Environmental Science Questions - Essay Example

Mars has 95 percent carbon dioxide, three percent nitrogen, two percent argon and less than one percent of oxygen. The differences and similarities offer clues of atmospheric evolutions over millions of years. In the same manner, if all life ceases on earth, it would take several hundreds of millions of years for it to be like Venus and Mars. Of all life forms, plants play the most significant role in reducing levels of carbon dioxide in Earth’s atmosphere. Without plants, the Earth’s atmosphere would be carbon-dominated in a similar way to Mars and Venus.

For instance, millions of years ago, Venus was cooler that it currently is. Via a process known as runaway greenhouse effect, the planet was heated and most of the carbon dioxide in the rocks was released. This created a dense atmosphere that did not allow enough solar energy to reach the surface as well as hindering radiation back into the space. Effectively, without life on Earth, especially plant life, the atmosphere would eventually have no oxygen and hydrogen and be laden with carbon dioxide.

Temperatures and atmospheric pressure would also rise significantly. Question Two The Gaia hypothesis suggests that on Earth, there is a constant interaction between organisms and their inorganic surroundings. Evolving together, they form a complex, self-regulating system which contributes to the maintenance of the conditions supporting life on earth. The hypothesis is a true representation of how nature works because it explains how the abiotic environment is influenced by the biota and how, in turn, the environment influences the biota.

For example, from the Precambrian era, photosynthetic bacteria and their activity have modified the atmosphere of planet Earth and transformed it into an aerobic one, which supports the evolution of life. This aspect of Gaia renders true the fact that the earth is constantly seeking the optimum chemical and physical balance to sustain contemporary life via an assortment of feedback loops. The hypothesis brings out the dynamic processes on earth and shows that there actually exists a link between the apparently contrasting biological and physical processes.

Indeed, the balance as explained by the hypothesis regulates the salinity of oceans, atmospheric oxygen, carbon dioxide processing and Earth’s surface temperature. Like shown through scientific examples like the simplified Daisyworld simulations, organisms on Earth can influence and control their own survival as well as the environment. In the simulations, black daisies absorb most of the solar energy, making the environment unbearably hot. On the other hand, white daisies reflect back most of the solar energy, making the environment significantly cooler.

When self-regulation takes over, there is a fluctuation in the number of black and white daisies and, eventually, the atmospheric temperature until a balance which can sustain life is achieved. Question Three In a natural environment, there exists a mixture of species with varied levels of success. One species or a combination of several may overshadow the rest in biological activity and their mass, hence become the dominant one. They greatly affect environmental conditions for other species.

Conversely, there are also other species of intermediate abundance or scarcity, and their numbers primarily determine the diversity (or the richness in species) of the community. When a