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5.2 Greenhouse Effect

5.2 Greenhouse Effect. 5.2.1 Draw & Label! Carbon Cycle. CARBON. 1 of main elements of organic molecs (carbs, ptns, lipids) found in 1 of 4 “pools” Biosphere Ocean Atmosphere Sediment Moved b/w them by biolog., geochem., industrial processes. Carbon Cycle Processes. Photosynthesis

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5.2 Greenhouse Effect

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  1. 5.2 Greenhouse Effect

  2. 5.2.1 Draw & Label! Carbon Cycle

  3. CARBON • 1 of main elements of organic molecs (carbs, ptns, lipids) • found in 1 of 4 “pools” • Biosphere • Ocean • Atmosphere • Sediment • Moved b/w them by biolog., geochem., industrial processes

  4. Carbon Cycle Processes • Photosynthesis • Terr./aquatic; CO2 (atmosph/dissolved) removed & fixed into org cmpds • Respiration • Metabolize org molecs, release CO2 • Feeding • C through trophic levels • Fossilization • C trapped in sediment as coal, gas, oil • Combustion • Burning of fossil fuels/biomass, release CO2

  5. 5.2.3 EXPLAIN Atmospheric gases & greenhouse effect • Greenhouse effect: • NATURAL process • creates moderate temps on earth (life’s adapted) • much less CO2 vs. Venus (200,000x more, sfc temp = ~20x higher • Without it... avg global temperature would be -17 C

  6. a) Short wave solar radiation (light) • b) light penetrates the atmosphere and passes through the molecules of the atmosphere • c) Absorption by the ground and conversion to long wave infrared radiation (heat) • d)This warms the planet • e) Some infrared is lost to space as heat • f) Atmospheric gases particularly water vapor, carbon dioxide, methane and CFC's • g) Greenhouse gases absorb infra-red radiation and scatter this rather than letting it escape to space. In effect this traps the heat energy. • h) Some light reflects off the outer surface of the atmosphere and never enters

  7. ENHANCED G’hse. Effect • Human activities may be increasing CO2 levels & other G. gases (methane, N oxides) • May lead to increased global temps and climate change

  8. ENHANCED G’hse. Effect Increased greenhouse gases will increase the particles (f) in the diagram. • more IR will be absorbed, scattered and retained as heat • Avg global temps will rise. • Some models: 40C in next 50 years • predicted to cause global climate changes • “global warming” but while avg global temps rise, local effects may vary

  9. 5.2.2 ANALYZEHistorical Records—Atmospheric Gases • Trends: • indicators of potential climate change • Mauna Loa, HI since 1958 • Now worldwide database: http://cdiac.ornl.gov/trends/co2/sio-keel.htm Search “trace gas measurements”

  10. Data Analysis • CO2’s released unevenly around world • Distribution of Vegetation • Lots of assumptions, factors affecting data analysis • BASIC TREND: increase • Ancient icecoredata—longer database, variety of sources

  11. Ice Cores: Bubbles trapped in ice, 1000s yrs ago! • Temp determined by O isotopes (16:18) • Clear correlation b/w atm CO2 & temperature • DOESN’T mean causation • Levels today higher than ever in past • Dashed blue = extrapolation

  12. 5.2.4 OUTLINE Precautionary Principle • “If the effects of human-induced change would be large, perhaps catastrophic, those responsible for the change must prove that it will not do harm before proceeding.”

  13. PRECAUTIONARY Principle • Obligation actually falls on accused causers of climate change/enhanced greenhouse effect to show their actions are NOT damaging • If we wait til it’s proven....too late to reduce impacts • Better to respond now, even if in long term it turns out that case can’t be made!

  14. 5.2.5 EVALUATE P.P. and Greenhouse

  15. Hmmm-- • Skeptic approach: • envtalists need to give conclusive evidence that ‘polluters’ are causing the harm • PP: • ‘polluters’ need to demonstrate that their actions DO NOT cause harm—govts, industries, communities, individuals!!

  16. Climate Effects—Predictions • Increased freq & intensity of droughts • Flooding • higher rainfalls, more snowmelts, rising sea levels • Declines in food production • Increased disease— • (generally reduced by cold winters)... • Malaria & Dengue fever CURRENTLY extending their distribution!  • More extreme weather • Loss of biodiversity Sea level simulation

  17. External Links to websites of climate change. • Weathervane, Environet, Climateark, GCRIO, UCSUSA, NET External Links to reducing your carbon foot print • Climatecrisis: calculate your carbon footprint. • Energy efficient appliances find out about reducing your energy demands in the house hold. • Simply insulate further information on positive responses to reducing your carbon foot print. • Cutting energy costs 10 ways to reduce your energy costs. • Energy Audit a self help guide to performing an energy audit on your home. • Standby energy leakage on those appliances that 'leak' power when left to stand-by. • Alternative energy sources alternative power sources to fossil fuels. • maximize fuel efficiency from your car making the most of the fuel in your driving. • Hybridcars how hybrids work and a comparison with other methods. • Alternative car fuels Biodiesel, ethanol and more to put in your tank. • Fuel cell vehicles Hydrogen power fuel cells Vulnerability and Adaptation to Climate Change in Developing Countries • article by Chris Ward (30th July 2007) for the World Resources Institute, considers fact that some are working towards own methods of adapting to climate change rather than how they will reduce climate change: • 'Current scientific evidence shows, however, that some human-induced climate change is now inevitable and is in fact already occurring. which regions and groups are most vulnerable to predicted climate flux, how they might adapt to it

  18. 5.2.6 OUTLINE Greenhouse & Arctic • Bill Heal, The Arctic is an Ecosystem Article • “Predicting changes over the next 50-100 yrs is difficult!...Most recent model...mean annual temp of Arctic will rise about 4 C this century... • ...coniferous forest will expand –at expense of tundra • Tundra will be ½-ed by 2100 • Will continue to be C-sink b/c increased growth of forest will exceed increased decomposition

  19. Google EarthClimate Change Tour

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