Unit 10 Environmental Impact

Unit Outline Population Carrying Capacity Resource Distribution Pollution Global Warming Recycling (Going Green) Conservation Energy NonRenewable Renewable Conservation Technology Solutions Short Term Long Term Issues: economic, quality, personal decisions, risk vs. benefit

Basics of Population Causes of growth: Agriculture and Technology Agriculture: Humans became the first and only species ever to control our own food supply, and steady population growth was the result. In the absence of other limiting factors, any population will expand to the limit of its food supply Technology: improved farming, division of labor, the industrial revolution, development of science, mathematics, improved healthcare and transport of goods all caused by the 1800’s a doubling of the population The History of Human Population Growth Years Human Elapsed Year Population 3,000,000 10,000 B.C. (Agricultural Revolution) 5-10 Million 10,000 1 A.D. 170 Million 1, (Industrial Revolution) 1 Billion Billion Billion Billion Billion Billion Billion

Growth Rates Worldwide Current rate of growth: 77 million per year, this adds up to the entire population of New York City, each month! A Germany each year, and a Europe each decade! US grows by 2.8 million each year alone! We are the fastest growing developed country! With the 3 rd largest population WORLDWIDE. Only China and India are more populated. In the US 11% of births each year is from teenage mothers* The world birth rate is 2.5 times more than the death rate (birth rate is how many babies are born, death rate is how many people die per year)

Carrying Capacity (K) K is the number of species that a given area can support without hurting its ability to continue supporting the population. It is not just having enough land for people to stand on, you must have food, water, energy, produce oxygen, produce goods, and accommodate waste. For all the people living in cities, there must be open spaces to provide necessities for life.

Overpopulation An area is overpopulated when: its long-term ability to support life (K) is being ruined. Overpopulation does not mean crowded. But the environment is strained to support the current population and will likely be unable to support a larger population.

Population Curve

Resources A resource is: a necessity to maintain life, grow, develop and reproduce. A natural resource is: a resource that the earth provides. Ex: air, water, land, food, nutrients, minerals, soil Someone living in a developed country uses 2x as much grain, 3x as much meat, 9x as much paper, and 11x as much gasoline as someone in a developing country. In the last 200 years, the US has lost 71% of topsoil, 50% of wetlands, 90% of mature forests, and 99% of tall grass prairie and over 8,000 square miles of land is lost to urban sprawl every year!

Environmental Limits- limit population growth Density Independent Factor: Affect all populations, regardless of their size. Ex: flood, drought, hurricane, tornado Density Dependent Factor: increasingly affect populations as population size increases (impacts larger populations more). Ex: disease, lack of food, lack of water, parasites

Pollution Point or Non-Point sources affect land, air, and water. Air Pollution: in 2004, the US was responsible for 22% of the worlds CO2 emissions, more than any other country alone, including China, which has 4x more people. China produces only 4.4%. CO2 is the primary gas responsible for 60% of global warming caused by greenhouse gasses. Green house gasses are natural and under normal conditions good and essential to keeping our planet warm enough to live on. When the amount of gasses increase, the planet becomes warmer. (Scientists aren’t sure if all the global warming we measure now is caused by just humans, or is partly human and partly natural. )

Global Warming More accurately called: Global Climate Change. Scientists have measured an exponential increase in CO2 levels over time associated with an increase in average global temperatures. A theory states that if the ice caps continue to melt due to warming, a major ocean current will stop. The current moves from Australia, up along Africa’s west coast, bringing warm water up past western Europe, to the North Pole, then down, bringing cold water along the east coast of America and south towards South America. If the current stops, warm water will not be brought up to Europe and cold water will not be brought to America. It could cause an Ice Age in Europe and extreme droughts to America. It would cause Global Climate Change and all weather patterns would also change.

Pollution Water pollution: In the US 40% of streams, 45% of lakes, and 50% of estuaries are unfit for fishing or swimming (the City of Greensboro gets its drinking water for residents from 4 area lakes) Almost 45% of our drinking water comes from groundwater and 38 states reported finding pesticides, pharmaceutical residue, hormones, and carcinogens (cancer causing agents) in their groundwater. Agriculture uses over 40% of our local water supply, and agricultural chemicals, eroded sediment, and animal waste have contaminated over 173,000 miles of waterways.

Agriculture Land use: In US: 45.4 % of land for pasture/crops Water use: In US, 40% of water to crops Pollution: 60% of water pollution from agriculture point and non-point, release over 400 noxious gasses, including 26% of US methane release and 68% of NOX, 90% of worlds agricultural land affected by soil erosion due to poor farming practices Nutrition: undernourished: not enough calories or nutrients, malnourished, enough calories but not proper nutrients, over nourished: excessive calories (may still not be getting proper nutrients)

Pollution: Waste Land Pollution: most waste in NC is put into landfills. Due to runoff and leaching into soils, waste can reach waterways or soils and cause land pollution. By the time a baby born today reaches 82 years old, he/she will have produced at least 60 tons of garbage. The average American creates 4.4lbs of solid waste every day. Average people in France only 2.9lbs, South Africa 1.5lbs, and Egypt and Pakistan less than 1lb per day. Rapid population growth increases the amount of waste that is put into landfills. Consumption of goods also creates waste. They are both equal parts of the waste problem.