Presentation on theme: "Greenhouse gases, global warming and the ozone layer ATMOSPHERE AND CLIMATE."— Presentation transcript:
Greenhouse gases, global warming and the ozone layer ATMOSPHERE AND CLIMATE
The Atmosphere Is a thin layer of gases that surrounds the earth Extends thousands of km above the surface The reason there is life on Earth – we are protected from most of the suns radiation Allows some light to reach the surface, supplying energy and allowing photosynthesis (O 2 and CO 2 ) 78% nitrogen, 21% oxygen, 1%= water vapor, argon, carbon dioxide, neon, helium, and other gases
HOW PHOTOSYNTHESIS CHANGED THE ATMOSPHERE The early atmosphere contained little oxygen. Bacteria appeared about 4 bya and evolved the ability to perform photosynthesis 6CO 2 + 6H 2 O + sun energy C 6 H 12 O 6 + 6O 2
The 4 Layers
Troposphere – 75–80% of the earths air mass – Closest to the earth's surface – 0-11 km above sea level – Chemical composition of air Nitrogen 78% Oxygen 21% H 2 0, CO 2, trace amounts of others (Ar) – Weather, climate and all life forms exist here – As altitude increases, temperature decreases
Stratosphere km (6-30 miles) above Earth's surface – Similar composition to the troposphere, with 2 exceptions Much less water (1/1000) O 3, ozone layer As altitude increases, temperature increases Air motion is horizontal Airplanes fly here
Mesosphere km (30-50 miles) km (30-50 miles) Middle atmosphere – Air thin, pressure low, Middle atmosphere – Air thin, pressure low, Need oxygen to live in this region. Air quite cold -90°C (-130°F) near the top of mesosphere Need oxygen to live in this region. Air quite cold -90°C (-130°F) near the top of mesosphereThermosphere km ( miles) Very few atoms and molecules in this region. Intense UV – breaks O 2 and N 2 bonds International Space Station is here
Greenhouse Effect Greenhouse effect – the trapping of infrared radiation from the sun by gases in earths atmosphere which warms the planet Raises earths temp to an average of 59 F. Without the greenhouse effect, the average temp would be 0F.
Greenhouse Gases CO 2 – most abundant greenhouse gas (GHG) Sources: burning fossil fuels, deforestation Ice cores have shown that CO 2 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 CO 2 1 kg burned fossil fuels = 3 kg CO 2
Vostok Ice Core Deepest drilling of ice took place. The ice removed was nearly a half a million years old. Graph = CO 2 levels going back to over 400,000 years before present. The (kyr BP) means kilo=1,000 years Before Present. CO 2 rises and falls about every 100,000 years. At present we are at a high point again.
Global Warming/climate change Global warming – increase in Earths average surface temp. caused by an increase in greenhouse gases runaway greenhouse effect Earths average temperature has risen 1 ° F in last 100 years. Earths average temperature has risen 1 ° F in last 100 years. Some argue natural fluctuation; however, corresponds w/ rising greenhouse gases
CO 2 - 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 CO 2
The Jones Family Complete the worksheet to see how the Jones family contributes to greenhouse gas emissions.
CO 2 Emissions Countries: – Largest emitters: China (6534 million metric tons): US (5833): Russia (1729): India (1495): Japan (1214) Per Capita: – Australia tons (437, country) – US tons – China – 4.91 – India: 1.31
Other Greenhouse Gases Methane (CH 4 ) – 21 times more warming effect than CO 2 and increasing at 8 times the rate. Methane production is faster than broken down Main sources are wetlands, rice fields, fossil fuels, livestock, and landfills Remains in the air about 12 years
Greenhouse Gases Nitrous oxides – slow to breakdown (120 yrs) – Sources are fossil fuels, fertilizers, deforestation CFCs– slow breakdown; absorb 10,000 X more infrared than CO 2 (100 + years) – Sources are foams, aerosols, refrigerants, solvents, air conditioners Water vapor – Warmed by CO 2, the atmosphere is thus able to absorb more water vapor. And that water vapor, in turn, causes further warmingit amplifies the effects of carbon dioxide.
