Presentation on theme: "Greenhouse gases, global warming and the ozone layer"— Presentation transcript:
1 Greenhouse gases, global warming and the ozone layer ATMOSPHERE AND CLIMATEGreenhouse gases, global warming and the ozone layer
2 The Atmosphere Is a thin layer of gases that surrounds the earth Extends thousands of km above the surfaceThe reason there is life on Earth – we are protected from most of the sun’s radiationAllows some light to reach the surface, supplying energy and allowing photosynthesis (O2 and CO2)78% nitrogen, 21% oxygen, 1%= water vapor, argon, carbon dioxide, neon, helium, and other gases
3 HOW PHOTOSYNTHESIS CHANGED THE ATMOSPHERE The early atmosphere contained little oxygen.Bacteria appeared about 4 bya and evolved the ability to perform photosynthesis6CO2 + 6H2O + sun energy → C6H12O6 + 6O2
5 Troposphere 75–80% of the earth’s air mass Closest to the earth's surface0-11 km above sea levelChemical composition of airNitrogen 78%Oxygen 21%H20, CO2, trace amounts of others (Ar)Weather, climate and all life forms exist hereAs altitude increases, temperature decreases
6 Stratosphere 11-50 km (6-30 miles) above Earth's surface Similar composition to the troposphere, with 2 exceptionsMuch less water (1/1000)O3, ozone layerAs altitude increases, temperature increasesAir motion is horizontalAirplanes fly here
7 Mesosphere Thermosphere 50-80 km (30-50 miles)Middle atmosphere – Air thin, pressure low,Need oxygen to live in this region. Air quite cold -90°C (-130°F) near the top of mesosphereThermospherekm ( miles)Very few atoms and molecules in this region.Intense UV – breaks O2 and N2 bondsInternational Space Station is here
8 Greenhouse EffectGreenhouse effect – the trapping of infrared radiation from the sun by gases in earth’s atmosphere which warms the planetRaises earth’s temp to an average of 59 ⁰F. Without the greenhouse effect, the average temp would be 0⁰F.
11 Greenhouse Gases CO2 – most abundant greenhouse gas (GHG) Sources: burning fossil fuels, deforestationIce cores have shown that CO2 increasing in atmosphere – 35% higher than pre-Industrial Rev.Ocean acts as “sink,” absorbing large amounts.Vegetation acts as a sink (until it dies or is cut down)1 kg burned fossil fuels = 3 kg CO2
12 Vostok Ice Core Deepest drilling of ice took place. The ice removed was nearly a half a million years old.Graph = CO2 levels going back to over 400,000 years before present.The (kyr BP) means kilo=1,000 years Before Present.CO2 rises and falls about every 100,000 years.At present we are at a high point again.
13 Global Warming/climate change Global warming – increase in Earth’s average surface temp. caused by an increase in greenhouse gases“runaway greenhouse effect”Earth’s average temperature has risen 1 ° F in last 100 years.Some argue natural fluctuation; however, corresponds w/ rising greenhouse gases
14 CO2 - Did you know…Burning 1 gallon of gasoline produces 9 kg of carbon dioxide?Using one kWh of electricity from a coal-fired generating plant produces 1 kg of carbon dioxide?Burning 100 cubic feet of natural gas produces 5.5 kg of carbon dioxide?1 kg= 2.2 pounds So 1 gallon produces almost 20 pounds of CO2
15 The Jones FamilyComplete the worksheet to see how the Jones family contributes to greenhouse gas emissions.
17 CO2 Emissions Countries: Per Capita: Largest emitters: China (6534 million metric tons): US (5833): Russia (1729): India (1495): Japan (1214)Per Capita:Australia tons (437, country)US tonsChina – 4.91India: 1.31
18 Other Greenhouse Gases Methane (CH4) – 21 times more warming effect than CO2 and increasing at 8 times the rate.Methane production is faster than broken downMain sources are wetlands, rice fields, fossil fuels, livestock, and landfillsRemains in the air about 12 years
19 Greenhouse Gases Nitrous oxides – slow to breakdown (120 yrs) Sources are fossil fuels, fertilizers, deforestationCFCs– slow breakdown; absorb 10,000 X more infrared than CO2 (100 + years)Sources are foams, aerosols, refrigerants, solvents, air conditionersWater vapor – Warmed by CO2, the atmosphere is thus able toabsorb more water vapor. Andthat water vapor, in turn, causesfurther warming—it amplifies the effects of carbon dioxide.
20 Global average temperatures - surface temperatures collected from land and ocean-based stations . Compiled by the Climatic Research Unit of the University of East Anglia and the Hadley Centre of the UK Meteorological Office.
21 Predicted Results Of Global Warming Weather patterns will change - more hurricanes, typhoons, flooding and droughtsAgriculture – weather patterns will move farther north, shifting farmlandSea Levels - polar regions warm, icebergs melt, sea levels rise. Warming water also expands. Coastal areas may flood(Walrus, tiger, Alaska)
22 Melting of Alaska’s Muir Glacier between 1948 and 2004
23 Predicted Results Of Global Warming Human health will be affectedmore infectious diseases.Diseases that normally occur near equator will move northward. Diseases spread by mosquitoes and other insects due to warmer/wetter climates.
