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Teaching Climate Change

Teaching Climate Change. Cosmos Special Interest Group. Aileen O’Donoghue. Priest Associate Professor of Physics St. Lawrence University, Canton, NY. Emphases for Students. Earth Will Be FINE! it’s been much hotter and much colder

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Teaching Climate Change

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  1. Teaching Climate Change Cosmos Special Interest Group Aileen O’Donoghue Priest Associate Professor of Physics St. Lawrence University, Canton, NY

  2. Emphases for Students • Earth Will Be FINE! • it’s been much hotter and much colder • the 6.8 billion people won’t be fine • nor will the polar bears, pikas, and other megafauna • What we know: Data & Theories • Data carefully collected & analyzed for decades • North America Student/Class semester project • Students collect on-line data for a city all semester • How we know it: Process of science • peer review: trying to insure honesty, not orthodoxy • Climate Models & Predictions • IPCC Fourth Assessment Report • Climate Symposium Project

  3. North America Project • Seasonal Study of N. Am. Cities • Each student has a city • Download data from weather.gov each day • only 24 hours of data on line • Enter data into spreadsheets (provided) • produces plots of weather data • Friday weather analysis • I download 4 weather maps/day for Power Point • Gather in regional groups to discuss weather • compare plots to maps … eg. Fronts moving through • Discuss national weather as a class • At end, compare data to national trends

  4. Climate Monitoring National Climatic Data Center http://www.ncdc.noaa.gov/ climate-monitoring/

  5. Temperatures cool SE, Warm north, hot Maine! Precipitation wet SW & SE, dry E & W bands in north US National Overviews http://www.ncdc.noaa.gov/oa/climate/research/2010/mar/yeartodate.html also: http://www.esrl.noaa.gov/psd/enso/enso.currclim.html

  6. US National Anomalies Cool southeast, cold FL Warm NW and NE (Maine!)

  7. US National Anomalies Wet southwest, FL, East Coast, Middle Dry northern mountain west, great lakes

  8. Global Climate Course Topics • Geography • physical features of Earth • Basic Meteorology • air pressure, winds, global circulation, fronts • Climate History & Variations • instrumental & proxy records • Atmospheric Variations (ENSO, etc) • External (Milankovitch, Solar, Galactic) • Climate Modeling & the Future • IPCC, UCC, the “skeptics”

  9. What do we know • Past climates • how do we know of past climates? • Variations in climate • how does climate vary naturally? • Predicting the future • how do we model inputs & feedbacks? • IPCC • UCC • Skeptics

  10. Past Climate Records Northern Winter: CO2 builds up from decay. Northern Summer: Plants absorb CO2 • Instrumental • 18th – 21st centuries with increasing accuracy • Best in Europe, N. America, Australia • Very little data over oceans, 70% of surface • Keeling Curve: 1957 - present • CO2 in air over Mauna Loa, Hawaii

  11. Past Climate Records • Proxy (indirect natural) Records • Tree rings • Temperature, precipitation, fire, insects, etc. • Depends on area, species level of stress • best near stress limit • Back to ~1000 years (bristlecone pine in CA) • plus overlapping with structures

  12. Past Climates shrub birch spruce oak Pine • Proxy (indirect natural) Records • Palynology (pollen) from sediments • Accumulated in peat bogs & lakes • Must be independently dated (cross-matched or 12C) • Local influences complicate records • eg. Fire, flood, etc. • Types of pollen vary in uniqueness • eg. Pine pollen everywhere … even ice caps! sedge

  13. Past Climates • Vostok, Antarctica & Greenland Ice Cores Greenland Ice Core Summers indicated by arrows.

  14. Past Climates • Vostok, Antarctica & Greenland Ice Cores • Show annual* variations of atmosphere • Bubbles of air contain old atmosphere • Variations in CO2, CH4 Give • Comparisons to today, • Correlations with temperature • Ice crystals vary in composition • Different Isotopes of Oxygen, Hydrogen, etc. • Dust • Volcanos, Impacts, Winds, Organic Matter *Where annual layers unclear, chronology is reconstructed from other annual variables

