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

Emphases for the Public 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  Not NEW!  “amplified warming” since 1850 (John Tyndall)  Data carefully collected & analyzed for decades  requires careful study  understanding before dismissal! How we know it: Process of science  peer review: trying to insure honesty, not orthodoxy 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  Not NEW!  “amplified warming” since 1850 (John Tyndall)  Data carefully collected & analyzed for decades  requires careful study  understanding before dismissal! How we know it: Process of science  peer review: trying to insure honesty, not orthodoxy

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 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

Past Climate Records Instrumental  18 th – 21 st centuries with increasing accuracy  Best in Europe, N. America, Australia  Very little data over oceans, 70% of surface  Keeling Curve: present  CO 2 in air over Mauna Loa, Hawaii Instrumental  18 th – 21 st centuries with increasing accuracy  Best in Europe, N. America, Australia  Very little data over oceans, 70% of surface  Keeling Curve: present  CO 2 in air over Mauna Loa, Hawaii Northern Summer: Plants absorb CO 2 Northern Winter: CO 2 builds up from decay.

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 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

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

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

Past Climates Vostok, Antarctica & Greenland Ice Cores  Show annual* variations of atmosphere  Bubbles of air contain old atmosphere  Variations in CO 2, CH 4 Give  Comparisons to today,  Correlations with temperature  Ice crystals vary in composition  Different Isotopes of Oxygen, Hydrogen, etc.  Dust  Volcanos, Impacts, Winds, Organic Matter Vostok, Antarctica & Greenland Ice Cores  Show annual* variations of atmosphere  Bubbles of air contain old atmosphere  Variations in CO 2, CH 4 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

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

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

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

Variations track with GH gases 2 H/ 1 H Methane Carbon Dioxide nowthen

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

Global CO 2 CO 2 from Ice Cores & Mauna Loa

Isotopes Necessary to understand ice core data!  Allows reconstruction of temperature  Only way to get to last curve! Respects the audience  Demands they respect the science Necessary to understand ice core data!  Allows reconstruction of temperature  Only way to get to last curve! Respects the audience  Demands they respect the science Discussion: How much should we simplify?

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 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

Modeling the Climate Systems & Feedbacks Among  Radiation, Surface and Atmosphere (CO 2 )  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 Systems & Feedbacks Among  Radiation, Surface and Atmosphere (CO 2 )  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

Carbon Dioxide Long-term sources: Volcanoes & Humans Long-term sinks: Chemical Weathering  H 2 O + CO 2  H 2 CO 3  H + + HCO 3  CaCO 3 + H +  Ca + HCO 3 Variable storage: Biosphere  plants absorb CO 2 to grow  trees make wood out of air!  plants make us … we’re made of air!  decay releases CO 2 Long-term sources: Volcanoes & Humans Long-term sinks: Chemical Weathering  H 2 O + CO 2  H 2 CO 3  H + + HCO 3  CaCO 3 + H +  Ca + HCO 3 Variable storage: Biosphere  plants absorb CO 2 to grow  trees make wood out of air!  plants make us … we’re made of air!  decay releases CO 2 Carbonic Acid Bicarbonate can combine with many compounds eg. NaHCO 3, Ca(HCO 3 ) 2

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 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

Greenhouse Effect Concept Inventory Dr. John Keller, Cal Poly  Poster C24 Dr. John Keller, Cal Poly  Poster C24

Feedbacks Feedback Mechanism: Evaporation  Clouds shade surface, cool it, warming stops?  H 2 O vapor absorbs more IR, more warming Runaway Greenhouse … Venus! Feedback Mechanism: Plant Growth  More CO 2 increases plant growth  More plant growth is good!!  Plants absorb CO 2 (Keeling curve annual cycles) CO 2 is Reduced BUT … why isn’t it working yet? Feedback Mechanism: Evaporation  Clouds shade surface, cool it, warming stops?  H 2 O vapor absorbs more IR, more warming Runaway Greenhouse … Venus! Feedback Mechanism: Plant Growth  More CO 2 increases plant growth  More plant growth is good!!  Plants absorb CO 2 (Keeling curve annual cycles) CO 2 is Reduced BUT … why isn’t it working yet?

