Finally, since human beings are uniquely capable of producing materials not found in nature, environmental degradation may be due to the resultant intrusion into an ecosystem of a substance wholly foreign to it.
Because the global ecosystem is a connected whole, in which nothing can be gained or lost and which is not subject to over-all improvement, anything extracted from it by human effort must be replaced. Payment of this price cannot be avoided; it can only be delayed. The present environmental crisis is a warning that we have delayed nearly too long.