Demystifying Climate Change Session 6 CO2 and Other Greenhouse Gases: Where do they come from? Where do they go? How are they regulated? Burp… OLLI at Illinois Spring 2021 D. H. Tracy [email protected] 418.53 ppm Mar 6, 2021 3/9/21 Climate Change 6 2 Course Outline 1. Building Blocks: Some important concepts 2. Our Goldilocks Earth: a Radiative Balancing Act 3. The Role of the Atmosphere: Greenhouse Gases & Clouds 4. Global Circulation and Dynamics of the Earth System: Oceans, Atmosphere, Biosphere, Cryosphere, People, Lithosphere 5. Natural Variability of the Climate, short and long term. Ice Ages 6. Carbon Dioxide and other Greenhouse Gases: Where do they come from, where do they go, how are they regulated? 7. Impacts and Future Projections for Global Warming -- Uncertainties 8. Amelioration Strategies. The Climate Debate. Policy Options. 3/9/21 Climate Change 6 3 Remember CO2 Saturation? 400ppm CO2 T260K P0.5 L6.4m 100%100% Lesson: Blue: 800 ppm 80% Greenhouse Gases 4 ppm are much more Red: potent, per ppm, 400 ppm 60% when at low 1 ppm concentrations: 40% Not saturated. Absorption of Full Atmosphere Full of Absorption 20% Absorption of Full Atmosphere ofFull Absorption 0% 8.5 9 10 11 12 13 14 15 16 17 18 19 20 Wavelength (mm) Wavelength (m) 3/9/21 Climate Change 6 4 Actual Surface Temperature vs. GH Gas Concentration Doublings Behavior Expected for Linear Increase Minor/Trace Gases ∆T2X TSURF 2x Log Increase Saturation TSKIN setting in 254 K (-2F) Doublings T 0 1 1 1 1 1 /128 x /64 x /32 x /16 x /8 x ¼ x ½x 1x 2x 4x 8x 3/9/21 Climate Change 6 Concentration of GH Gas → 5 ∆T Full Atmosphere: Water Vapor + CO2 Leave A Window at 10-11 m 400ppm CO2 T260K P0.5 L6.4m 100%100% Window 80% Origin of the LW IR Atmospheric CO2 60% Window 40% Absorption of Full Atmosphere Full of Absorption 20% 0% 8 9 10 11 12 13 14 15 16 17 18 19 20 17m-atm H2O T296K P1.0 L17m Wavelength (mm) 100%100% Window 80% 60% H2O 40% Absorption of Full Atmosphere Full of Absorption 20% 0% 4.8 5 6 7 8 9 10 11 12 13 14 15 16 18 20 Wavelength (mm) 3/9/21 Climate Change 6 6 3/9/21 Climate Change 6 7 Radiative Forcing as of 2011 (IPCC AR5) IPCC AR5 SPM-5 3/9/21 Climate Change 6 8 Greenhouse Gas Radiative Forcing as of 2011 (IPCC AR5) Long- lived Gases Short- lived * Gases Watts/m2 relative to 1750 IPCC AR5 SPM-5 3/9/21 *Non-Methane VOC’s Climate Change 6 9 like Ethanol, Acetone, Formaldehyde Earth’s Energy Budget Net solar 240.5 W/m2 Net IR out 239.9 W/m2 Convection into Troposphere Dry Wet Net Absorption 0.6 W/m2 geothermal etc. 3/9/21 0.13 Climate Change 6 10 Water H2O a very important GH Gas -- but not considered a Radiative Forcing agent 3/9/21 Climate Change 6 12 Water Content of Atmosphere Limited by Condensation 140% Changes in Surface Temperature 120% will automatically cause the H H amount of water vapor in the O 100% atmosphere to change. Water Vapor 100% Content of a R.H. 80% T H O Greenhouse T Layer of the 2 Atmosphere 60% T H2O Greenhouse T 50% 40% R.H. 20% 0% Water Feedback -40 -20 0 20 40 60 80 100 120 T (C) Approximately T (F) 0 50 100 150 200 Doubles the Effect of Any Forcing 3/9/21 Climate Change 6 13 Water is on Autopilot • No external intervention could