Global warming


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  • In examining global warming, we will be looking at questions such as 
    Is the world getting warmer? 
    If so, are the actions of mankind to blame for earth’s temperature increases? 
    What can or should be done about global warming? 
    Are the potential resolutions to global warming worth the cost to implement them? 
  • This is a big picture examination of the earth’s climate 
    The Earth was formed around 4.6 billion years ago 
    And was originally very hot 
    However, the Sun’s energy output was only 70% of what it is presently 
    Liquid water was present on the surface around 4.3 billion years ago
  • The first life forms appeared ~3.8 billion years ago 
    Photosynthesis began 3.5-2.5 billion years ago, 
    which produced oxygen and removed carbon dioxide and methane, which are greenhouse gases, from the atmosphere 
    As a result, the Earth went through periods of cooling, commonly referred to as “Snowball Earth” and subsequent warming 
    Earth began its current cycles of glacial and interglacial periods around 3 million years ago 
  • The temperature of the earth is directly related to the energy input from the Sun.  Some of the Sun’s energy is reflected by clouds.  Other is reflected by ice. The remainder is absorbed by the earth. 
  •  If amount of solar energy absorbed by the earth is equal to the amount radiated back into space, the earth remains at a constant temperature. 
  •  However, if the amount of solar energy is greater than the amount radiated, then the earth heats up. 
  •  If the amount of solar energy is less than the amount radiated, then the earth cools down. 
  • Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980
  • To a certain degree, the earth acts like a greenhouse.  Energy from the Sun penetrates the glass of a greenhouse and warms the air and objects within the greenhouse. The same glass slows the heat from escaping, resulting in much higher temperatures within the greenhouse than outside it. 
  • Likewise, the earth’s atmospheric gases affect the ability of the earth to radiate the Sun’s energy back into space. 
    Nitrogen and  Oxygen  make up 99% of the earth’s atmospheric gases  and are non-greenhouse gases.  Water,  Carbon Dioxide,  and Methane  make up 1% of the earth’s atmosphere,  but are greenhouse gases, since they cause the earth to retain heat. 
  • Carbon dioxide stays in the atmosphere for approximately 100 years, methane lasts about 12 years. Other greenhouse gases last even longer.
    As these gases continue to raise surface temperatures, they trigger the release of even greater quantities of carbon dioxide and methane that are currently trapped in frozen Arctic permafrost and tundra soils, further increasing temperatures.
  • This spike is due to the exponential increase in the use of fossil fuels over the last 150 years. Shown here are emissions of carbon from  gas,  solid,  liquid fuels, and  the total carbon emissions. 
  • Malaria and cholera increase, due to temperature increase
    Shifting flora and fauna to different areas. Extinction of some species.
    More extreme climates in inland locations. More frequent and devastating hurricanes.
    Reduced snow cover in some areas. Glaciers melt in Antarctica.
    Reduction of areas suitable for human habitation, for example. lowland Bangladesh.
  • Future Carbon Emissions 
    will probably increase, especially in China and developing countries 
    This will result in a likely doubling of carbon dioxide levels within 150 years, due to 
    Increased coal usage 
    And increased natural gas usage, 
    although petroleum usage is likely to decrease due to increased cost and decreasing supply 
  • Global warming

    1. 1. Global Warming “The Greatest Threat” Presented By:- “Awanish Shukla”
    2. 2. Introduction Is the world getting warmer? If so, are the actions of mankind to blame for earth’s temperature increases? What can/should be done about these issues?