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.Climatic Research UnitUniversity of East AngliaHadley CentreUK Meteorological Office
Predicted Results Of Global Warming Weather patterns will change - more hurricanes, typhoons, flooding and droughts Agriculture – weather patterns will move farther north, shifting farmland Sea Levels - polar regions warm, icebergs melt, sea levels rise. Warming water also expands. Coastal areas may flood (Walrus, tiger, Alaska)
Melting of Alaskas Muir Glacier between 1948 and 2004
Predicted Results Of Global Warming Human health will be affected – more infectious diseases. – Diseases that normally occur near equator will move northward. Diseases spread by mosquitoes and other insects due to warmer/wetter climates.
Predicted Results Of Global Warming Plant and animal species may migrate to maintain their preferred habitats Not all plants can adapt- cannot disperse their seeds adequately Certain birds/fishes may migrate Not all can adapt- ponds will dry up, land-locked fish cannot seek colder rivers Those that cannot adapt/migrate may experience regional extinction Blue winged teal
WHAT DO YOU REMEMBER???? 1. List 4 greenhouse gases. 2. Without the greenhouse effect, Earths 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?
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 CO 2 9. Which country emits the most CO 2 ? 10. List 4 possible results of global warming.
Teachers domain- global warmingglobal warming
Albedo & Global Warming (albedo= ability of a surface to reflect light) Rising global temperatures cause greater evaporation of water vapor into the atmosphere Water vapor is a powerful greenhouse gas, so an increase in water vapor might produce more warming. OR More 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"
Projected Effects of Global Warming and the Resulting Changes in Global Climate
Global Cooling Global cooling: natural Planetary albedo – low, thick clouds reflect sunlight, prevent warming Volcanoes – dust reflect radiation Sulfate aerosols – from pollutants, create haze, reflecting sunlight
Cap and Trade System The 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.
Output solutions – Massive global tree planting; how many? Wangari Maathai Great Wall of Trees: China and Africa – Plant fast- growing perennials on degraded land – Capturing and storing CO 2
Fifteen Ways to Cut CO 2 Emissions
We Can Prepare for the Harmful Effects of Climate Change Reduce greenhouse gas emissions as much as possible Move people from low-lying coastal areas Limit coastal building Remove hazardous material storage tanks away from the coast Genetically engineer crops more tolerant to drought Stockpile 1–5 years of key foods Waste less water Connect wildlife reserves with corridors
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 CO 2 and CH Name 2 sinks for CO 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.
VIDEO: NOVA: WHATS UP WITH THE WEATHER
O 3 O 3 Located in the stratosphere Located in the stratosphere Absorbs most of the UV light from the sun Absorbs most of the UV light from the sun – UV 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 yields The ozone in the stratosphere acts as a sunscreen for Earth and its inhabitants. The ozone in the stratosphere acts as a sunscreen for Earth and its inhabitants. THE OZONE LAYER
OZONE EATERS CFCs (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.
CFCs CFCs 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!
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. 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!
CFCs A greenhouse gas AND an ozone-depleting chemical.
video clip one/s from Teachers Domain phy03_vid_greenhouse2/http://www.teachersdomain.org/asset/ phy03_vid_greenhouse2/ vid_aerosols/ vid_aerosols/
REVIEW 1. In what layer of the earths 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?
You fill your tank with 13 gallons of gas. How much CO 2 will be produced by burning this amount of CO 2 ? 13 gallons X 20 poundsCO 2 = 260 pounds 1 gallon How much CO 2 is produced if you use 150 kWh of electricity in a month? 150 kWh x 2 pounds = 300 pounds CO 2 1 kWh
The average amount of CO 2 per capita produced in America is 19.8 tons, which is 39, 600 pounds!