feasibly directly affect H2O vapor content of atmosphere – but indirectly any Forcing can and does affect water vapor • Could the Positive Feedback run away? – Inducing Iceball Earth or – Venus-like Sauna Earth * van der Ent & Tuinenburg (2017) 3/9/21 Climate Change 6 14 Rough Timeline of Past Glaciations Baykonurian Gaskiers Mirinoan Andean-Saharan (Quaternary) Pongola Huronian Antarctic Sturtian Karoo* 0.73 0.53 Hadean 0.33 0.13 -0.08 60 50 40 30 20 10 0 4.5 4 3 2 1 400 100 25 5 0 Billions of Years Ago Millions of Years Ago Snowball Data source: Wikipedia “Late Paleozoic Icehouse” Table Earth? * AKA Late Paleozoic Icehouse 3/9/21 Climate Change 6 15 Sauna Earth? 140% T H2O Greenhouse T 120% H H O Upper layers of T = 254K 100% atmosphere are very SKIN Water Vapor 100% cold (< 254K) due to R.H. Greenhouse effect, so Content of a 80% a water atmosphere collapses from the top. Layer of the It seems that a H2O- Atmosphere 60% only sauna earth is impossible. 50% 40% R.H. 20% Ice & Convection Liquid 0% -40 -20 0 20 40 60 80 100 120 T (C) T (F) 373 K 0 50 100 150 200 3/9/21 Climate Change 6 16 Questions about 140% Greenhouse Gases in General 120% or Water in Particular? 100% ?80% H H O 60% 100% R.H. 40% Long- lived 50% Gases 20% R.H. 0% Short- lived * -40 -20 0 20 40 60 80 100 120 T (C) Gases T (F) 0 50 100 150 200 Climate Change 5 3/2/2021 17 Carbon Dioxide CO2 …the Gorilla in the room 3/9/21 Climate Change 6 18 Elemental Abundances Solar System: Earth Crust: 1. Hydrogen 1. Oxygen Carbon Dioxide CO 2. Helium 2. Silicon 2 3. Oxygen 3. Aluminum 4. Carbon 4. Iron 5. Nitrogen 5. Calcium 6. Neon 6. Sodium 10-15 Carbon 3/9/21 Climate Change 6 19 Elemental Carbon (12C) Forms (Allotropes) Graphene Graphite Diamond C60 Buckminsterfullerene Carbon Nanotubes Amorphous Carbon 3/9/21 Climate Change 6 20 Carbon Compounds Gases Organic Compounds Inorganic Compounds Octane CO 2 Hydrogen Cyanide H C N Methane Calcium Carbonate CH4 Ethanol ++ = Ca CO3 O Propane THC ─ O C ─ C3H6 O 3/9/21 Climate Change 6 21 Carbon Compounds Gases Organic CompoundsPolarizers Inorganic Compounds Chalk Octane CO 2 Hydrogen Cyanide H C N Forams Methane Calcium Carbonate CH4 Ethanol Mollusc ++ = Ca CO3 Shells ++ Ca O THC ─ Propane C ─ C H O 3 6 Limestone Corals O 3/9/21 Climate Change 6 22 Tonnage of Carbon vs. CO2 C 1 Ton of Carbon …. 12 makes CO2 16 16 12 3.7 Tons of CO2 44 3/9/21 Climate Change 6 23 Example: 2020 US Per Capita Carbon Emissions 3.7 tons of Carbon or 13.7 tons of CO2 per capita, per year Le Quere et al, Global Carbon Budget 2018 Fig 5 Earth System Science Data.net edgar.jrc.ec.Europa.eu for 2019 carbonbrief.org for 2020 3/9/21 Climate Change 6 24 1 Gigaton of Carbon 1.09 km (GtC) Willis Tower Chicago Brilliant—cut diamond 3/9/21 Climate Change 6 25 1 Gigaton of Carbon (GtC) Willis Tower Chicago 1 mile 3/9/21 Climate Change 6 26 Carbon Cycle as of 2011 IPCC AR5 WG1 Fig. 6.1 3/9/21 Climate Change 6 27 Permafrost & “Surface” Atmosphere Living Soils Vegetation Methane Hydrates 830 1500-2400 Carbon 450 - 650 1700-2500 Inventory Fossil Fuel Reserves Hydrocarbons (GtC) 1000 - 2000 Marine Carbonate Calcium Carbonate Upper Ocean Sediments Shells 900 1700-2500 Deep Ocean 