HS415 Environmental Health Unit 6 Greenhouse Gases, etc Greenhouse Gases Carbon Dioxide 35% increase since industrial age Combustion of Fossil Fuels Deforestation Methane 154% increase since industrial age Animal (cattle and sheep) gas Nitrous Oxide Water Vapor Climate Change Controversy Nobody argues that the earth is getting warmer and that climate change is occurring. Controversy is global warming part of the natural planetary cycle or does man have influence? Other issue is whether curbing CO2 emissions now will have a real impact in the immediate future. Kyoto Protocol: UN Agreement Protocol signed by 167 countries: US and Australia notable exceptions China and India have signed on Cut greenhouse gas emissions by 5% less than 1990 emissions. If unable can purchase carbon credits but are penalized in the future. Treaty expires 2013 Unintended Consequences of Climate Change Overpopulation: Feed Me!!! Pollution Improper Waste Disposal Depletion of Natural Resources Overcrowding/ Slums: Mixing of Human and Animal populations Increased Consumption What’s the cause? • Power plants, cattle, and cars are some of the major contributors of greenhouse gases such as carbon dioxide and methane. For decades human factories and cars have spewed billions of tons of soot and greenhouse gases into the atmosphere, and the climate has begun to show some signs of warming. We produce millions of pounds of methane by allowing our trash to decompose in landfills and by breeding large herds of methane-belching cattle. Nitrogenbased fertilizers, which we use on nearly all our crops, release unnatural amounts of nitrogen oxide into the atmosphere. What’s the cause? (cont.) Once these carbon-based greenhouse gases get into the atmosphere, they stay there for decades or longer. According to the Intergovernmental Panel on Climate Change (IPCC), since the industrial revolution, carbon dioxide levels have increased 31 percent and methane levels have increased 151 percent. Paleoclimate readings taken from ice cores and fossil records show that these gases, two of the most abundant greenhouse gases, are at their highest levels in the past 420,000 years. Overpopulation Scientists estimate that around 10,000 years ago, only about 5 million people inhabited the earth. By C.E. 1650, there were perhaps 500 million, and by 1800, 1 billion. Between 10,000 years ago and C.E. 1650 population size doubled 71 times. Overpopulation Dates and associated population estimates up to the present are as follows: mid-1800s, 1 billion 1930s, 2 billion mid-1960s, 3 billion mid-1980s, 4 billion present, 6.5 billion + Overpopulation • Human Population Growth – Rate of growth increased due to better: • agriculture, sanitation, medicine, energy sources • Overpopulation – Started few centuries ago – Is a global problem • Population Grows Exponentially Effect of Population on Earth Resources Degradation of the environment by pollution Pollution: Unfavorable alteration of our surroundings, wholly or largely as a by-product of human action Serious shortages of resources (including food) Is brought by straining Earth’s ability to provide food, clothing, shelter, and energy e.g., on the average, each of us, on a yearly basis, uses: 500 kg of steel, 25 kg of Al, 200 kg of salt Human Influences … • Our daily activities are having measurable effects on: – Rainfall – Climate – Air – Water quality – Erosion – Mineral resources • In North America, we use 20 tons of mineral resources per person/year Deforestation • Deforestation contributes to global warming, since we’re reducing the number of trees available to absorb carbon dioxide. • In the tropics, trees are burned as land is cleared, a practice that releases yet more carbon dioxide. • An estimated 20% of all carbon dioxide emissions are accounted for by the burning of the Amazon rain forest alone. System Approach • The whole Earth behaves like an organism • It is a self-regulating network of interdependent physical and biological systems • A disturbance (e.g., deforestation) in one part of the system (Earth) must result in adjustment in other parts (e.g., global warming) Quick Quiz The problem that is linked to all other life forms and is therefore the most important problem facing human beings is a) b) c) d) population increase. competition for resources. polluted air. loss of biodiversity. Tag…..your it. So what are YOU and your family going to do? Getting involved does not mean having to give up the comforts we work so hard to get and provide. Call or email your Congressperson and Senators on both the Federal and State levels. Meet your local Water Authority, City Council, Public Health Dept….etc.