Human Impact
Climate ChangeClimate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions, or in the distribution of weather around the average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions. Certain human activities have also been identified as significant causes of recent climate change, often referred to as "global warming".
During the past century, the temperature has risen by almost 1°C (about 1.3°F). That may not seem like much. But consider that just 10°C is the difference between an ice-free and an ice-covered Earth. Effects of Climate Change How has global warming affected Earth and its life? Some of its effects include:
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Just a few degrees
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Ozone DepletionOzone is trioxygen, or O3 and makes up a layer of the atmosphere responsible for blocking out UV radiation.
CFC's (chlorofluorocarbons) break down O3 and create holes in the ozone. CFC's were found in aerosol cans prior to 1979 and CFC-12 (freon) was used in refrigeration and car air-conditioning before 1995. Increased UV radiation reaching earths surface is a problem because it is a mutagen and can cause skin cancer and other health problems. Since the ban on CFC's much of the ozone depletion issue has subsided and the ozone has even began to repair. (O2 gas in the presence of UV radiation can produce ozone) 
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The picture above is of a life long truck driver. As you can see the side of his face that was exposed to sunlight on the drivers side of the car shows much more wrinkling and damage.
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Acid precipitationIndustrial pollution containing Nitrogen and Sulfur combines with water in the upper atmosphere creating Sulfuric (H2SO4) and Nitric Acid (HNO3). these two compounds are very strong acids and will lower the pH of the precipitation, creating acid rain. Acid rain is not especially acidic alone, but this slowly lowers the pH of the ponds and soil where it lands over time.
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pollution
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Nitrate can get into water directly as the result of runoff of fertilizers containing nitrate. Some nitrate enters water from the atmosphere, which carries nitrogen-containing compounds derived from automobiles and other sources. Nitrate can also be formed in water bodies through the oxidation of other, more reduced forms of nitrogen, including nitrite, ammonia, and organic nitrogen compounds such as amino acids. Ammonia and organic nitrogen can enter water through sewage effluent and runoff from land where manure has been applied or stored.
Nitrate (NO3) is a common inorganic form of nitrogen. Chemically, it is an anion with a single negative charge, consisting of one atom of nitrogen and three atoms of oxygen. Because it is an anion, it is soluble in water. Plants normally use nitrate as their source of the nitrogen needed by all living things, and so nitrate is considered a nutrient for plants. Excessive concentrations of nitrate in lakes and streams greater than about 5 milligrams per liter (measured as nitrogen), depending on the water body, can cause excessive growth of algae and other plants, leading to accelerated eutrophication or "aging" of lakes, and occasional loss of dissolved oxygen. Animals and humans cannot use inorganic forms of nitrogen, so nitrate is not a nutrient for us. If nitrate-nitrogen exceeds 10 milligrams per liter in drinking water, it can cause a condition called methemoglobinemia or "blue baby syndrome" in infants. Some recent studies have indicated a possible connection between elevated nitrate concentrations and cancer. Biomagnificationaccumulation of toxins like mercury, lead, or even DDT in organisms across trophic levels. These substances may be in low concentrations in the lower levels, but as we move up the food chain the concentration increases.
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Loss of Biodiversity
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Shows the effect of re-introducting wolves into an ecosystem- start at 29 minutes
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- habitat destruction
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Loss of biodiversity due to "slash and burn" farming and habitat destruction. Clear-cutting of forests is done to create farmland and the trees are also used for building and to make paper goods.
biodiversity is key to ecosystem stability, |
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- Overfishing
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Overfishing is a form of overexploitation in which fish stocks are depleted to unacceptable levels, regardless of water body size. Resource depletion, low biological growth rates, and critically low biomass levels result from overfishing. For example, overfishing of sharks has led to the upset of entire marine ecosystems.
The bluefin tuna, which has been endangered for several years and has the misfortune to be prized by Japanese sushi lovers, has suffered a catastrophic decline in stocks in the Northern Pacific Ocean, of more than 96%, in 2013. Equally concerning is the fact that about 90% of specimens currently fished are young fish that have not yet reproduced. |
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Exotic Species
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An introduced, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental. Non-native species can have various effects on the local ecosystem. Introduced species that have a negative effect on a local ecosystem are also known as invasive species. Not all non-native species are considered invasive. Some have no negative effect and can, in fact, be beneficial as an alternative to pesticides in agriculture for example. In some instances the potential for being beneficial or detrimental in the long run remains unknown.
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Fracking
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Conservation
Alternative Energy sources
Solar Energy |
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Wind Energy |
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Hydro Electric |
Geothermal |
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BioDiesel |
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Biogas DigesterSometimes called a "biodigester" or a "methane digester" these simple constructs produce natural gas in the form of methane from manure.
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