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Learning Targets: I can model and explain the relationships and energy flow existing in various Earth systems (atmosphere) I can explain factors that cause the dynamic balance in the atmosphere to change. 2
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41. What GHG’s are naturally present in the atmosphere? water vapor, ozone, carbon dioxide, methane, and nitrous oxide 4
Total Emissions in 2011 = 6,702 Million Metric Tons of CO 2 equivalent Million Metric Tons of CO 2 equivalent Gases that trap heat in the atmosphere are called greenhouse 5
* Land Use, Land-Use Change, and Forestry in the United States is a net sink and offsets approximately 14% of these greenhouse gas emissions. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: Land Use, Land-Use Change, and Forestry Greenhouse gases trap heat and make the planet warmer. Total Emissions in 2011 = 6,702 Million Metric Tons of CO 2 equivalent Million Metric Tons of CO 2 equivalent U.S. Greenhouse Gas Emissions in
42.Some GHG’s are synthetic chemicals that are emitted only as a result of human activity. 43. Anthropogenic means human. 7
Click on link to see slide show of 10 ten sources of greenhouse gases greenhouse-gases-gallery greenhouse-gases-gallery Click on link below to see GHG emissions for Hardin County 8
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44. Complete the table below for these common Greenhouse Gases, GHGs. Carbon dioxide Formula CO 2 Sources - combustion of carbon-based fuels - the decay of biomass Natural Sources - volcanic eruptions, - respiration of organic matter in natural ecosystems - natural fires - exchange of dissolved CO 2 with the oceans Human sources (a) fossil fuel combustion (b) deforestation and land use changes (such as converting agricultural land or forests to urban development) 11
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Methane Formula CH 4 Sources - anaerobic decay of organic material in landfills, wetlands, and rice fields - enteric fermentation in the digestive tracts of ruminant animals such as cattle, goats, and sheep - manure management - wastewater treatment - fossil fuel combustion - leaks from natural gas transportation and distribution systems - abandoned coal mines. 14
to-electricity-projects.html 15
Nitrous Oxide Formula N 2 O Sources - fertilizer use - animal waste management - fossil fuel combustion - industrial activities. 16
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Hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) are synthetic chemicals that are used in a variety of industrial production processes Sources - semiconductor manufacturing -PFCs - by-product of aluminum smelting - substitutes for ozone-depleting chlorofluorocarbons (CFCs) in refrigeration and foam-blowing for insulation CFCs are being phased out under the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. 18
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45.What happens when atmospheric GHG concentrations increase? Earth temporarily traps infrared radiation more efficiently, so the natural radiative balance is disturbed until its surface temperature rises to restore equilibrium between incoming and outgoing radiation. Earth temporarily traps infrared radiation more efficiently, so the natural radiative balance is disturbed until its surface temperature rises to restore equilibrium between incoming and outgoing radiation
Importance of human-produced greenhouse gases. Courtesy Marian Koshland Science Museum of the National Academy of Sciences 21