MET 112 Global Climate Change - Lecture 9GoalsSlide 3Slide 4An Earth System PerspectiveHydrosphereSlide 7Land SurfacesBiosphereSlide 10InteractionsCarbon: what is it?Carbon: where is it?Carbon conservationThe Carbon CycleSlide 16Slide 17Short Term Carbon CycleSlide 19Slide 20Carbon exchange (short term)Slide 22How do we measure the short-term CO2 cycle?Slide 24CO2 Flux: Ecosystem ‘Breathing’Slide 26Slide 27Slide 28Long Term Carbon CycleWhere is most of the carbon today?Slide 31Granite (A Silicate Rock)Limestone (A Carbonate Rock)Silicate-to-Carbonate ConversionSlide 35Changes in chemical weatheringEarth vs. VenusSubjuction/VolcanismSubductionVolcanic EruptionOrganic Carbon Burial/Oxidation of Buried CarbonBuried organic carbon (1)Organic Carbon Burial ProcessOxidation of Buried Organic CarbonSlide 45Slide 46Slide 47The (Almost) Complete Long-Term Carbon CycleSlide 49Slide 50MET 112 Global Climate Change - Lecture 9The 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 cycleThe Earth’s history can be characterized by different geologic events or eras.An Earth System PerspectiveEarth composed of:–Atmosphere–Hydrosphere–Cryosphere–Land Surfaces–BiosphereThese ‘Machines’ run the EarthHydrosphere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 downLand 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)The 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 ExchangesHow do we measure the short-term CO2 cycle?–To determine the ecosystem exchange of CO2 we must measure the flux of CO2 between the biosphere and atmosphere.–These measurements are routine and there is a network of stations that measure CO2 fluxes around the world.How do we measure the short-term CO2 cycle?–Ecosystems ‘breathe’ CO2 in and out. –To determine the ecosystem exchange of CO2 we must measure the flux of CO2 between the biosphere and atmosphere.–These measurements are routine and there is a network of stations that measure CO2 fluxes around the world.CO2 Flux: Ecosystem ‘Breathing’ CO2 ExchangeCO2 Flux: Ecosystem ‘Breathing’ Fast, 3-D AnemometerFast, CO2 sensor(ms-1)(mg m-3)CO2 Flux: Ecosystem ‘Breathing’ CO2 Flux:CO2 (ρ)concentrationVertical Velocity perturbation (w’)2COcF w r��=Flux = Eddy CovarianceTo measure: Need fast velocity and CO2 measurements!=(ms-1) x (mg m-3) =mg m-2 s-1CO2 Flux: Ecosystem ‘Breathing’ H.P. Schmid (2000)Long Term Carbon CycleCarbon is slowly and continuously being transported around our earth system.–Between atmosphere/ocean/biosphere –And the Earth’s crust (rocks like limestone)The main components to the long term carbon cycle:Where is most of the carbon today?Most Carbon is ‘locked’ away in the earth’s crust (i.e. rocks) as –Carbonates (containing