Chapter 10 Global EffectsChapter 10+ OverviewiClicker QuestionSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14iClicker Question:Slide 16Slide 17Slide 18Slide 19Temperature MeasurementsSlide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51InundationSlide 53Slide 54Slide 55Measuring Your Carbon FootprintConservation: Three ExamplesEnergy Efficiency: Two ExamplesSlide 59Slide 60Slide 61Slide 62Slide 63Slide 64Slide 65Slide 66Slide 67Slide 68Slide 691Chapter 10Global EffectsLecture #21HNRS 228Energy and the EnvironmentAdapted from UNM and USGS2Chapter 10+ Overview•Earth as a planet•The polar regions and sea ice effects•The stratospheric ozone situation•Another look at greenhouse gasses•Climate change•Global warming3iClicker QuestionWhich of the following layers of the atmosphere is highest above the surface of the Earth?A TroposphereB StratosphereC ThermosphereD MesosphereE Ozone Layer4iClicker QuestionWhat is the primary ingredient of the Earth's atmosphere?A NitrogenB OxygenC Nitrogen and oxygen in equal partsD HydrogenE Carbon dioxide5iClicker QuestionIn what part of the atmosphere does weather occur?A HydrosphereB StratosphereC IonosphereD TroposphereE All of the above6iClicker QuestionHow rapidly a planet loses its atmosphere depends on the planet's•I. mass•II.atmospheric composition•III. temperature•IV. rotation periodA I & IIB III & IVC I, II, & IIID II, III, & IVE I, II, III, & IV7iClicker QuestionThe presence of Earth’s magnetic field is a good indication thatA there is a large amount of magnetic material buried near the North Pole.B there is a quantity of liquid metal swirling around in the Earth's core.C the Earth is composed largely of iron.D the Earth is completely solid.E there are condensed gasses in the core of the Earth.8The Earth9General FeaturesMass: MEarth = 6 x 1027 gRadius: REarth = 6378 kmDensity:  = 5.5 g/cm3Age: 4.6 billion years10Earth's Internal StructureCrust: thin. Much Si and Al(lots of granite). Two-thirds covered by oceans.How do we know? Earthquakes. See laterMantle is mostly solid, mostly basalt (Fe, Mg, Si). Cracks in mantle allow molten material to rise => volcanoes.Core temperature is ~6000 K. Metallic - mostly nickel and iron. Outer core molten, innercore solid.Atmosphere very thin11Earth's Atmosphere78% Nitrogen21% Oxygengas is ionized by solar radiationozone is O3 , which absorbs solar UV efficiently, thusheating stratospherecommercial jet altitudesroom temperatureOriginal atmosphere changed over time. Atmosphere today is largely due to volcanoes and life (especially plant).12IonosphereParticles in the upper reaches of the atmosphere are ionized by the sun.Radio signals below ~20 MHz can “bounce” off the ionosphere allowing communication “over the horizon”13ConvectionEarth's surface heated by Sun. What would happen if it couldn't get rid of the energy as fast as it gets in?Convection causes both small-scale turbulence and large scale circulation patterns. It also occurs within Earth, on other planets, and in stars.Convection also occurs when you boil water, or soup. Think of Earth's surface as a boiling pot!14The Greenhouse EffectMain greenhouse gases are H2O and CO2 .If no greenhouse effect, surface would be 40 oC cooler!15iClicker Question:The dinosaurs were most likely wiped out by:A: diseaseB: hunting to extinction by cavemenC: a giant meteor impactD: the close passage of another star16iClicker Question:A leading cause of Global Warming is:A: Increased soot (smog) in the atmosphere.B: Increased carbon dioxide in the atmosphere.C: The Earth is getting closer to the sun.D: The luminosity of the sun is steadily increasing.17iClicker Question:The Greenhouse effect would not occur if:A: The Earth had no atmosphere.B: The amount of carbon dioxide doubled.C: We got rid of all the forests.D: The Earth didn’t have an ocean.18Burning carbon-containing fossil fuels produces carbon dioxide.(Combustion)C + O2 CO2PollutionPollutionGlobal Warming: The Greatest Threat © 2006 Deborah L. Williams19CO2: Most Significant Greenhouse GasCO2: Most Significant Greenhouse GasSource: ACIA 2004 Jennifer Allen graphicGlobal Warming: The Greatest Threat © 2006 Deborah L. WilliamsCO2 CH4Humans have increased carbon dioxide (CO2) in the atmosphere by more than 35% since the Industrial Revolution. (National Oceanic and Atmospheric Administration 2006) The most carbon dioxide in 650,000 years. (IPCC 2007)20 Temperature Measurements“Warming of the climate system is UNEQUIVOCAL” (IPCC 2007)Top 11 warmest years on record have all occurred in the last 12 years.(IPCC 2007)2006 warmest year on record in continental US. (NOAA 1/07)21Alaska as Ground Zero for WarmingAlaska as Ground Zero for WarmingIn past 50 years, Alaska: Temperatures haveincreased•4oF overall(National Assessment Synthesis Team) Worldwide:Temperatures haveincreased •Slightly more than 1oF(IPCC 2007) Surface Air Temperature Trends 1942-2003Global Warming: The Greatest Threat © 2006 Deborah L. WilliamsChapman and Walsh, 200422Snow and sea ice reflect 85-90% of sun’s energy.  Ocean surface and dark soil reflect only 10-20%. The Albedo Effect“White shirt versus Black shirt”Why has Alaska warmed the most?Why has Alaska warmed the most?Increased melting of snowand sea iceIncreased melting of snowand sea iceMore of sun’s heat energy is absorbedMore of sun’s heat energy is absorbedMore dark earthand ocean surface is exposedMore dark earthand ocean surface is exposedLand or water warms fasterLand or water warms fasterGlobal Warming: The Greatest Threat © 2006 Deborah L. Williams(ACIA 2004)23Source ACIA, 2004Jennifer Allen AnimationAn area twice the size of Texas has melted away since 1979 (over 20% decrease). (National Snow and Ice Data Center 2005)Ice 40% thinner. (Rothrock,D.A, et al. 1999)Ice only 6 – 9 feet thick at North Pole (NOAA FAQ 2007).Northwest passage opened Aug 21, 2007 Impacts in Alaska1. MeltingMelting Sea IceMelting Sea Ice1978 1983 1988 1993 1998 20039876----| | | | |Arctic Sea Ice Extent (millions of sq. km.) Source: NSIDC, 2005ARCTIC SEA ICE