Global Climate ChangeGlobal Climate Change

Questions of the day:Questions of the day:

o 1. What is the greenhouse effect? Is it 1. What is the greenhouse effect? Is it natural or human caused?natural or human caused?

o 2. Did ozone depletion cause g.c.c?2. Did ozone depletion cause g.c.c?o 3. Are humans influencing g.c.c?3. Are humans influencing g.c.c?o 4. What are some of the potential 4. What are some of the potential

effects of g.c.c?effects of g.c.c?

Greenhouse EffectGreenhouse Effect

Overview of Chapter 20Overview of Chapter 20

o Introduction to Climate ChangeIntroduction to Climate Change• Causes of Global Climate ChangeCauses of Global Climate Change

o Effects of Climate ChangeEffects of Climate Change• Melting Ice and Rising Sea LevelMelting Ice and Rising Sea Level• Changes in Precipitation PatternsChanges in Precipitation Patterns• Effects on OrganismsEffects on Organisms• Effects on Human HealthEffects on Human Health• Effects on AgricultureEffects on Agriculture

o Dealing with Global Climate ChangeDealing with Global Climate Change

Hot: Living through the next Hot: Living through the next 50years on Earth 50years on Earth

Mark HertsgaardMark Hertsgaardo http://www.theworld.org/2011/03/mark-

hertsgaard-fatherhood-and-climate-change/#

Is it happening?Is it happening?

o ‘‘97, 98, ’01 Three warmest on record, 97, 98, ’01 Three warmest on record, spring earlier, fall later than normal spring earlier, fall later than normal season changesseason changes

o IPCC- International panel on climate IPCC- International panel on climate change in 1995, concluded human-change in 1995, concluded human-induced air pollution DOES have an induced air pollution DOES have an impact.impact.

o Prediction 2-6 degree F increase in 21Prediction 2-6 degree F increase in 21stst century, not uniform heating across century, not uniform heating across globeglobe

Introduction to Climate Change-Introduction to Climate Change-Mean Annual Global Temperature 1960-Mean Annual Global Temperature 1960-

20052005

Climate Change TerminologyClimate Change Terminology

o Greenhouse GasGreenhouse Gas• Gas that absorbs infrared radiationGas that absorbs infrared radiation• Ex: Carbon dioxide, methane, nitrous oxide, Ex: Carbon dioxide, methane, nitrous oxide,

chlorofluorocarbons, tropospheric ozone, water chlorofluorocarbons, tropospheric ozone, water vapourvapour

o Positive FeedbackPositive Feedback• Change in some condition triggers a response that Change in some condition triggers a response that

intensifies the changed condition intensifies the changed condition o Infrared RadiationInfrared Radiation

• Radiation that has a wavelength that is longer than Radiation that has a wavelength that is longer than that of visible light, but shorter than that of radio that of visible light, but shorter than that of radio waves waves

o Greenhouse EffectGreenhouse Effect• Increase of heat in a system where energy enters Increase of heat in a system where energy enters

(often as light), is absorbed as heat, and released (often as light), is absorbed as heat, and released sometime later sometime later

Greenhouse gasesGreenhouse gaseso CO2- fossil fuel burning, deforestation, CO2- fossil fuel burning, deforestation,

tree burningtree burningo CH4- methane-unburned gas, anaerobic CH4- methane-unburned gas, anaerobic

activity in landfills, intestines of cattle and activity in landfills, intestines of cattle and manman

o Nox- nitrogen oxides, from burning and Nox- nitrogen oxides, from burning and troposphere O3troposphere O3

o CFC’s- trap heat and cause ozone CFC’s- trap heat and cause ozone depletiondepletion

o Aerosols and suspended particles- actually Aerosols and suspended particles- actually cool atmosphere, cool atmosphere,

Introduction to Climate ChangeIntroduction to Climate Change

o Evidence for Climate ChangeEvidence for Climate Change• 11 of the 12 years between 1995 and 2006 11 of the 12 years between 1995 and 2006

were among the twelve warmest years were among the twelve warmest years since the mid-1800s since the mid-1800s

