Latin America and the Environment

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Areas Where Humans Impact the Environment

•Water•Air and Climate• Landforms• Plats and Animals• Solid Waste Disposal

July 22, 2012

Water

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Water Avaliability•Much of Latin America has rich water resources•Mexico: •Lake Chapala•Largest body of freshwater•Lost 80% of its intake water since mid-70s •Most water is diverted for irrigation•Mexico City sank 9 meters during the 20th century due to ground water removal.•Rio Grande and Colorado River•Currently Mexico is in water debt due to lack of water in the Rio Grande•Problem due to dams, drought, and irrigation divergence•Creates tension between US and Mexico

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Regional Water Scarcity

July 22, 2012

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Water Quality

•Water pollution: when water is modified by one+ substances so that it cannot be used for a specific purpose (or that it is less suitable than before).• Large populationsincreased water pollution•Agriculture: Fertilizers, biocides, animal waste• Industry•Mining•Heap-leach gold mining (Peru) involves using large amounts of cyanide to extract gold, waste products are then dumped into rivers.•Mercury Mining (Brazil, Venezuela, and neighbors) involves using large amounts of mercury to extract gold, waste products are then leached into the Amazon

•Municipalities/Residences: detergents, landfills,sewage•Mexico City treats less than 10% of its waste water. Sewageriversfarmland for irrigation

• Leading cause of childhood deaths: diarrhea and water-related diseases (e.g. cholera and typhoid)

July 22, 2012

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Percentage of Population with Reasonable Access to Safe Drinking Water2004 Data

Reasonable access to safe drinking water is defined as the availability of at least 20 litres per person per day from an improved source within 1 kilometer of the user's dwelling.

July 22, 2012

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Percentage of Households in Major Cities Connected to Water and Sewers 2004 Data

90% of the developing world's wastewater is still discharged untreatedinto local rivers and streams.

July 22, 2012

Air and Climate

Sources of Air Pollution

• Transportation: 55%• Stationary fuel combustion (power plants, factors, etc.): 21%• Industrial Processes: 16%•Misc.: 6%• Solid Waste Disposal: 2%• 1.1 billion people live in urban areas with unhealthy air (this is worse now!)•Mexico City is particularly at risk• In Mexico City and Santiago, Chile pollution exceeds WHO heath standards 300 days/yr 1993 Data

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Types of Air Pollution

•Acid Rain• Photochemical Smog: nitrogen oxides+waterozone•More common in warm dry climates with low air circulation (aka Mexico City)•Primary sources: motor vehicles and industries•Damage lungs; increase asthma, bronchitis, pneumonia, and emphysema; damages vegetation

•Ozone Depletion

July 22, 2012

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Deaths Attributable to Urban Air Pollution2004 Data

World Health Organization

July 22, 2012

Landforms

How Humans Affect the Land• Excavation: canals, reservoirs, mines•Open-pit mining: iron, copper, sand, gravel, and stone•Surface mining: removes vegetation, topsoil, and rocks

• Dumping• Surface Depressions•Guatemala City•Mexico City•Contributed to earthquake damage

• Urban areas suffer much more impact than rural: much of Latin America is almost pristine, parts are almost fully transformed• Implications on plants and animals?

Plants and Animals

How do humans affect organisms?

• Latin America is home to major biodiversity hot spots•Lots of unique species and under high risk of disruption•100’s of plants and animals go extinct each year!

•Causes of organism extinction•Habitat destruction/changes: farming, logging, mining, municipality development•Consumption: unsustainable hunting, fishing•Aggravated by modern technology•Exotic species: shipping, traveling, purposeful introduction• Invasive species leave their natural predators and now have an advantage over local species•Diseases•Contamination: biocides, industrial and agricultural run-off•Biocidesdisease resistant strains, which disrupts natural food chain

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25 Biodiversity Hot SpotsAll of Central America and the Caribbean are identified as a biodiversity hot spot!

July 22, 2012

Status of soil degradation around the world1990 Data

Over the past 40 years, approximately 30% of the world's cropland has become unproductive

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Protecting Biodiversity• Laws•Convention on Biological Diversity (1992): 189 countries signed as of 2007•Convention on International Trade in Endangered Species (1973): 160 countries signed as of 2007•How do we get multiple countries to agree? Who has rights to animal/plant resources?

•Nongovernmental Organizations (NGOs)•Works with governments, people, and private companies to contribute to their effort•E.g. The Nature Conservancy: purchases critical habitats, Greenpeace: petition government officials to improve legislation, World Wildlife Fund

July 22, 2012

Solid-Waste Disposal

Why Waste?• Trash lasts a long time!•We study life in ancient Rome through their trash

•More people+more money=more trash• Types of waste•Municipal Waste: the stuff you put in your garbage cans•Second largest expenditure of most local governments in the U.S. (4.5 lbs/person/day)•According to WiseGeek, Mexico produces 30% more trash than the U.S.

•Hazardous Waste: material that may pose a substantial threat to human health or environment if improperly handled•Note: things like paint thinners, computers, bleach, used motor oil, weed killer technically aren’t hazardous waste

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Municipality Waste Disposal• Landfills: “Sanitary Landfills” waste deposited into trenches, compacted,

covered with soil, repeat.•Lack of standards•Produces leachate (rain+trash) which is usually toxic•Most are not large enough

• Recycling•Source reduction: produce less waste•Recycling: recover and reprocess used material•Limitations: 1) Expensive to collect recycling 2) Cost for products vary, 3) Less market for recycled goods• Pros: highly practiced in poor developing countries (e.g. Mexico City): individuals collect recycling and then sell it to middlemen, but highly dangerous to the individual

• Incineration: burning•Contributes to toxic air pollution and toxic ash•Can be okay, but needs lots of filtration/scrubber systems

•Can be used to generate electricity•Ash goes to landfillsJuly 22, 2012

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Hazardous Waste Disposal• Sources: chemical and oil industry•Usually dumped/buriedgroundwater issues•Other infrequently used methods: incineration, infrared heating, bacterial decomposition

•Radioactive Waste•E.g. Nuclear power plants, but companies that make things like plastics and smoke alarms generate radioactive waste too!•Much is put in landfills, significant sources (power plants) are usually stored in pools or in sealed containers and sunk or buried•Hanford, Washington…and it’s leaking…•Many foreign companies dump in the ocean

July 22, 2012