The largest human cause of dead zones is nutrient run off from abundant use of fertilizers, animal waste and sewage. The runoff is a bi-product of our agribusiness, farming practices and growing population. Before immense land development the wetlands acted as a natural barrier and filter. The runoff would be depleted in the soil by the plants before it could reach the rivers and ocean. Human commercial activity and land development have destroyed the natural shield of the wetlands.
For instance Carbon Dioxide from the atmosphere is synthesized by plants, which is ingested and metabolized by animals, which is converted to Carbon Dioxide during respiration and decay. Humans remove over 40% of the photosynthetic that effort plants in order to support human enterprises. When humans burn fossils fuels that increases the atmosphere Carbon Dioxide by 35%, then during the combustion stage the present of air (oxygen), Carbon Dioxide and water molecules are release into the atmosphere. Human has an impact on the Phosphorus Cycle as well as the Carbon Cycle. The Phosphorus Cycle is representative of the cycle of all biologically important mineral nutrients-those elements that have their origin in the rock and soil minerals of the Lithosphere, such as iron, calcium, and potassium.
As a result of man made activities such as the burning of fossil fuels and deforestation, the amounts of all of these gases in our atmosphere has greatly increased. Forests are extremely vital as they assist in naturally removing carbon dioxide and other polluting gases from the air. The concentration of carbon dioxide in our atmosphere has increased by over 30% within the past two centuries and levels of methane have doubled. In cities, many human activities have contributed to the amount of air pollution we have. There are two main sources of air pollution: anthropogenic sources (human activity) and natural sources.
Owing to the development of industry and the use of fossil fuels, the amount of carbon dioxide in the earth’s atmosphere has produced and the average global temperature seems to have risen. What’s more, deforestation can affect climate changes. The growing of trees and plants can absorb carbon dioxide from the atmosphere because of photosynthesis, however, deforestation lead to carbon dioxide emissions. Both of these can lead to global warming of the atmosphere. The report (UNEPWMO, 2004, P10) also pointed out, the burning of fossil fuels and deforestation are altering the composition of the atmosphere and contributing to climate change.
Some of which include, global warming, destruction of habitat, and soil erosion. Global Warming has gradually increased over the years and the destruction of the Amazon is one of the reasons why. Steve Schwartzman, director of tropical forest policy for the Environmental Defense Fund (EDF), discussed how much the Amazon actually plays a part in all of this. He states that, “About 15 percent of global greenhouse gas emissions come from tropical deforestation – more than from all the worlds’ cars, trucks, trains, ships and airplanes combined.” Rapid climate change is one of the biggest threats when dealing with the rainforest because so much of our Earths supply of greenhouse gases comes from it. The EDF is concerned that if more of the Amazon is cut down and global warming continues to be on the rise, the remaining rainforest will soon turn into a savanna.
“The increase in the mean temperature of the earth due to excessive emissions of greenhouse gases such as carbon dioxide, methane, and nitrogen.” ( Green) These extra gases are making it hard for heat to escape the Earth’s atmosphere resulting in warmer temperatures. Here is a model of the Greenhouse Effect retrieved from http://epa.gov/climatechange/kids/greenhouse.html. Ethical Issues on Global Warming There are many causes of Global Warming to include Carbon Dioxide from power plants, cars, airplanes, and from buildings. “In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation.”(Ayres) 93% of electricity generations is produced by coal. 33% of the carbon dioxide comes from vehicles.
People around the world highly depend on fossil fuels. Fossil fuels has powered the industrial revolution and helped to make the western world what it is today. But each year its becoming clearer that our uncontrollable use of fossil fuels is making us problems and will harm us in the far future. Fossil fuels have many uses that we depend on for instance if we don’t extract fossil fuels we won’t be able to use cars, airplanes, and trains. Moreover we use fossil fuels to power electricity plants and to heat our homes.
The production of these toxic-filled substances continues to lead the human race on a path of natural destruction; with thousands of animal sea-life dying annually from plastic consumption. It's time we wake up to the fact that our oceans are in need of critical help. How did the plastic get into our oceans to begin with? The oceans are enormous but they are not infinite. Today, as in the past, oceans are being treated as giant disposal areas for all types of refuse (plastics, tins, bottles etc.)
The United Nations Food and Agriculture Organization (FAO) “estimates that the annual rate of deforestation is about 1.3 million square km per decade, with the main deforestation occurring in the tropics where a wide variety of forest exist”. (“Deforestation”). Forest provide the planet with a wide variety of benefits, one being the absorption of carbon dioxide. Carbon dioxide is a greenhouse gas that in large amounts has a potential to alter the climate of the earth. With the depletion of the forest that converts the carbon dioxide into oxygen it has monumental negative effects on the planet as a whole.
Furthermore, mercury spreads and destroys plants and animals in the area. All of the above help to cause the greenhouse effect, affecting global warming massively. If this continues the oxygen throughout the world will decrease. A staggering 40% of the world’s oxygen supply comes from the rainforest. Statistics state, and I quote; “at this rate the rainforest only has 28 years left “.