed to continue population growth. Most ecologists agree that we must learn to control our numbers to preserve the global ecosystem.
Such are the secrets of nature: recycling, renewable resources, conservation and population control. It is ironic that today we must go back to nature to relearn these forgotten lessons. If we are to survive for thousands of years to come, we must build a sustainable society, a society that lives in harmony with nature.
Not a society that seeks complete domination over all living things or destroys its renewable resource base. Building a sustainable society does not mean reverting to a primitive existence, it means using resources in a pattern laid down by nature.
Read the following text and then discuss the problem. Here are some ideas for' and 'against' plastic which are summarized in note form. Enlarge on them, contribute, if possible, ideas of your own.
When plastic was invented at the beginning of the 20thcentury, we could hardly have realized what a profound effect it would have on the future of the environment. The very virtues which make plastic so useful, namely strength and durability, are precisely what makes it such a problem.
What is plastic?
Plastic is derived from oil, comes in a multitude of shapes and forms, and is used for a vast array of purposes. Being strong, light and flexible it is a symbol of our disposable society.