  15. Isotopes • Number of neutrons in nuclei varies • eg. Oxygen 16 (16O) & 18 (18O) • 18O heavier than 16O  harder to evaporate • Ice Cores • High ratio of 18O/16O for warm globe • Deep Sea Sediments • High ratio of 18O/16O for cool globe 18O 16O 8 protons 10 neutrons 8 protons 8 neutrons On average: 1 18O for 1000 16O

  16. Isotopes 2H/1H • Variations indicate temperature • Higher 18O/16O in ice  warmer • Lower 18O/16O in ice  cooler 18O/16O Arctic & Antarctic show same variations  variations are global

  17. Isotopes • Sea Temp. • Higher 18O/16O  cooler • Lower 18O/16O  warmer Sea surface temperature 18O/16O C. R. W. Ellison et al., Science 312, 1929 -1932 (2006)

  18. Isotopes 2H/1H 2H/1H • Variations track with GH gases Methane Carbon Dioxide now then www.realclimate.org/index.php?p=221

  19. Temperature & GH Gases Temperature tracks with gases … Which drives which? Carbon Dioxide Temp (°C) Methane now then Ice Core Contributions to Global Change Research: Past Successes and Future Directions National Ice Core Laboratory Ice Core Working Group, May, 1998.

  20. Global CO2 • CO2 from Ice Cores & Mauna Loa

  21. Climate Variations • Due to • Atmospheric variations • Pacific Cycles • El Niño Soutern Oscillation (ENSO) • Pacific Decadal Oscillation • Atlantic Cycles • North Atlantic Oscillation • Atlantic Multidecadal Oscillation

  22. Variations in the Atmosphere • NAO Negative Phase mid 1950’s - 1970 It WAS colder when we were kids!

  23. Variations in the Atmosphere • NAO Mostly positive since mid-70’s Skeptics use cooling of eastern Canada to dispute global warming

  24. Variations in the Atmosphere • Atlantic Multidecadal Oscillation (AMO) • Sea Surface Temperature in North Atlantic

  25. Variations in the Atmosphere • AMO • Correlates with numbers of major hurricanes … and southwestern droughts! Not perfect correlation … what else is going on?

  26. Variations in the Atmosphere • Drought • Correlation with PDO and AMO Droughts more severe & widespread when AMO is positive Current Conditions oceanword.tamu. edu

  27. Variations in the Atmosphere • Insolation Variations • Solar brightness variations • sunspots & other stellar variations • Earth orbital variations (Milankovitch) • other planets’ gravity vary Earth’s orbit • Solar system environmental variation • Sun moves through galactic environment

  28. Insolation 9,000 years ago, ice age ended! Some argue this is the cause of ALL climate change … so we can ignore our CO2 • Varies with Milankovitch Cycles • Last million years for 65 N (Berger (1991)) Now Then

  29. Milankovitch and Temperatures Vostok Core Data Temperature from 18O/16O Milankovitch Insolation Now Then Time Connection apparent … but can it explain current warming?

  30. Modeling the Climate • Climate Systems • Sun – source of (almost) all energy • Atmosphere – changes over hours • Oceans – surface changes over weeks – depths change over millennia • Biosphere – changes annually to centuries • Cryosphere – ice, glaciers permafrost, snow – various change scales • Geosphere – volcanos, continental drif – long time scales, large changes

  31. Modeling the Climate • Systems & Feedbacks Among • Radiation, Surface and Atmosphere (CO2) • insolation (incoming sunlight varies) • reflection, absorption, re-radiation by surface, air • Water cycle • evaporation, precipitation, runoff • Land surface • soil moisture, vegetation, topography, snow & ice • Ocean • surface currents, deep currents, chemistry (salinity) • Sea Ice • strongly affected by feedbacks

  32. Carbon Dioxide • Long-term sources: Volcanoes & Humans • Long-term sinks: Chemical Weathering • H2O + CO2 H2CO3 H+ + HCO3 • CaCO3 + H+ Ca + HCO3 • Variable storage: Biosphere • plants absorb CO2 to grow • trees make wood out of air! • plants make us … we’re made of air! • decay releases CO2 Carbonic Acid Bicarbonate can combine with many compounds eg. NaHCO3, Ca(HCO3)2