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 Feedback Mechanism: Evaporation  More clouds & cooling, snow comes back  Warming halted  H 2 O vapor absorbs more IR, more warming  “Hot House Earth” 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 Feedback Mechanism: Evaporation  More clouds & cooling, snow comes back  Warming halted  H 2 O vapor absorbs more IR, more warming  “Hot House Earth”

Climate Variations Due to  Atmospheric variations  Pacific Cycles  El Niño Soutern Oscillation (ENSO)  Pacific Decadal Oscillation  Atlantic Cycles  North Atlantic Oscillation  Atlantic Multidecadal Oscillation Due to  Atmospheric variations  Pacific Cycles  El Niño Soutern Oscillation (ENSO)  Pacific Decadal Oscillation  Atlantic Cycles  North Atlantic Oscillation  Atlantic Multidecadal Oscillation

Variations in the Atmosphere NAO Negative Phase mid 1950’s It WAS colder when we were kids!

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

Variations in the Atmosphere Atlantic Multidecadal Oscillation (AMO)  Sea Surface Temperature in North Atlantic Atlantic Multidecadal Oscillation (AMO)  Sea Surface Temperature in North Atlantic

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

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

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 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

Insolation Varies with Milankovitch Cycles  Last million years for 65 N ( Berger (1991) ) Varies with Milankovitch Cycles  Last million years for 65 N ( Berger (1991) ) 9,000 years ago, ice age ended! Some argue this is the cause of ALL climate change … so we can ignore our CO 2

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

IPCC Intergovernmental Panel on Climate Change  Established in 1988  World Meteorological Org. (WMO)  UN Environment Programme (UNEP)  Mandate 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.”

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’“

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 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

IPCC 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press

IPCC 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press 4 th Assessment  Released 2007  WGI = 701 pages!  available on line ipcc-wg1.ucar.edu/wg1  available in print Cambridge U. Press

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

IPCC Climate Drivers Greenhouse Gases: CO 2, CH 4, H 2 O, NO x Grey Bars = Natural Variability Com- bined rate of change Radiative forcing is a change in the radiation balance at the top of the atmosphere. Positive increases warming.

IPCC ARF WGI Radiative Forcing Carbon Dioxide “Ozone Layer” absorbs UV, reduces RF at tropopause 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)

IPCC Scenarios A1B  Very rapid economic growth  Global population peaks mid-century then declines  rapid introduction of new, more efficient technologies. A2  Very heterogeneous world  Continuously increasing global population  Regionally oriented economic growth more fragmented and slower than in other storylines. B2  Same global population as in the A1  rapid changes toward a service and information economy  reductions in material intensity  introduction of clean, green technologies. A1B  Very rapid economic growth  Global population peaks mid-century then declines  rapid introduction of new, more efficient technologies. A2  Very heterogeneous world  Continuously increasing global population  Regionally oriented economic growth more fragmented and slower than in other storylines. B2  Same global population as in the A1  rapid changes toward a service and information economy  reductions in material intensity  introduction of clean, green technologies.

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

Union of Concerned Scientitsts Confronting Climate Change in the U.S. Northeast: Science, Impacts and Solutions

UCC Northeast US Climate of New York State

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

The Skeptics Important voices!  Skeptics keep science honest Agreements  CO 2 in atmosphere is increasing rapidly  CO 2 levels correlate with temperature Arguments  Climate is driven exclusively by insolation  Milankovitch Cycles  Sunspot Cycles  Too expensive to reduce CO 2 : Adapt  Global warming is good! Important voices!  Skeptics keep science honest Agreements  CO 2 in atmosphere is increasing rapidly  CO 2 levels correlate with temperature Arguments  Climate is driven exclusively by insolation  Milankovitch Cycles  Sunspot Cycles  Too expensive to reduce CO 2 : Adapt  Global warming is good!

Discussion What should we include & leave out?  How much complexity to include? Should we confront politics directly? How do we handle hostility? What should we include & leave out?  How much complexity to include? Should we confront politics directly? How do we handle hostility?