Why are resources being polluted?

Transcription

1 Why are resources being polluted?

2 In consideration resources, there are two parts to the equation: consumption and disposal of waste. Pollution is when more waste is added than a resource can accommodate There are three types of pollution: air pollution, water pollution, and land pollution.

3 Air pollution is a concentration of trace substances at a greater level than occurs in average air The three human activities that promote the most air pollution are the use of motor vehicles, industry, and power plants.

4 Global Warming on a global scale air pollution may be contributing to global warming The Ozone Hole it may also be damaging the ozone layer

5 A climatic warming effect caused by permitting incoming solar radiation but inhibiting outgoing terrestrial radiation. Three gases are the primary cause: Carbon Dioxide (CO 2 ) Methane (CH 4 ) Water Vapor (H 2 O) The anticipated increase in the earth s temperature caused by carbon dioxide trapping some of the radiation emitted by the surface is called the greenhouse effect

6 Fig : Annual mean temperatures have increased almost 1 C. since 1880.

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9 Human-induced rise in CO 2 levels is theorized to lead to unnatural warming of atmosphere. Likely effects: Increased storminess Rising sea level (.2-1 meter in 100 years IPCC, 2001) Loss of arable land (some areas hotter, others cooler) Extinction of thousands of species Loss of nearly all coral reef Possible effects even include climate flip-flop wherein dangerous rapid cooling sets in!

10 Fig : Tuvalu is a small Pacific island nation with about 10,000 people. It fears that rising sea levels could flood the island.

11 Humans could adapt to a warmer climate, but major global changes would result in massive migrations and accompanied political disputes.

12 The stratosphere (9 to 30 miles above earth s surface) contains a concentration of ozone gas Protective layer is threatened by pollutants called chlorofluorocarbons CFCs such as Freon (used as a coolant in refrigerators and air conditioners) when leaked are carried into the stratosphere and break down the protective layer

13 On a regional scale, air pollution may damage vegetation and water resources through acid deposition Sulfur oxides and nitrogen oxides are emitted into the atmosphere through the burning of fossil fuels. They enter the atmosphere where they combine with oxygen and water Tiny droplets form and return to the earth s surface as acid deposition/acid rain When dissolved in water the droplets may fall as acid precipitation US has reduced emissions significantly since 70s Geographers consider the problem that acid rain often falls in a different area than it s produced in

14 Fig : Due to prevailing winds, the highest sulfate deposit levels in North America lie east of the emission sources. Deposit levels in eastern Germany are higher than in the U.S.

15 Acid precipitation has killed many trees in the forests of the Czech Republic.

16 Severe where emissions are greatest, especially exhaust Has three basic components Carbon Monoxide improper burning produces this Hydrocarbans results form improper fuel combustion and evaporation of paint solvents. This combined with nitrogen oxides and sunlight from photochemical smog which caused respiratory problems, eye stinging and an ugly haze Smog depends on weather Progress is mixed

17 The same view as the previous slide, looking south from Paseo de la Reforma, on a clear day.

18 Mexico City has many vehicles and is located in a mountain basin that limits dispersion of air pollutants.

19 Pollution of water is becoming widespread because it is easy to dump wastes into rivers Water can dispose of much waste but volume often exceeds capacity of many rivers and lakes. 3t6ic diaba

20 Water-Using Industries Industries such as steel, chemicals, paper, and food are major water polluters. Require large amounts of water for processing and generate waste water; also accidents Municipal Sewage: sewers carry wastewater to be treated, but not all pollutants are removed; in LDCs sewers are not as common Agriculture fertilizers and pesticides are carried into water supply, expanded use may increase food supply but destroys aquatic life

21 Aquatic plants and animals consume oxygen but so does decomposing waste that we dump into water Biochemical Oxygen Demand (BOD) constitutes the oxygen consumed by decomposing organic waste. When it is high the water becomes oxygen starved and the fish die Also, warm water used for cooling changes composition of a lake or stream

22 Since the passage of US Clean Water Act and equivalent laws in other MDCs, most treatment plants meet high quality standards Thames was toxic until the 1960s when government tried to restore it to health Salmon caught in 1982 was first since 1833

23 Fig : The Aral Sea was the world s fourth largest lake in 1960

24 Fig : Large scale irrigation from the rivers feeding the Aral Sea led to its steady decline.

25 Fig : The Aral Sea in the former Soviet Union has shrunk dramatically in area and volume due to extensive diversion of water for irrigation.

26 Consuming a product leads to consumption of a byproduct About 4 pounds of solid waste is generated a day per person in US Paper products account for most Solid waste disposal The sanitary landfill is the most common strategy for waste disposal. More than ½ is trucked and buried in a landfill We disperse air and water pollutants but concentrate solid waste In the US, small city dumps have been replaced by larger regional ones. Some communities pay to use landfills in other states, like NY and NJ send to PA

27 Two other alternatives to disposing of waste have increased rapidly incineration and recycling Incineration burning trash reduces its bulk by ¾ and heat can be used as an energy source It does release toxins into the air and sometimes the ash is toxic

28 This large sanitary landfill is the destination for the solid waste of Cincinnati, Ohio and the surrounding area.

29 Fig : Paper products are the largest part of U.S. solid waste, followed by food and yard waste. Recycling can reduce solid waste considerably.

30 Hazardous waste includes heavy metals (mercury, cadmium and zinc), PCB oils from electrical equipment, cyanides, strong solvents, acids, and caustics. Must be placed into protective containers or they may leak and contaminate groundwater or air Breathing can cause cancer, birth defects, chronic ailments and even immediate death Burial was once believed to be enough Love Canal, NY: Hooker Chemicals and Plastic Co. buried toxic wastes in drums in 1930s and in 1953 school and houses built on dumpsite

31 As dump sites become hard to find and regulations are more strict, some companies are dumping in West Africa, sometimes through contracts, sometimes without official consent A Dutch cleanup team sprays water to liquefy polluted soil in Abidjan, Côte d'ivoire. Tons of poisonous chemical sludge were dumped at various sites around the port city in August, leading to at least ten deaths and renewed calls from environmentalists for tighter controls over international waste shipments. -National Geographic