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Bell Work. What are 4 reasons why it is important to recycle?. Intro – Lecture 32 (Yesterday’s Lecture number should have been 31 not 34). Ecological Threats. Threats to species. Many different factors threaten the survival of species. These factors can lead to extinction.
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Bell Work • What are 4 reasons why it is important to recycle?
Intro – Lecture 32(Yesterday’s Lecture number should have been 31 not 34) Ecological Threats
Threats to species • Many different factors threaten the survival of species. • These factors can lead to extinction.
Most Extinctions are From Human Related Behaviors • Exploiting natural resources, such as the world's oceans, faster than they can be renewed • Draining wetlands and clearing forests and grasslands for agriculture and towns and cities • Ruining habitat by fragmenting it with roads and development • Over-harvesting trees to make building supplies and paper products and for use as fuel • Introducing harmful species into foreign ecosystems • Releasing toxic pollutants • Poaching, unsustainably hunting or illegally trading wildlife
Major Ecological Threats • Overfishing • Climate Change (Global Warming) • Poaching, Illegal Trading • Deforestation • Loss of Habitat (Over-Population) • Pollution
Overfishing • Overfishing occurs when more fish are caught than the population can replace through natural reproduction. • This wipes out a link in the food web.
Bicatch • The incidental capture of non-target species such as dolphins, marine turtles and seabirds. • Marine life of all types is hauled up with the catch, and then discarded overboard dead or dying.
Climate Change • This problem is partly due to carbon pollution. • Sea levels are rising and oceans are becoming warmer. • Longer, more intense droughts threaten crops, wildlife and freshwater supplies. • Thinning polar ice endangers polar bears • Tropical amphibian diseases threaten rainforest
Illegal Wildlife Trade • Unregulated hunting and trading, especially in biodiversity-rich countries, poses grave threats to both humans and animals.
Illegal Wildlife Trade • Run by dangerous international networks, wildlife and animal parts are trafficked much like illegal drugs and arms. • Examples: poaching of elephants for ivory, tigers for their skins and bones, marine turtles, and even timber trees.
Habitat Destruction • Destruction or ecosystems can cut off migration routes and access to resources, leading to decline of species populations or even extinction.
Deforestation • Many of the world’s most threatened and endangered animals live in forests. • Deforestation comes in many forms, including fires, clear-cutting for agriculture, ranching and development, unsustainable logging for timber, and degradation due to climate change.
Forests play a role in climate change because they trap all the carbon dioxide and other greenhouse gases that would be released into the atmosphere and turn it into oxygen.
Pollution • Pollution is the introduction of contaminants into the natural environment that cause adverse change
Pollution Examples • Streams full of toxic chemicals from industrial processes • Rivers overloaded with nutrients from farms • Trash blowing away from landfills • City skies covered in smog
Effects of Pollution • Pollution may muddy landscapes, poison soils and waterways, or kill plants and animals. • It can also cause and spread diseases.
Three Main Types of Pollution • Land Pollution • Air Pollution • Water Pollution
Sources of Land Pollution • Chemical and nuclear plants • Industrial factories • Oil refineries • Human sewage • Oil and antifreeze leaking from cars • Mining • Littering • Overcrowded landfills • Deforestation • Construction debris
Facts About Land Pollution • Every year one American produces over 3285 pounds of hazardous waste • Land pollution causes us to lose 24 billion tons of top soil every year • Americans generate 30 billion foam cups, 220 million tires and 1.8 billion disposable diapers every year • We throw away enough trash every day to fill 63,000 garbage trucks • Every day Americans throw away 1 million bushels of litter out their car window • Over 80% of items in landfills can be recycled, but they’re not
Sources of Air Pollution • Automobile emissions • Tobacco smoke • Combustion of coal • Acid rain • Noise pollution from cars and construction • Power plants • Manufacturing buildings • Large ships • Paint fumes • Aerosol sprays • Wildfires • Nuclear weapons
Facts About Air Pollution • Almost 232 million different types of vehicles are driven by U.S. citizens every day, adding greenhouse gases into the air • U.S. vehicle emissions contribute 45% to global warming • The average adult consumes 3,000 gallons of polluted air every day • Vehicle exhaust contributes to 60% of carbon monoxide emissions in the U.S. and up to 95% in large cities • Every year 335,000 Americans die of lung cancer, which is a direct result of air pollution
Sources of Water Pollution • Factories • Refineries • Waste treatment facilities • Mining • Pesticides, herbicides and fertilizers • Human sewage • Oil spills • Failing septic systems • Soap from washing your car • Oil and antifreeze leaking from cars • Household chemicals • Animal waste
Facts About Water Pollution • Over two-thirds of U.S. estuaries and bays are severely degraded because of nitrogen and phosphorous pollution • Every year almost 25% of U.S. beaches are closed at least once because of water pollution • Over 73 different kinds of pesticides have been found in the groundwater that we eventually use to drink • 1.2 trillion gallons of sewage, storm-water and industrial waste are discharged into U.S. waters every year • 40% of U.S. rivers are too polluted for aquatic life to survive • Americans use over 2.2 billion pounds of pesticides every year, which eventually washes into our rivers and lakes