METR112 Global Climate ChangeSlide 2MET 112 Global Climate Change -PaleoclimateSlide 5Slide 6Slide 7Natural Climate ChangeSlide 9Slide 10Slide 11Slide 12Slide 13External ForcingSlide 15Solar VariationsTHE SOLAR CYCLETHE MAUNDER MINIMUMSlide 19Little Ice AgeSlide 21Slide 22Orbital changesSlide 24Slide 26Slide 28Slide 29Slide 30Internal ForcingMETR112-Climate ModelingSlide 33Slide 34Slide 35Slide 36Ocean: salinity distribution closely relates to precipitation evaporationSlide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Climate FeedbacksPositive FeedbacksStability versus instabilityClimate StabilitySlide 55Slide 56Ice-Albedo Feedback (Cooling)Slide 59Fill in the blanksSlide 62Water Vapor Feedback (Cooling)Negative FeedbacksPossible Role of Cloud in Warming or Cooling the AtmosphereWhich feedback is positive?MET 112 Global Climate Change - Lecture 11Slide 68History of Ozone Depletion: connection between human and natureSlide 70Ozone Hole RecipeWhat is being done about ozone depletion?Slide 73Is the Montreal Protocol working?Slide 75What is the connection between ozone depletion and global warming?Slide 77Slide 78Drinkable Water (Freshwater)Slide 80Economic interestLecture SummarySlide 83MET 112 Global Climate Change: Lecture 12The UN Framework Convention on Climate ChangeIPCC Assessment ReportSlide 87Slide 88Emission ScenariosScenariosSlide 91Future Predictions: TemperatureSlide 94Land areas are projected to warm more than the oceans with the greatest warming at high latitudesSome areas are projected to become wetter, others drier with an overall increase projectedSea LevelSea Level RiseSlide 101QuestionsMitigation of climate changeSlide 104The Kyoto ProtocolKyoto TargetsSlide 107Kyoto Targets: Developing countriesThe Kyoto MechanismsKyoto Protocol MechanismsEmissions TradingSlide 112Slide 114Class ParticipationSlide 116METR112 Global Climate ChangeProfessor Menglin JinSan Jose State UniversityDecember 1, 2008Scope for Final Exam: Materials discussed after the mid-term Materials: Lectures (Lectures 8-12) most important!Homework 3 and 4 very importantVideo will be only briefly touchedExam format: half multiple choiceshalf short sentence answersWeight of Final exam: will be scored as 100 pointsbut will be weighted as 35% of the total class grade3 MET 112 Global Climate MET 112 Global Climate ChangeChangeMET 112 Global Climate Change -Natural Climate ForcingProfessor Menglin JinSan Jose State UniversityOutline –Paleoclimate – temperature and CO2Natural forcing for temperature changeFeatures for Glacier and inter-glacier Activity4 MET 112 Global Climate MET 112 Global Climate ChangeChangePaleoclimateA lead to5 MET 112 Global Climate MET 112 Global Climate ChangeChangeEarth geological time scalePaleo : Greek root means “ancient”Modern age, ice age, last 2 million yearsAge of dinosaursFrom the formation of earth to the evolution of macroscopic hard-shelled animalsAnimal explosion of diversity6 MET 112 Global Climate MET 112 Global Climate ChangeChangeCosmic rays produce C14C14 has half-life of 5730 years and constitutes about one percent of the carbon in an organism.When an organism dies, its C14 continues to decay.The older the organism, the less C14C14 and O18 proxyO18 is heavier, harder to evaporate. As temperature decreases (in an ice age), snow deposits contains lessO18 while ocean water and marine organisms (CaCO3) contain more O18 The O18/ O16 ratio or δO18 in ice and marine deposits constitutes a proxy thermometer that indicates ice ages and interglacials.Low O18 in ice indicates it was deposited during cold conditions worldwide, while low O18 in marine deposits indicates warmth C14 dating proxyO18 temperature proxy8 MET 112 Global Climate MET 112 Global Climate ChangeChangeNatural Climate ChangeExternal Forcing:– Internal Forcing:– The agent of change is outside of the Earth-atmosphere systemThe agent of change is within the Earth-atmosphere system itself9 MET 112 Global Climate MET 112 Global Climate ChangeChangeContinental drifhttp://www.mun.ca/biology/scarr/Pangaea.htmlIn 1915, German scientist Alfred Wengener first proposed continental drif theory and published book On the Origin of Continents and OceansContinental drif states:In the beginning, a supercontinent called Pangaea. During Jurrasic, Pangaea breaks up into two smaller supercontinents, Laurasia and Gondwanaland,. By the end of the Cretaceous period, the continents were separating into land masses that look like our modern-day continents10 MET 112 Global Climate MET 112 Global Climate ChangeChangeConsequences of continental drif on climatePolarward drifing of continents provides land area for ice formation  cold climateAntarctica separated from South America reduced oceanic heat transport  cold climateJoint of North and South America strengthens Gulf Stream and increased oceanic heat transport  warm climateUplif of Tibetan Plateau  Indian monsoon11 MET 112 Global Climate MET 112 Global Climate ChangeChangeWarm during CretaceousPsulsen 2004, natureThe Arctic SST was 15 oC or higher in mid and last Cretaceous. Global models can only represent this feature by restoring high level of CO2High CO2 may be responsible for the initiation of the warmingHigher water vapor concentration leads to increased latent heat transport to high latitudesDecreased sensible heat transport to high latitudes results from decreased meridional temperature gradient Thermal expansion of sea water increased oceanic heat transport to high latitudesbeing the last period of the Mesozoic era characterized by continued dominance of reptiles, emergent dominance of angiosperms, diversification of mammals, and the extinction of many types of organisms at the close of the period Cretaceous13 MET 112 Global Climate MET 112 Global Climate ChangeChangeShort-term forcing: The kinetic energy of thebollide is transferred to the atmosphere sufficient to warm the global mean temperature near the surface by 30 K over the first 30 days The ejecta that are thrown up by the impact return to Earth over several days to weeks produce radiative heating. Long-term forcing: Over several weeks to months, a global cloud of dust obscures the Sun, cooling the Earth’s surface, effectively eliminating photosynthesis and stabilizing the atmosphere to the degree that the hydrologic cycle is cut off. The sum of these effects together could kill most