MET 112 Global Climate Change - Lecture 8GoalsSlide 3An Earth System PerspectiveSlide 5HydrosphereSlide 7CryosphereSlide 9Slide 10Land SurfacesBiosphereInteractions Between Components of Earth SystemWhen ice sheets melt and thus sea levels rise, which components of the earth system are interacting?When water from lakes and the ocean evaporates, which components of the earth system are interacting?Slide 16InteractionsCarbon: what is it?Carbon: where is it?Carbon conservationThe Carbon CycleSlide 22Slide 23Short Term Carbon CycleSlide 25Slide 26Carbon exchange (short term)Slide 28Long Term Carbon CycleSlide 30Where is most of the carbon today?Slide 32Granite (A Silicate Rock)Limestone (A Carbonate Rock)Silicate-to-Carbonate ConversionSlide 36Changes in chemical weatheringEarth vs. VenusSubjuction/VolcanismSubductionVolcanic EruptionOrganic Carbon Burial/Oxidation of Buried CarbonBuried organic carbon (1)Organic Carbon Burial ProcessOxidation of Buried Organic CarbonSlide 46Slide 47Slide 48The (Almost) Complete Long-Term Carbon CycleSlide 50Slide 51MET 112 Global Climate Change - Lecture 8The Carbon CycleDr. Craig ClementsSan José State UniversityGoalsWe want to understand the difference between short term and long term carbon cycle We want to understand the main components of the long term carbon cycleAn Earth System PerspectiveEarth composed of:–Atmosphere–Hydrosphere–Cryosphere–Land Surfaces–BiosphereThese ‘Machines’ run the EarthThe Earth’s history can be characterized by different geologic events or eras.HydrosphereComponent comprising all liquid water– Surface and subterranean (ground water)Fresh/Salt waterThus…lakes, streams, rivers, oceans…Oceans:–Oceans currently cover ~ 70% of earth–Average depth of oceans: 3.5 km–Oceans store large amount of energy–Oceans dissolve carbon dioxide (more later)–Circulation driven by wind systems–Sea Level has varied significantly over Earth’s history–Slow to heat up and cool downCryosphereComponent comprising all ice–Glaciers–Ice sheets:Antarctica, Greenland, Patagonia–Sea Ice–Snow FieldsClimate:–Typically high albedo surface–Positive feedback possibility Store large amounts of water; sea level variations.Greenland Ice Cap 2008Greenland Ice Cap 2008Land SurfacesContinentsSoils surfaces and vegetationVolcanoesClimate:–Location of continents controls ocean/atmosphere circulations–Volcanoes return CO2 to atmosphere–Volcanic aerosols affect climateBiosphereAll living organisms; (Biota) Biota- "The living plants and animals of a region.“ or "The sum total of all organisms alive today”–Marine–TerrestrialClimate:Photosynthetic process store significant amount of carbon (from CO2)Interactions Between Components of Earth SystemHydrologic Cycle (Hydrosphere, Surface,and Atmosphere)–Evaporation from surface puts water vapor into atmosphere–Precipitation transfers water from atmosphere to surfaceCryosphere-Hydrosphere–When glaciers and ice sheets shrink, sea level rises–When glaciers and ice sheets grow, sea level fallsWhen ice sheets melt and thus sea levels rise, which components of the earth system are interacting? 1. Atmosphere-Cryosphere2. Atmosphere-Hydropshere3. Hydrosphere-Cryosphere4. Atmosphere-Biosphere5. Hydrosphere-BiosphereWhen water from lakes and the ocean evaporates, which components of the earth system are interacting? 1. Land Surface – atmosphere2. Hydrosphere-atmosphere3. Hydrosphere-land surface4. Crysophere-Atmosphere5. Biosphere-AtmosphereThe Earth’s history can be characterized by different geologic events or eras.Interactions Components of the Earth System are linked by various exchanges including EnergyWater (previous example)CarbonIn this lecture, we are going to focus on the exchange of Carbon within the Earth SystemCarbon: what is it?Carbon (C), the fourth most abundant element in the Universe, Building block of life. –from fossil fuels and DNA –Carbon cycles through the land (bioshpere), ocean, atmosphere, and the Earth’s interiorCarbon found–in all living things –in the atmosphere –in the layers of limestone sediment on the ocean floor–in fossil fuels like coalCarbon: where is it?Exists:– Atmosphere:–CO2 and CH4 (to lesser extent)–Living biota (plants/animals)–Carbon–Soils and Detritus–Carbon–Methane–Oceans–Dissolved CO2–Most carbon in the deep oceanCarbon conservationInitial carbon present during Earth’s formationCarbon doesn’t increase or decrease globallyCarbon is exchanged between different components of Earth System.The Carbon CycleThe complex series of reactions by which carbon passes through the Earth's –Atmosphere –Land (biosphere and Earth’s crust)–Oceans Carbon is exchanged in the earth system at all time scales-Long term cycle (hundreds to millions of years)-Short term cycle (from seconds to a few years)The carbon cycle has different speedsShort Term Carbon CycleLong Term Carbon CycleShort Term Carbon CycleOne example of the short term carbon cycle involves plants Photosynthesis: is the conversion of carbon dioxide and water into a sugar called glucose (carbohydrate) using sunlight energy. Oxygen is produced as a waste product.Plants requireSunlight, water and carbon, (from CO2 in atmosphere or ocean) to produce carbohydrates (food) to grow.When plants decay, carbon is mostly returned to the atmosphere (respiration)Global CO2Short Term Carbon CycleOne example of the short term carbon cycle involves plants Photosynthesis: is the conversion of carbon dioxide and water into a sugar called glucose (carbohydrate) using sunlight energy. Oxygen is produced as a waste product.Plants requireSunlight, water and carbon, (from CO2 in atmosphere or ocean) to produce carbohydrates (food) to grow.When plants decay, carbon is mostly returned to the atmosphere (respiration)During spring: (more photosynthesis)atmospheric CO2 levels go down (slightly)During fall: (more respiration)atmospheric CO2 levels go up (slightly)Carbon exchange (short term)Other examples of short term carbon exchanges include:Soils and Detritus: -organic matter decays and releases carbonSurface Oceans–absorb CO2 via photosynthesis–also release CO2Short Term Carbon ExchangesLong Term Carbon CycleCarbon is slowly and continuously being transported around our earth