  33. Feedbacks • Greenhouse Effect: Warming • Good … makes Earth inhabitable!! • Ground absorbs sunlight Ground heats (parking lots in summer) Ground radiates heat (Infrared, IR) Atmosphere absorbs (some) IR Atmosphere heats I spend lots of time on the Earth’s energy budget: short wave, long wave, albedo, absorption, latent heat, sensible heat

  34. Greenhouse Effect Concept Inventory • Dr. John Keller, Cal Poly: Poster C24 • Misconceptions about Climate Change • Greenhouse = Warming = Ozone Hole • Extra energy entering atmosphere (UV) • “trapped” in atmosphere • Climate Concept Invantory (handout) Extra heat from the Sun (UV) Ozone Hole

  35. Feedbacks • Feedback Mechanism: Evaporation • Clouds shade surface, cool it, warming stops? • H2O vapor absorbs more IR, more warming Runaway Greenhouse … Venus! • Feedback Mechanism: Plant Growth • More CO2 increases plant growth • More plant growth is good!! • Plants absorb CO2(Keeling curve annual cycles) CO2 is Reduced BUT … why isn’t it working yet? www.co2science.org

  36. Feedbacks • Feedback Mechanism: Ice-Albedo Effect • Warming melts glaciers, sea ice • Ground warms more than snow/ice Ground warms, radiates more IR Atmosphere warms More ice melts

  37. IPCC • Intergovernmental Panel on Climate Change • Established in 1988 • World Meteorological Org. (WMO) • UN Environment Programme (UNEP) • Mandate “The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.” http://www.ipcc.ch/about/about.htm

  38. IPCC • Intergovernmental Panel on Climate Change “The IPCC does not carry out research nor does it monitor climate related data or other relevant parameters. It bases its assessment mainly on peer reviewed and published scientific/technical literature. Its role, organisation, participation and general procedures are laid down in the ‘Principles Governing IPCC Work’“ Opportunity to discuss process of science & peer review. http://www.ipcc.ch/about/about.htm

  39. IPCC • Working Groups • I: Science • knowns, unknowns & projections • II: Impact and Adaption • vulnerability: natural and human • consequences: + and – • III: Mitigation • options for changing human behavior and impact • Task Force on National Greenhouse Gas Inventories

  40. IPCC ARF WGI • Components of Climate Change Accounts for natural processes eg. Changes in evaporation eg. Melting permafrost releasing methane

  41. IPCC ARF WGI • Radiative Forcing 1750 - 2005 “Ozone Layer” absorbs UV, reduces RF at tropopause Carbon Dioxide Methane Buildings increase surface albedo relative to forests Aerosols (particles) reflect sunlight AND increase cloud cover (eg. Contrails) Solar radiation has increased since 1750 (Little Ice Age end)

  42. IPCC ARF • Continued Warming What we’re committed to by past behavior!

  43. IPCC ARF • Effects of Changing Mean Does not mean it never gets cold!

  44. Union of Concerned Scientitsts • Confronting Climate Change in the U.S. Northeast: Science, Impacts and Solutions http://www.ucsusa.org/global_warming/

  45. UCC Northeast US • Climate of New York State

  46. The Skeptics • Important voices! • Skeptics keep science honest • Agreements • CO2 in atmosphere is increasing rapidly • CO2 levels correlate with temperature • Arguments • Climate is driven exclusively by insolation • Milankovitch Cycles • Sunspot Cycles • Too expensive to reduce CO2: Adapt • Global warming is good!

  47. Climate Syposium • Climate Change Impacts • Each pair has a world city • chosen from a list I provide • Two Power Point presentations • Geography & current climate • mostly using web resources • Possible impacts of climate change • IPCC Regional Impacts • Union of Concerned Scientists Regional Impacts • Sea Level Rise maps • CReSIS (Center for Remote Sensing of Ice Sheets) • U Az Geosciences Environmental Studies Lab

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