Climate change is a growing concern as well, though it is somewhat debatable as to whether or not humans caused it. Natural changes in weather have had perhaps the greatest affect on biodiversity and ecological systems. The threat of humans shifting the climate is therefore extremely threatening to the natural environment. "Were the average temperature to rise by several degrees Celsius, that warming would probably be followed by potentially large reorganizations of some ecological communities." (1).

One last issue concerning the affects that humans have on biodiversity is that of overpopulation. Recent advances in science and medicine have allowed for much greater life span and a very small infant mortality rate. We are increasing in population more rapidly than ever before. The growing population causes displacement of natural environments, not only because we need more living space, but also because the demand for agriculture and industry becomes higher as a result.

It is painfully clear that in many ways humans have had a significantly negative affect on biodiversity and Earth\'s natural environment as a whole. It is essential to realize that as rational beings, humans have the ability to not only understand the problems we have created and what needs to be done to amend them, but also the capability of accomplishing these tasks. There are two basic venues of thought as to why we should protect biodiversity and our natural environment, one being intrinsic reasoning, and the other being anthropocentric.

Many believe that there are intrinsic reasons to protect biodiversity, separate from all human needs and desires. These arguments are based on the idea that humans are part of nature, not separate from it. Evolution, for example, is what allowed us to come into being originally, and humans are now destroying the same biodiversity that allowed evolution to happen. A similar, but slightly different principle behind the intrinsic theory, is that people did not create nature, and therefore should not have the right to destroy it. Every species has a right to not be eliminated by humans. Furthermore, because humans destroy natural habitats consciously, we should be responsible for fixing any unnecessary damage that we have done.

A somewhat contradictory view is the anthropocentric theory. This is based on the idea that biodiversity has value for us as humans. The first, most direct example of this lies in goods obtained from nature. The most important, and often overlooked, is food. It is natural and necessary for us to consume a variety of living things, from vegetables to animals, in order to remain healthy. Cloth is another such example; we need the diversity of life in order to make clothes for ourselves, whether they be cotton, as many are now, or animal skin, as used in the past. Other goods include pharmaceuticals and medicines that are derived from naturally existing sources. These have proven to be incredibly valuable to us, and millions of plants have never been chemically tested, which leaves many open opportunities for discovery of new organic remedies