The cause of global warmingslides


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  • Carbon dioxide in the atmosphere plays a key role in making our planet liveable. It allows sun light to pass through the atmosphere and warm the earth. It also traps or absorbs some of the heat which radiates from the earth back into space. The warming effect caused by carbon dioxide absorbing the radiant heat from the earth causes water vapor to evaporate from the earth. The water vapor in the atmosphere absorbs even more radiant heat than the carbon dioxide which helps make our planet liveable. This thin layer of atmosphere thus acts as a “blanket” to make the planet earth liveable
  • The Greenhouse Effect and Global Warming Greenhouse Analogy: Anyone who has visited a greenhouse for growing plants or sat in a parked car with the windows closed on a warm summer day has experienced the principle behind global warming. The sunlight goes through the glass and the heat is trapped inside. The gases in the atmosphere surrounding the earth act much the same way. Incoming solar radiation passes through the atmosphere to the earth’s surface, but most of the outgoing radiation emitted from the surface of the Earth is absorbed by the greenhouse gas molecules in the atmosphere and reradiated back towards the earth. In other words, the greenhouse gases trap heat as it is reradiated from the earth back to space. The effect of this is to warm the earth's surface. Water vapor and carbon dioxide are the 2 most abundant natural greenhouse gases. This natural greenhouse effect keeps the earth about 60°F warmer than it otherwise would be. Without the greenhouse effect, life as we know it would not be possible.
  • CO 2 Concentration and Temperature Change - Next 100 Years Second, if the world proceeds on what's called a "business-as-usual" path; in other words, nothing is done to slow greenhouse gas emissions and they continue to grow at their present rate of about 1% per year, atmospheric CO 2 concentrations will likely be more than 700 ppm by the year 2100, and they will still be rising. This is nearly double the current level and much more than double the pre-industrial level of 280 ppm. State-of-the-art global climate models, computer models used by scientists to study the effects of global warming, project that anthropogenic emissions driving this CO 2 rise will result in a significant increase in global average temperatures over the next 100 years, an increase ranging from 2.5 °and 10.4 ° F (1.4 - 5.8°C).
  • The cause of global warmingslides

    1. 1. What causes globalwarming? You do,silly! Kevin Cummins Sierra Club Volunteer 1
    2. 2. Increases in carbon dioxide cause the earth to get warmerGreenhouse gases such as carbon dioxide (CO2) (plus other gases like methane) in the atmosphere absorb heat radiating from the earth.This trapped heat increases the evaporation of water from the oceans into the air to cause a greater increase in warming of the atmosphere. CO2 has a forcing effect on climate.The combined effect of water vapor, carbon dioxide and methane controls the temperature of the earth. 2
    3. 3. 3Source: OSTP
    4. 4. Carbon dioxide levels in the atmosphere are increasingCarbon dioxide is produced from burningwood, coal, gas, etc.The amount in the atmosphere has risenfrom 280 ppm (100+ years ago) to 370ppm today.This increase in carbon dioxide is theatmosphere is increasing the heat beingabsorbed from the earth. 4
    5. 5. 5
    6. 6. CO2,CH4 and estimatedglobal temperature(Antarctic ΔT/2in ice core era)0 = 1880-1899 mean.Source: Hansen, Clim.Change, 68, 269, 2005. 6
    7. 7. Today’s atmosphere blanket is too thick!The increase in CO2 in the atmospheretraps more heat and causes more watervapor to evaporate into the atmosphere.Our new blanket around the world issimply making the earth too warm!We need a thinner blanket for our earth! 7
    8. 8. What can happen if we don’t produce less CO2 ?Temperatures will get warmer.Glaciers will melt, ice sheets in Artic willmelt (Polar Bears hunt on ice sheets)Sea levels will rise. Utah will be on PacificCoast…. NOT!More droughts in dry areas and more rainand snow in wet areas.More violent weather around the world. 8
    9. 9. 2100 If nothing is done to slow greenhouse gas emissions. . . • CO2 concentrations will likely be more than 700 ppm by 2100 • Global average temperatures projected to increase between 2.5 - 10.4°F 9 Source: OSTP
    10. 10. 10
    11. 11. Surface Melt on GreenlandMelt descendinginto a moulin,a vertical shaftcarrying waterto ice sheet base.Source: Roger Braithwaite,University of Manchester (UK) 11
    12. 12. How can we stop the earth’s“blanket” from getting us to warm?We must start putting less carbon dioxide intothe air.Most the CO2 in the air will be around for 100years.We need to burn less gasoline in our cars.Burn less coal (or burn it cleaner) for ourelectricity.Use less gas to heat our homes.Use less gas and electricity in our factories andon our farms. 12
    13. 13. What can we use for energy to replace carbon based fuels?SolarBiofuelsWindNuclear Power (may be necessarywhether we like it or not!)Geothermal 13
    14. 14. We can also use less fuelHigher mileage carsLive and work closer to homeWalk, ride bikesBetter insulated homesUse more efficient lights (fluorescent/LED)More efficient factories 14
    15. 15. 15
    16. 16. What can you do about?Discuss it with your parents, friends andrelativesConserve more yourself.Write your elected officialsGo to college and find new and bettersolutions for the future. 16
    17. 17. So what’s the bad news/good news if we don’t act soon? Bad news: We could lose control of the temperature rise of the earth. CO2 and methane from warm tundra and oceans could be released to atmosphere. This could be beyond our control. A “run away condition” Good news: Schools would close. NOT! Good news: Maybe global engineering could save us! (reflectors in space, dust in space) 17
    18. 18. What can the future hold for you children?More community spirit- we all must worktogether to solve the global warmingproblemA safer world with fewer enemies. GWcan only be solved with world cooperation.Less proverty in the world. Solving theworld’s GW problem cooperatively willrequire that proverty be reduced. 18
    19. 19. As my high school teacher used to say:“Don’t be a carbuncle on the butt ofsociety!”Get out there and make the world a betterplace to live!And also don’t forget to take care of theelderly along the way (Myself included) 19
    20. 20. ReferencesIntergovernmental Panel on Climate Change,“The New”, A Special Report on Climate Change,“Defusing the Global Warming Time Bomb” by James Hansen,Scientific American, 290, no. 3, March 2004, pp. 68-77. (availablefor download at global warming Website: “Climate Change and Utah”, USEPA, EPA 236-F-98-007z. Sept.1998, available at : young children (story book style): 20
    21. 21. DisclaimerThe preceding is my opinion and does notnecessarily reflect the opinion of the SierraClub. 21