    3. 3. History of Earth’s Climate Earth formed ~4.6 billion years ago Originally very hot Sun’s energy output only 70% of present Liquid water present ~4.3 billion years
    4. 4. History of Earth’s Climate Life appeared ~3.8 billion years ago Photosynthesis began 3.5-2.5 billion years ago Produced oxygen and removed carbon dioxide and methane (greenhouse gases) Earth went through periods of cooling (“Snowball Earth”) and warming Earth began cycles of glacial and interglacial periods ~3 million years ago
    5. 5. Earth’s Temperature Solar Sun Energy Solar Energy
    6. 6. Earth’s Temperature Sun Solar Energy Radiation Cooling
    7. 7. Earth’s Temperature Sun Solar Energy Radiation Cooling
    8. 8. Earth’s Temperature Sun Solar Energy Radiation Cooling
    9. 9. What is Global Warming? •An increase in the earth's average atmospheric  temperature that causes corresponding changes in   climate and that may result from the greenhouse effect •Since the last century, Earth's mean surface temperature  increased by 0.8 °C.
    10. 10. Sun MAIN CAUSE Greenhouse Effect
    11. 11. Earth’s Atmospheric Gases Nitrogen (N2) Oxygen (O2) NonGreenhouse Gases 99% Water (H2O) Carbon Dioxide (CO2) Methane (CH4) Greenhouse Gases 1%
    12. 12. Households are Big Contributors to Climate Change Of all greenhouse gas emissions come from households: • Vehicles • Home Heating • Electricity
    13. 13. Our reliance on cars that burn fossil fuels is one of the major causes of increased levels of carbon dioxide in the atmosphere and it is the primary cause of urban smog.
    14. 14. Facts about Global Warming The world emits about 25.6 billion metric tons of greenhouse gases annually. These greenhouse gases last a long time. The amount of oxygen dissolved in the oceans may decline. Warming begets more warming.
    15. 15. Carbon (109 metric tons) 8 Worldwide Carbon Emissions 7 6 5 Total Liquid fuel Solid fuel Gas fuel 4 3 2 1 0 1750 1800 1850 1900 Year 1950 2000
    16. 16. Global Warming’s Impact on •HEALTH •VEGETATION • WEATHER •LANDSCAPE •POPULATION
    17. 17. Future Carbon Dioxide Levels  Increasing CO2 emissions, especially in China and developing countries  Likely to double within 150 years: Increased coal usage Increased natural gas usage Decreased petroleum usage (increased cost and decreasing supply)
    18. 18. So how can each of us slow global warming now?
    19. 19. Reduce our consumption of fossil fuels •Because greenhouse gas emissions are tied very closely to our energy consumption, using less fossil fuel based energy puts fewer greenhouse gases into the atmosphere. This will help slow global warming. •50% of electricity in the United States is produced from coal. (
    20. 20. We can make some simple substitutions •Replacing just 1 incandescent light bulb with 1 compact florescent bulb saves about 150 pounds of carbon dioxide per year! •If every household replaced just 5 high-use incandescent bulbs with compact florescent lights we'd collectively save more than $8 billion each year in energy costs and we would prevent the greenhouse gases equivalent to the emissions from nearly 10 million cars. Source:
    21. 21. Small changes really add up Drive JUST 10 fewer miles per week Annual savings: 520 pounds CO2 Replace your old refrigerator with a new Energy Star: Annual savings: 700 pounds CO2 Wash clothes in cold water only Annual savings: 500 pounds CO2 Reduce your garbage by 10% through greater recycling or reduced packaging Annual savings: 1200 pounds CO2 Caulk and weather-strip around doors and windows Annual savings: 650 pounds CO2 These are mid-range estimates from published sources; your savings may vary. *
    22. 22. Easy Solutions Turning off lights saves energy and money.  The more energy used, the more rivers are dammed or more fossil fuel is burned, causing air pollution and increased levels of carbon dioxide in the atmosphere.
    23. 23.  Making paper and plastic bags uses energy and resources.  The bags add to our litter and waste problems, and plastic is not biodegradable.  Recycling is not the best answer because collecting and recycling materials requires energy.  Instead, carry a reusable cloth bag or a knapsack with you.
    24. 24. Our take-home message… Each of us must take steps to protect our Earth's climate.