38,000 3/9/21 Climate Change 6 28 Deep Ocean Permafrost & Atmosphere Living Soils Vegetation Methane Hydrates 830 1500-2400 “Surface” 450 - 650 1700-2500 Fossil Fuel Reserves Carbon 1000 - 2000 Marine Carbonate Upper Ocean Sediments Inventory 900 1700-2500 (GtC) Deep Ocean 38,000 3/9/21 Climate Change 6 30 Permafrost & Atmosphere Living Soils Vegetation Methane Hydrates 830 1500-2400 Total 450 - 650 1700-2500 Fossil Fuel Reserves Carbon 1000 - 2000 Marine Carbonate Upper Ocean Sediments Inventory 900 1700-2500 (GtC) Deep Ocean 38,000 Carbon in Rocks 50,000,000 3/9/21 Climate Change 6 31 Carbon in Limestone Rock (CaCO3) 40,000,000 Carbon in Shale Rock 10,000,000 Permafrost & Atmosphere Living Soils Vegetation Methane Hydrates 830 1500-2400 Total 450 - 650 1700-2500 Fossil Fuel Reserves Carbon 1000 - 2000 Marine Carbonate Upper Ocean Sediments Inventory 900 1700-2500 (GtC) Deep Ocean 38,000 3/9/21 Climate Change 6 32 Carbon in Limestone Rock (CaCO3) 40,000,000 Carbon in Shale Rock 10,000,000 Atmosphere Living Vegetation 830 450 - 650 Permafrost & Atmosphere Living Soils Vegetation Methane Hydrates 830 1500-2400 450 - 650 1700-2500 Total Fossil Fuel Reserves 1000 - 2000Fossil Fuel Reserves Carbon 1000 - 2000 Marine Carbonate Upper Ocean Sediments Inventory 900 1700-2500 (GtC) Deep Ocean 38,000 3/9/21 Climate Change 6 33 Carbon in Limestone Rock (CaCO3) 40,000,000 Carbon in Shale Rock 10,000,000 If All those 50 Million Gigatons of Carbon were put into the Atmosphere as CO2 • CO2 would increase 60,000 fold • Air would contain 37 atmospheres of CO2 • That’s just 40% of Venus CO2 , but enough to cook the surface to many hundreds of F 3/9/21 Climate Change 6 34 What Happens When a CO2 Molecule Wanders into a Drop of Water? It may just dissolve in the water and float around or It may react with the water 3/9/21 Climate Change 6 35 A CO2 Molecule and an H2O can join up to form Carbonic Acid O H Carbonic Acid O H O C + O → H C H O O H2CO3 3/9/21 Climate Change 6 37 A CO2 Molecule and an H2O can join up to form Carbonic Acid O H Carbonic Acid O H O C + O → H C H O O H2CO3 … which can dissociate under the right Dissociate conditions to form a Bi-Carbonate ion + a Hydrogen ion… H - H+ - Hydrogen Ion HCO3 Bi-Carbonate Ion 3/9/21 Climate Change 6 38 A CO2 Molecule and an H2O can join up to form Carbonic Acid O H Carbonic Acid O H O C + O → H C H O O H2CO3 … and can further dissociate into a Carbonate ion Dissociate H+ - + H+ H H = CO3 Hydrogen Ions - Hydrogen Ion HCO3 Carbonate Ion Bi-Carbonate Ion 3/9/21 Climate Change 6 39 A CO2 Molecule and an H2O can join up to form Carbonic Acid O H Carbonic Acid O H O C + O → H C H O O … which is what sea H2CO3 animals need to Ca2+ make shells… Dissociate H+ - + H+ H H = CO3 Hydrogen Ions - Hydrogen Ion HCO3 Carbonate Ion Bi-Carbonate Ion 3/9/21 Climate Change 6 40 A CO2 Molecule and an H2O can join up to form Carbonic Acid O H Carbonic Acid O H O C + O → H C H O O H2CO3 Dissociate H+ - + H+ H H = CO3 Hydrogen Ions - Hydrogen Ion HCO3 Carbonate Ion Bi-Carbonate Ion 3/9/21 Climate Change 6 42 The Form CO2 Takes in Water Depends on pH O Bi- Carbonic Acid H& CarbonicH Carbonate O Acid Carbonate O C + O → H C H O O Rain