Global Systems
Vitousek, et al. Issues
Vitousek says the major sources of land transformation are pastureland, agriculture, and urban industrial activity. Agriculture (fisheries, artificial environments, row-crops) are high on the list of land transformation, urban industrial activity medium, and pure pastureland low, depending on human involvement.
Humans alter the oceans in many ways, although some are not easy to quantify. Population centers are concentrated near coastal areas and coastal wetlands are also altered. Fishing alters the ecology of the oceans by focusing on the top predators and throwing the system out of balance. Pollutants and other man-made activities cause algal blooms that are toxic to the ecology of the oceans as well. It is the relationship between the different parts of the food chain that are most effected by human involvement.
Part 3 -- The earth can be viewed as a system concept, with the forests the lungs, the waters the veins, etc. This is balanced in nature, but human intervention causes C02 and other gases to be released into the atmosphere through fossil fuels, industry and other mechanized activities. The
Human activity has also altered the global Nitrogen cycle by deliberately fixing it to fertilizer and fossil fuel combustion. The consequences are many;
climate, flora, fauna, and eco systems all become out of balance; species become extinct, weather patterns change, thus changing human culture.
Part 4 -- Humans have a robust and profound effect upon the biotic systems of earth. Rates of
extinction are 100-1000X more than prior to human dominance; species loss then disrupts the ecology of the planet. Humans have also caused a rearrangement of the biotic system by transporting species into parts of the world they are not native (often meaning no predators) and thus destructive to the
environment. Humans change the composition of the atmosphere; buildings and freeways increase solar radiation, pollutants, etc. mar the earth's ability to recover quickly (Vitousek, P., et al.).
Foley, et al.,…
