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We are currently immersed in the 6th mass extinction crisis in the history of our planet, and the most serious one yet. Each of the past five mass extinctions took place because of a major physical process, yet this is the first crisis to emerge from a single species- humans. Currently, forty percent of earth’s land is devoted to human food production. In order to cultivate this land, we first need to clear it, destroying the homes of many animals. In all, fifty percent of earth’s land mass has been transformed to benefit the human race. Land that used to be filled with diverse wildlife is now home to cities with almost no animals and even less vegetation. Besides habitat destruction, species are hurt by pollution, hunting, climate change, and invasion by alien species. Yet all these things lead back to a single cause- human population growth. As our population grows, we are burning more fossil fuels by driving more cars and manufacturing larger quantities of goods,introducing toxic chemicals to the environment that kill animals when ingested. We are hunting more, and not just for survival, but for sport. We are exploring new parts of the world, purposefully and accidentally introducing species to new parts of the globe where they often prove to be quite destructive. Worldwide, 12 percent of mammals, 12 percent of birds, 31 percent of reptiles, 30 percent of amphibians, and 37 percent of fish are threatened with extinction. These species are each important to the global environment and to humans in their own way, whether as a food source or a pollinator, or whatever other role they occupy. Without the world’s animal and plant diversity, the human race could not and will not be able to live like we do now, if at all.
Graph source: www.biologicaldiversity.org/programs/population_and_sustainability/extinction/index.html
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Malthus Theory of Population
In 1798, a economist named Thomas Malthus theorized that human population would exceed the food supply. He believed that while the population grew exponentially, food production grew in a linear fashion. Although that was proven to be wrong, there is much more of his theory to look at. Malthus believed that there could be many signs of reaching the carrying capacity. There were two ways he believed that human population growth could be controlled: “preventive checks” meaning that people could marry later in life to lower the amount of births in a family, or there would be “positive checks” on the population which he described as a shortening of human’s lifespan. Later, there were new additions added to preventive checks such as birth control. Malthus believed that if the human population started to exceed the carrying capacity the positive checks would start to occur. This meant there would be more disease, more poverty, and more war. Studies have been done in the last ten years showing that there have been an increasing amount of wars per year. With every war there is fallout, generally an increase in poverty and a shortage of food as well as a loss of life. As the population is still increasing, the numerous wars must not be having a very large impact on the overall population of the world. This could mean that the number of wars will continue to increase until the population is checked.
Sources:http://cgge.aag.org/PopulationandNaturalResources1e/CF_PopNatRes_Jan10/CF_PopNatRes_Jan108.html-Malthus theory and graph
https://www2.warwick.ac.uk/newsandevents/pressreleases/wars_steadily_increase-amount of wars have been increasing
In 1798, a economist named Thomas Malthus theorized that human population would exceed the food supply. He believed that while the population grew exponentially, food production grew in a linear fashion. Although that was proven to be wrong, there is much more of his theory to look at. Malthus believed that there could be many signs of reaching the carrying capacity. There were two ways he believed that human population growth could be controlled: “preventive checks” meaning that people could marry later in life to lower the amount of births in a family, or there would be “positive checks” on the population which he described as a shortening of human’s lifespan. Later, there were new additions added to preventive checks such as birth control. Malthus believed that if the human population started to exceed the carrying capacity the positive checks would start to occur. This meant there would be more disease, more poverty, and more war. Studies have been done in the last ten years showing that there have been an increasing amount of wars per year. With every war there is fallout, generally an increase in poverty and a shortage of food as well as a loss of life. As the population is still increasing, the numerous wars must not be having a very large impact on the overall population of the world. This could mean that the number of wars will continue to increase until the population is checked.
Sources:http://cgge.aag.org/PopulationandNaturalResources1e/CF_PopNatRes_Jan10/CF_PopNatRes_Jan108.html-Malthus theory and graph
https://www2.warwick.ac.uk/newsandevents/pressreleases/wars_steadily_increase-amount of wars have been increasing