Teaching Climate ChangeTeaching Climate ChangeEPO Special Interest GroupEPO Special Interest Group

Aileen O’DonoghueAileen O’DonoghuePriest Associate Professor of Physics

St. Lawrence University, Canton, NYPriest Associate Professor of Physics

St. Lawrence University, Canton, NY

Emphases for the PublicEmphases 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 knowWhat 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 RecordsPast Climate Records 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

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

Northern Summer: Plants absorb CO2

Northern Winter: CO2 builds up from decay.

Past Climate RecordsPast 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 ClimatesPast Climates 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!

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!birchbirch

sprucespruce

shrubshrub

PinePinesedgesedge

oakoak

Past ClimatesPast Climates Vostok, Antarctica & Greenland Ice

Cores Vostok, Antarctica & Greenland Ice

CoresGreenland Ice Core Summers indicated by

arrows.

Greenland Ice Core Summers indicated by

arrows.

Past ClimatesPast 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

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*Where annual layers unclear, chronology is reconstructed from other annual variables

IsotopesIsotopes 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

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

18O18O16O16O8 protons

8 neutrons

8 protons 8

neutrons

8 protons 10

neutrons

8 protons 10

neutronsOn average: 1 18O for 1000

16O

On average: 1 18O for 1000

16O

IsotopesIsotopes Variations indicate temperature

Higher 18O/16O in ice warmer Lower 18O/16O in ice cooler

Variations indicate temperature Higher 18O/16O in ice warmer Lower 18O/16O in ice cooler

2H/1H2H/1H

18O/16O18O/16O

Arctic & Antarctic show same variations

variations are global

Arctic & Antarctic show same variations

variations are global

Sea Temp. Higher 18O/16O

cooler Lower 18O/16O

warmer

Sea Temp. Higher 18O/16O

cooler Lower 18O/16O

warmer

C. R. W. Ellison et al., Science 312, 1929 -1932

(2006)

C. R. W. Ellison et al., Science 312, 1929 -1932

(2006)

Sea surface temperatureSea surface temperature

18O/16O18O/16O

IsotopesIsotopes

IsotopesIsotopes Variations track

with GH gases Variations track

with GH gases

2H/1H2H/1H

2H/1H2H/1H

Methane

Carbon Dioxide

www.realclimate.org/index.php?p=221

now then

Temperature & GH GasesTemperature & GH Gases

Ice Core Contributions to Global Change Research: Past Successes and Future Directions

National Ice Core Laboratory Ice Core Working Group, May, 1998.

Carbon Dioxide

Methane

Temp (°C)

Temperature tracks with

gases …

Which drives which?

Temperature tracks with

gases …

Which drives which?

now then

Global CO2Global CO2

CO2 from Ice Cores & Mauna Loa

CO2 from Ice Cores & Mauna Loa

IsotopesIsotopes 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?

Discussion: How much should we simplify?

Modeling the ClimateModeling 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 ClimateModeling 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

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

Carbon DioxideCarbon 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

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 AcidCarbonic Acid Bicarbonate can combine with many compounds eg.

NaHCO3, Ca(HCO3)2

Bicarbonate can combine with many compounds eg.

NaHCO3, Ca(HCO3)2

FeedbacksFeedbacks 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

Greenhouse Effect Concept Inventory

Dr. John Keller, Cal Poly Poster C24

Dr. John Keller, Cal Poly Poster C24

FeedbacksFeedbacks 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?

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

FeedbacksFeedbacks 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

H2O 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

H2O vapor absorbs more IR, more warming “Hot House Earth”

Climate VariationsClimate 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 AtmosphereVariations in the Atmosphere NAO Negative Phase mid 1950’s - 1970 NAO Negative Phase mid 1950’s - 1970

It WAS colder

when we were kids!

It WAS colder

when we were kids!

