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12. GEOLOGY & LOBAL CLIMATE CHANGE

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Presentation on theme: "12. GEOLOGY & LOBAL CLIMATE CHANGE"— Presentation transcript:

1 12. GEOLOGY & LOBAL CLIMATE CHANGE
THE NATURAL ENVIRONMENT: all living and non-living things that occur naturally on Earth POLLUTION: Chemicals added to the atmosphere, soil or water by natural events or human activities in high enough concentrations to be harmful to humans and other organisms

2 Mining affects water resources
Most mining activities are water-intensive and also lead to wastage of water [e.g. hydraulic mining] water is diverted through a system of canals to high holding tanks, then directed in jets to wash away entire hillsides.

3 As miners dig deeper into the ground to obtain the ore, they hit the water table and must pump out the water to keep the pit dry on the other end, groundwater level drops by several hundred to thousand feet and leads to drying up of many wells Copper Butte, Montana No Fish or plants

4 Cyanide is used to leach out gold from rocks
CYANIDE CONTAMINATION Cyanide is used to leach out gold from rocks Cyanide in the process leaks into the water and streams and kills fish, birds, and plants even at very small concentrations Massive quantities of this deadly poison, more than 2 million pounds annually, are used in the US. Gold mine with cyanide leach piles and ponds, Black Hills, S Dakota

5 MERCURY CONTAMINATION
Mercury has been used for centuries as a cheap and easy method to extract gold. It can extract as much as 60% of the gold. Like cyanide, it is a deadly toxin. Mercury introduced into the lakes and rivers of California during the 1849 Gold Rush, estimated to be 7,600 tons, is responsible even today for 50% of exposure in the San Francisco Bay area. Eating fish from lakes and rivers in the Sierra Nevada Range is not recommended. The Latest U.S. Center for Disease Control figures indicate that 8% of U.S. women of childbearing age have mercury levels so high that their developing babies are at risk of neurological damage.

6 Pollution due to mineral processing
Blast Furnace Smelting Process in which ore is melted at high temperature to separate impurities from the molten metal Dangerous gases such as CO2 and sulfur oxides are emitted during smelting

7 Pollution due to the Refining of Minerals
Huge quantities of waste are produced during the refining processes of most metals such as gold, iron, aluminum, uranium, ...

8 POLLUTION DUE TO FOSSIL FUELS
Fossil fuels impact the environment in each of the following stages: Production (Mining): Disturbance to land/water (habitat). e.g. BP Gulf Oil Spill, Summer 2010 Transport: Spills (E.g. Exxon Valdez, Alaskan Oil Spill, 1989) Combustion (Burning): Increases CO2 & other pollutants in the atmosphere

9 Environmental Pollution during Oil Production
Environmental pollution may happen accidentally during the production of oil and gas. Example: BP’s Gulf of Mexico accident at its offshore petroleum platform resulted in oil spill, the worst in US history. Pollution during production process

10 Hydraulic Fracturing (Fracking)
This method of extracting natural gas and oil is known to contaminate groundwater by drilling fluids, gas and oil. 2 min

11 Environmental Pollution During Transportation
Spills may occur while transporting the fossil fuels and cause environmental pollution. Exxon Valdez hit a reef and spilled 260,000 barrels of crude oil Led to Oil Pollution Act of 1990

12 Environmental Pollution During Combustion (burning)
Burning Coal Chemical components of coal: C, Hg, N, S Burning coal releases CO2, Sulfur oxides, Nitrogen oxides, Mercury, and Soot. Burning coal causes a more severe air pollution than burning either oil or natural gas, because coal burning releases more pollutants per unit of heat produced

13 Environmental Pollution During Combustion (burning)
Burning Oil and Gas Chemical components of oil/gas: H, C, N, S Burning oil/gas releases CO2, Sulfur oxides, Nitrogen oxides, & Soot

14 Environmental impacts of burning coal, oil & natural gas
Higher levels of CO2 results in: increase of global temperature (global warming) Melting of polar ice Sea level rise ( flooding of coastal areas). Sulfur oxides & Nitrogen oxides cause acid deposition Mercury released into the atmosphere readily moves to and accumulates in water and land where it harms humans and wildlife (applicable to coal only)

15 MINING LAWS General Mining Law of 1872 :
Established to encourage settlement in sparsely populated western states Allows companies or individuals (US citizens or foreigners) to stake mining claims on federal land Land purchased for $ an acre, valuable minerals extracted and all profits kept by owners.

16 Consequences of the General Mining Law of 1872
    Los Angeles Consequences of the General Mining Law of 1872 The Law contains no provisions for environmental protection >100,000 abandoned mines in USA; of these 50 are designated Superfund sites  US taxpayers are financing the cleanup of these sites: ravaged land, poisoned water, and lifeless ecosystems Chromium at the San Fernando Valley Superfund Site


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