• Phenological spring in N. hemisphere now Phenological spring in N. hemisphere now comes 6 days earliercomes 6 days earlier

o Warming is not due to natural causesWarming is not due to natural causes• Human produced greenhouse gases are Human produced greenhouse gases are

most plausible explanationmost plausible explanation

Causes of Climate ChangeCauses of Climate Change

o Greenhouse gas concentrations Greenhouse gas concentrations increasingincreasing

Causes of Climate ChangeCauses of Climate Change

o Increased Increased concentration of concentration of COCO22 (right) (right)• Burning fossil fuels Burning fossil fuels

in cars, industry in cars, industry and homesand homes

• DeforestationDeforestation• Burning of forestsBurning of forests

Other Pollutants Cool the Other Pollutants Cool the AtmosphereAtmosphere

o Atmospheric Aerosols tend to cool the Atmospheric Aerosols tend to cool the atmosphereatmosphere• Both human and natural sourcesBoth human and natural sources• Tiny particles that remain in troposphere Tiny particles that remain in troposphere

for weeks or monthsfor weeks or months• Contain many chemicals, but often contain Contain many chemicals, but often contain

sulfursulfur

o Complicates models of climate changeComplicates models of climate change

Climate ModelsClimate Models

o Climate affected by:Climate affected by:• winds, clouds, ocean currents, and albedo winds, clouds, ocean currents, and albedo

o Used to explore past climate eventsUsed to explore past climate eventso Advanced models can project future Advanced models can project future

warming eventswarming eventso Models are only as good as the data Models are only as good as the data

and law used to program themand law used to program them• They have limitationsThey have limitations

Climate ModelsClimate Models

Effects of Global Climate ChangeEffects of Global Climate Changeo Ocean as COOcean as CO22 sink - excess CO sink - excess CO22 is starting to is starting to

harm ocean lifeharm ocean life

Effects of Global Climate Change- Effects of Global Climate Change- Melting Ice and Rising Sea LevelsMelting Ice and Rising Sea Levels

o Sea level rise caused in 2 waysSea level rise caused in 2 ways• Thermal ExpansionThermal Expansion

• Water expands as it warmsWater expands as it warms• Melting of land iceMelting of land ice

• Retreat of glacier and thinning of ice at the polesRetreat of glacier and thinning of ice at the poles

o Melting has positive feedbackMelting has positive feedback• Increased melting decreases ice, which Increased melting decreases ice, which

decreases albedo leading to further decreases albedo leading to further warmingwarming

Melting Ice and Rising Sea Melting Ice and Rising Sea LevelsLevels

19519577

19919988

Philadelphia with rising sea Philadelphia with rising sea levelslevels

o http://www.pbs.org/wgbh/warming/

Case-In-Point Impacts in Fragile Case-In-Point Impacts in Fragile AreasAreas

o Eskimo Inuit live Eskimo Inuit live traditional life dictated traditional life dictated by freezing climateby freezing climate

o Climate change is Climate change is altering their existencealtering their existence• Wildlife are smaller or Wildlife are smaller or

displaceddisplaced• Reduced snow cover and Reduced snow cover and

shorter river ice seasonsshorter river ice seasons• Thawing of permafrost Thawing of permafrost

(right)(right)

Effects/Mitigation/AdaptationEffects/Mitigation/Adaptation

o Group postersGroup posters

o Some areas will get more water, some Some areas will get more water, some areas will have greater droughtsareas will have greater droughts• Ex: Hurricanes will likely get strongerEx: Hurricanes will likely get stronger

Effects of Global Climate Change- Effects of Global Climate Change- Changing Precipitation PatternsChanging Precipitation Patterns

o Zooplankton in parts of California Current Zooplankton in parts of California Current have decreased by 80% since 1951have decreased by 80% since 1951• Effecting entire food chainEffecting entire food chain

o Decline in krill around AntarcticaDecline in krill around Antarctica• Caused decrease in penguin populationsCaused decrease in penguin populations

o Species have shifted their geographic Species have shifted their geographic rangerange

o Migrating birds are returning to summer Migrating birds are returning to summer homes earlierhomes earlier• Food is not available at this timeFood is not available at this time