Variations in the AtmosphereVariations in the Atmosphere NAO Mostly positive since mid-70’s NAO Mostly positive since mid-70’s

Skeptics use

cooling of eastern

Canada to dispute global

warming

Variations in the AtmosphereVariations 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 AtmosphereVariations 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 AtmosphereVariations in the Atmosphere

Droughts more severe

& widespread

when AMO is positive

Droughts more severe

& widespread

when AMO is positive

oceanword.tamu. edu

Current Conditions

Current Conditions

Variations in the AtmosphereVariations 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

InsolationInsolation 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!9,000 years ago, ice age ended!

Some argue this is the cause of ALL climate change … so we can ignore our

CO2

Some argue this is the cause of ALL climate change … so we can ignore our

CO2

Milankovitch and TemperaturesMilankovitch and Temperatures

Vostok Core DataVostok Core Data

Milankovitch InsolationMilankovitch Insolation

Temperature from 18O/16OTemperature from 18O/16O

Connection apparent … but can it explain current

warming?

Connection apparent … but can it explain current

warming?

IPCCIPCC 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.”

“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

IPCCIPCC Intergovernmental Panel on Climate

Change 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’“

“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’“

http://www.ipcc.ch/about/about.htm

IPCCIPCC 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 NationalGreenhouse 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 NationalGreenhouse Gas Inventories

IPCCIPCC 4th Assessment

Released 2007 WGI = 701 pages!

available on lineipcc-wg1.ucar.edu/wg1

available in printCambridge U. Press

4th Assessment Released 2007 WGI = 701 pages!

available on lineipcc-wg1.ucar.edu/wg1

available in printCambridge U. Press

IPCCIPCC 4th Assessment

Released 2007 WGI = 701 pages!

available on lineipcc-wg1.ucar.edu/wg1

available in printCambridge U. Press

4th Assessment Released 2007 WGI = 701 pages!

available on lineipcc-wg1.ucar.edu/wg1

available in printCambridge U. Press

IPCC ARF WGIIPCC ARF WGI Components of Climate Change Components of Climate Change

Accounts for natural processesAccounts for natural processes

eg. Changes in evaporation

eg. Changes in evaporation

eg. Melting permafrost releasing methane

eg. Melting permafrost releasing methane

IPCC Climate DriversIPCC Climate Drivers Greenhouse Gases: CO2, CH4, H2O, NOx Greenhouse Gases: CO2, CH4, H2O, NOx

Grey Bars = Natural Variabilit

y

Grey Bars = Natural Variabilit

y

Com-bined rate of chang

e

Com-bined rate of chang

e

Radiative forcing is a change in the radiation

balance at the top of the atmosphere. Positive increases warming.

IPCC ARF WGIIPCC ARF WGI Radiative Forcing 1750 - 2005 Radiative Forcing 1750 - 2005

Carbon DioxideCarbon Dioxide

“Ozone Layer” absorbs UV, reduces

RF at tropopause

“Ozone Layer” absorbs UV, reduces

RF at tropopauseMethaneMethane

Buildings increase surface albedo

relative to forests

Buildings increase surface albedo

relative to forests

Aerosols (particles) reflect sunlight AND increase cloud cover

(eg. Contrails)

Aerosols (particles) reflect sunlight AND increase cloud cover

(eg. Contrails)

Solar radiation has increased since

1750 (Little Ice Age end)

Solar radiation has increased since

1750 (Little Ice Age end)

IPCC ScenariosIPCC 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 ARFIPCC ARF Continued Warming Continued Warming

What we’re committed to by past

behavior!

What we’re committed to by past

behavior!

Union of Concerned ScientitstsUnion of Concerned Scientitsts Confronting Climate Change in the U.S.

Northeast: Science, Impacts and Solutions

Confronting Climate Change in the U.S. Northeast: Science, Impacts and Solutions

http://www.ucsusa.org/global_warming/

UCC Northeast USUCC Northeast US Climate of New York State Climate of New York State

IPCC ARFIPCC ARF Effects of Changing Mean Effects of Changing Mean

Does not mean it

never gets cold!

Does not mean it

never gets cold!

The SkepticsThe 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!

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!

DiscussionDiscussion 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?