Ecological Impact of Population Growth

Ecological Impact of Population Growth

Population Growth, the Environment, and Community Interactions:

In principle, the relationship between population size and the environment is very simple and equally direct. Living organisms consume natural resources to provide for their energy needs. The specific mechanism through which they accomplish this vary substantially: some organisms consume other living organisms; some consume only other organisms' waste products, or scavenge their left-over consumables; still others manufacture their energy by synthesizing energy from sunlight and elements occurring naturally in the gaseous atmosphere.

The unidirectional dependence of organisms that consume other organisms upon the continued availability of the latter is obvious, but what is less sometimes less apparent is the mutual interdependence of the continued health and viability of species who do not necessarily interact directly, such as where each interacts directly only with a third species or affects the state of other natural resources necessary for the survival of the first species (Castilla, 1999).

In the natural world, populations of predator species co-evolve with populations of prey species, with predation and the defenses it necessitates sometimes driving the evolution of traits beneficial to prey species in other respects as well. At the other spectrum of species interdependence are those unrelated except through coincidental circumstances, but whose parallel evolution links their continued viability to each other nevertheless. Consequently, significant changes in the population of one species often has the potential to affect other species, sometimes to the extent that population increases in one can, in only a few generations, completely wipe out one or more other indigenous species (Castilla, 1999).

Community interactions between and among species transcends the one- dimensional relationship between those who consume each other (or each other's wastes and byproducts). Certain species may rely heavily on non-consumable vital resources provided by another for securing suitable shelter, for one example; another species population may depend on the predation of its primary competitors by a third species, for another example (CWAC, 2007).

Human activity and population growth also plays a vital role in shaping ecological niches, and in many respects, to a degree that is completely out of proportion to the nature of non-human species, primarily because human technology often result in ecological changes occurring in the very short-term that far exceed the magnitude of ecological changes that normally take place only in the very long-term without human contribution.

The Effects of Human Activity on the Environment:

By virtue of our intelligence and technological achievements, human beings have the proven capability to alter global resources and other fundamental ecological elements of the biosphere far beyond the ability of any other species. Nevertheless, primarily because of the limits of scientific ethics on human experimentation, humans, as a species, have been omitted from many ecological studies, despite the obvious potential of human activity and population growth on the environment (Castilla, 1999).

Author Paul Ehrlich devised the famous equation for evaluating human impact on the environment as a function of three variables: (1) population, (2) affluence, and (3) technology (UWBR, 2004). Much more recently, William Rees, of the Fisheries

Center at the University of British Columbia introduced a method for quantifying the specific natural resource demand represented by each person, expressing the results as an ecological "footprint" (UWBR, 2004). Combined with the fact that by the turn of the 21st

Century, the global human population reached 6 billion, the implications for the future of the planetary ecological systems and biosphere are extremely ominous to say the least.

According to experts like Rees, developed countries like the United States and Canada already account for an extremely disproportionate (collective) ecological footprint, to the extent that the entire natural capacity of the Earth would already be exceeded by 20% were all its inhabitants consuming its resources at the rate of North Americans (UWBR, 2004). Furthermore, the mere rate of resource consumption represents only a relatively small part of the overall equation. Human industrial activity contributes to the depletion, destruction, erosion, and other dramatic changes to the ecological environment that are detrimental to nonhuman species whose continued health depends on ecological balance, as well as to future generations of human beings who will depend on its resources as well.