Effects of Global Climate Change- Effects of Global Climate Change- Effects on OrganismsEffects on Organisms

Effects on Organisms - Coral Effects on Organisms - Coral ReefsReefs

o Coral reefs can be bleached (right) due Coral reefs can be bleached (right) due to increase in water temperatureto increase in water temperature• Affects coral symbiotes and makes them Affects coral symbiotes and makes them

more susceptible to diseases to which they more susceptible to diseases to which they would otherwise be immunewould otherwise be immune

Effect on Organisms - VegetationEffect on Organisms - VegetationBeech Tree RangeBeech Tree Range

Effects on Human HealthEffects on Human Health

o Increased number of heat-related Increased number of heat-related illnesses and deathsillnesses and deaths

Effects on AgricultureEffects on Agriculture

o Difficult to anticipateDifficult to anticipate• Productivity will increase in some areas and Productivity will increase in some areas and

decrease in othersdecrease in others

o Rise in sea level will inundate flood plains and Rise in sea level will inundate flood plains and river valleys (lush farmland)river valleys (lush farmland)

o Effect on pests is unknownEffect on pests is unknowno Warmer temperatures will decrease soil Warmer temperatures will decrease soil

moisture- requiring more irrigationmoisture- requiring more irrigationo Location (i.e. elevation and altitude) where Location (i.e. elevation and altitude) where

certain crops can be grown may have to certain crops can be grown may have to changechange

International ImplicationsInternational Implicationsof Climate Changeof Climate Change

o Developed vs. Developed vs. Developing Developing countriescountries• Differing self-Differing self-

interestsinterests• Differing ability to Differing ability to

meet the meet the challenges of challenges of climate changeclimate change

Dealing with Global Climate Dealing with Global Climate ChangeChange

o To avoid the worst of climate change, To avoid the worst of climate change, COCO22 levels must be stabilized at 550ppm levels must be stabilized at 550ppm• 50% higher than current levels50% higher than current levels

o Two ways to attempt to manage climate Two ways to attempt to manage climate changechange• MitigationMitigation

• Focuses on limiting greenhouse gas emissions to Focuses on limiting greenhouse gas emissions to moderate global climate changemoderate global climate change

• AdaptationAdaptation• Focuses on learning to live with to the Focuses on learning to live with to the

environmental changes and societal environmental changes and societal consequences brought about by global climate consequences brought about by global climate change change

Dealing with Global Climate Change- Dealing with Global Climate Change- Relationship Between Mitigation and Relationship Between Mitigation and

AdaptationAdaptation

Dealing with Global Climate Change- Dealing with Global Climate Change- MitigationMitigation

o Locate/invent alternative fuels to fossil Locate/invent alternative fuels to fossil fuelsfuels

o Increase efficiency of cars and trucksIncrease efficiency of cars and truckso Sequestering carbon before it is Sequestering carbon before it is

emittedemittedo Plant and Maintain trees to naturally Plant and Maintain trees to naturally

sequester carbonsequester carbon

Dealing with Global Climate Change- Dealing with Global Climate Change- AdaptationAdaptation

o Rising sea levels and coastal Rising sea levels and coastal populationspopulations• Move inlandMove inland• Construct dikes and leveesConstruct dikes and levees

o Adapt to shifting agricultural zonesAdapt to shifting agricultural zoneso NYC sewer lineNYC sewer line

International Efforts to Reduce International Efforts to Reduce Greenhouse Gas EmissionGreenhouse Gas Emission

o Kyoto ProtocolKyoto Protocol• Legally bindingLegally binding• Provides operational rules on reducing Provides operational rules on reducing

greenhouse gasesgreenhouse gases• US and Australia have not sign it- it will be US and Australia have not sign it- it will be

difficult to implement without US backingdifficult to implement without US backing

o http://www.irishtimes.com/newspaper/opinion/2009/0318/1224243006437.html

o http://news.bbc.co.uk/1/hi/sci/tech/7946476.stm