Types of Harmful Human-Environment Impacts: Conclusion
I’m looking forward to the New Year. Yeah, I know it’s dangerous, especially for someone my age, to wish away the present, but I’m looking forward to dealing with and hopefully resolving some of the problems I have put before you during the past seven months.
In my first posts I aligned my goals with Dogwood’s mission: to contribute to a more equitable and sustainable human existence on planet Earth. In subsequent posts, I demonstrated how our present ways of living are neither equitable nor sustainable. Since the 1980s we have been living in global “ecological overshoot”: our demands on nature are exceeding the planet’s capacity to provide. We are impoverishing future generations from enjoying the same natural abundance that we have. I also demonstrated that responsibility for our ecological impact is very unevenly distributed: people living in low-income countries are primarily responsible for increasing population, while those in richer countries are consuming a vastly disproportionate share of the world’s resources.
In my last posts of the year, I concluded with presenting the four major kinds of harmful human impact on the environment. I have already examined habitat loss and pollution, and now discuss biotic changes and exploitation of wild living resources.
Biotic changes
When humans manipulate living organisms within their environment or introduce new ones, they are making biotic changes which can interfere with local ecosystems. Consider Scotch broom which a British officer introduced to the Pacific coast in the 19th century. It is destructive to existing ecosystems because “it grows rapidly, crowding out native plants and preventing regrowth, retarding or preventing the growth of many understorey species, preventing the regrowth of forests, leading to a dramatic loss of diversity. It forms dense thickets, shelters feral animals, reduces food for native wildlife, blocks paths and creeklines. Scotch broom also changes soil chemistry, making it unsuitable for local native plants.” (http://www.broombusters.org/broom.html)
A potentially far more dangerous set of biotic changes involves the genetic manipulation of existing species which can produce brand new life forms. CBC New reports for example, “the typical Canadian kitchen is likely to contain many ingredients or foods that have been genetically modified. Everything from bread to tomatoes, corn and soya oil has been produced from altered food organisms.”
Although humans have practiced selective breeding of plants and animals for thousands of years, genetic engineering takes this practice to a new level. Geneticist and environmentalist David Suzuki outlines the dilemma:
“As a science that goes to the very heart of all life’s forms and functions, genetics has enormous implications; it is full of promise to benefit and improve human lives, but equally heavy with potential to destroy and cause untold suffering. For those who care about the long-term flourishing of genetics, it is vital to raise questions and anticipate problems, as well as proclaiming the potential benefits” (From Naked Ape to Superspecies, 1999, p. 102).
Exploitation and extinction of wild living resources
The rationally efficient and growing human exploitation of the earth’s natural resources forms the basis for the scientific claim that the world is about to experience a mass extinction every bit as great as that which destroyed the dinosaurs 6.5 million years ago. Says world famous paleoanthropologist Richard Leakey,
“Whatever way you look at it, we’re destroying the Earth at a rate comparable with the impact of a giant asteroid slamming into the planet, or even a shower of vast heavenly bodies.”
Leakey is not alone. According to a survey of 400 research scientists, all members of the prestigious American Institute of Biological Sciences, 70% “believe that we are in the midst of a mass extinction of living things, and that this loss of species will pose a major threat to human existence in the … [21st] century.”
Both Leakey and the 400 scientists surveyed attribute the cause of this new major extinction almost entirely to the actions of humankind. Increasing population and the growing rate of consumption of natural resources are putting the biosphere under severe stress.
Habitat loss and fragmentation, pollution, and biotic changes to the environment are collateral contributors to the massive loss of biodiversity that is occurring. Although scientists do not know how much biodiversity is actually required to support human life as we know it, they are adamant in their conviction that it represents the key to our continuing survival.
As I noted at the outset, I look forward to discovering ways whereby we can resolve the ecological problems we have created, and I hope you will join me in this challenge. No one can do it alone: if we all have been part of the problem, then we all must join together in the solution.
Have a great holiday and I’ll see you in the New Year!