24 Predicted Results Of Global Warming Plant and animal species may migrate to maintain their preferred habitatsNot all plants can adapt- cannot disperse their seeds adequatelyCertain birds/fishes may migrateNot all can adapt- ponds will dry up, land-locked fish cannot seek colder riversThose that cannot adapt/migrate may experience regional extinctionBlue winged teal
25 WHAT DO YOU REMEMBER???? 1. List 4 greenhouse gases. 2. Without the greenhouse effect, Earth’s temperature would be ____F instead of ____F.3. Write the layers of the atmosphere starting with the one closest to Earth.4. In which layer is the ozone layer?5. In which layer does weather occur?
26 6. What is the most common greenhouse gas. 7 6. What is the most common greenhouse gas? 7. Which ghg comes from landfills, cows and wetlands? 8. List 2 “sinks” for carbon dioxide- this means what 2 things store large amounts of CO2 9. Which country emits the most CO2? 10. List 4 possible results of global warming.
28 Albedo & Global Warming (albedo= ability of a surface to reflect light) Rising global temperatures cause greater evaporation of water vapor into the atmosphereWater vapor is a powerful greenhouse gas, so an increase in water vapor might produce more warming.ORMore water vapor might cause more clouds to form, increasing Earth's overall albedo, & reflecting incoming sunlight back into space.This would provide a net cooling effect.Might possibly induce a period of "global cooling"
29 Projected Effects of Global Warming and the Resulting Changes in Global Climate
30 Global Cooling Global cooling: natural Planetary albedo – low, thick clouds reflect sunlight, prevent warmingVolcanoes – dust reflect radiationSulfate aerosols – from pollutants, create haze, reflecting sunlight
31 Cap and Trade SystemThe goal: To steadily reduce carbon dioxide and other greenhouse gas emissions economy-wide in a cost-effective manner.The cap: Each large-scale emitter, or company, will have a limit on the amount of greenhouse gas that it can emit.The trade: It will be cheaper or easier for some companies to reduce their emissions below their required limit than others. These more efficient companies, who emit less than their allowance, can sell their extra permits to companies that are not able to make reductions as easily.
32 Output solutions Massive global tree planting; how many? Wangari MaathaiGreat Wall of Trees: China and AfricaPlant fast-growing perennials on degraded landCapturing and storing CO2
34 We Can Prepare for the Harmful Effects of Climate Change Reduce greenhouse gas emissions as much as possibleMove people from low-lying coastal areasLimit coastal buildingRemove hazardous material storage tanks away from the coastGenetically engineer crops more tolerant to droughtStockpile 1–5 years of key foodsWaste less waterConnect wildlife reserves with corridors
35 REVIEW 1. Name the 5 greenhouse gases. 2. What is the main greenhouse gas?3. Why is the greenhouse effect good for our planet? Why is it harmful?4. Name 3 sources of CO2 and CH4.5. Name 2 sinks for CO2.6. List 5 effects of global warming.7. List 5 things you can do to reduce global warming.8. How can we prepare for global warming?9. Name 3 sources of global cooling.
37 THE OZONE LAYER O3 Located in the stratosphere Absorbs most of the UV light from the sunUV light can cause genetic damage to living organisms- can cause skin cancer, faster aging, and cataracts, can kill one-celled organisms (phytoplankton) that live in the surface of the ocean, and interfere with photosynthesis, resulting in lower crop yieldsThe ozone in the stratosphere acts as a sunscreen for Earth and its inhabitants.
38 OZONE EATERSCFCs (Chlorofluorocarbons) – used in refrigerants, air conditioners, styrofoam and propellants because they are chemically stable- they do not break down into other substances or combine with other substances.They are unreactive, odorless, nonflammable, nontoxic, noncorrosive and inexpensive to make.BUT, they do break apart in the stratosphere.
39 CFCsCFCs that are released in the troposphere can take years to float into the stratosphere.One single chlorine atom can destroy 10,000 + ozone molecules and remain in the stratosphere years!
40 STOPPING THE OZONE EATERS 75-85% of the ozone loss was from CFCs and other ozone depleting chemicals CFC containing products have been banned, and the ozone hole is getting smaller.CFCs remain active for more than 30 years, so it will take decades for the layer to recover THE NUMBER 1 SOURCE OF CFCs IS LEAKING AIR CONDITIONERS!
41 CFCsA greenhouse gas AND an ozone-depleting chemical.
43 REVIEW1. In what layer of the earth’s atmosphere is the ozone layer? 2. Why is the ozone layer beneficial? 3. What is the main chemical that affects the ozone layer? 4. Why was this chemical used in so many products? 6. What is the main source of CFC emissions?
44 You fill your tank with 13 gallons of gas You fill your tank with 13 gallons of gas. How much CO2 will be produced by burning this amount of CO2?13 gallons X 20 poundsCO2 = pounds gallonHow much CO2 is produced if you use 150 kWh of electricity in a month?150 kWh x 2 pounds = pounds CO kWh
45 The average amount of CO2 per capita produced in America is 19 The average amount of CO2 per capita produced in America is 19.8 tons, which is 39, 600 pounds!