chapter 19 climate change and ozone depletion (we can get along!)

Chapter 19Chapter 19

Climate Change Climate Change

and and

Ozone Depletion Ozone Depletion (we (we cancan get along!) get along!)

Figure 20-1Figure 20-1

1991… …the Phillipines…

Mount Pinatubo erupts!

“The effects of the eruption were felt worldwide. It ejected roughly 10 billion metric tonnes (10 cubic kilometres) of magma, and 20 million tons of SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of aerosols into the stratosphere—more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C (0.9 °F), and ozone depletion temporarily increased substantially.” -Wikipedia

http://en.wikipedia.org/wiki/Sulfur_dioxide

http://en.wikipedia.org/wiki/Sulfur_dioxide

http://en.wikipedia.org/wiki/Particulate

http://en.wikipedia.org/wiki/Stratosphere

http://en.wikipedia.org/wiki/Krakatoa

http://en.wikipedia.org/wiki/Sulfuric_acid

http://en.wikipedia.org/wiki/Celsius

http://en.wikipedia.org/wiki/Fahrenheit

http://en.wikipedia.org/wiki/Ozone

Core Case Study: Studying a Volcano Core Case Study: Studying a Volcano to Understand Climate Changeto Understand Climate Change

A NASA scientist A NASA scientist predicted that the 1991 predicted that the 1991 Philippines explosion Philippines explosion would cool the average would cool the average temperature of the earth temperature of the earth by 0.5Cby 0.5Coo over a 15 over a 15 month period and then month period and then return to normal by return to normal by 1995.1995.

His predictions were His predictions were correct.correct.


Core Case Study: Studying a Volcano Core Case Study: Studying a Volcano to Understand Climate Changeto Understand Climate Change

The NASA climate change model was The NASA climate change model was correct.correct. The Mt. Pinatubo The Mt. Pinatubo modelmodel prediction successprediction success

convince scientists and policy makers that convince scientists and policy makers that climate model projections should be climate model projections should be taken taken seriously.seriously.

Other climate models have shown that global Other climate models have shown that global temperatures are temperatures are likelylikely to rise several degrees to rise several degrees during this century.during this century.

Chapter Overview QuestionsChapter Overview Questions

How have the earth’s How have the earth’s temperaturetemperature and and climateclimate changed in the changed in the pastpast??

How might the earth’s How might the earth’s temperaturetemperature and and climateclimate change in the change in the futurefuture??

What What factors influencefactors influence the earth’s average the earth’s average temperature?temperature?

What are some possible What are some possible beneficialbeneficial and and harmful harmful effects of a effects of a warmer earthwarmer earth??

Chapter Overview Questions (cont’d)Chapter Overview Questions (cont’d)

How can we How can we slowslow projected increases in the projected increases in the earth’s temperature or earth’s temperature or adaptadapt to such to such changes?changes?

How have human activities depleted How have human activities depleted ozone in ozone in the stratospherethe stratosphere, and why should we care?, and why should we care?

PAST CLIMATE AND THE PAST CLIMATE AND THE GREENHOUSE EFFECTGREENHOUSE EFFECT

Over the past 900,000 years, the Over the past 900,000 years, the tropospheretroposphere has experienced prolonged periods of global has experienced prolonged periods of global cooling and global warming.cooling and global warming.

For the past For the past 1,000 years1,000 years, temperatures have , temperatures have remained remained fairly stablefairly stable but began to rise but began to rise during the last century.during the last century.

PAST CLIMATE AND THE PAST CLIMATE AND THE GREENHOUSE EFFECTGREENHOUSE EFFECT


Fig. 20-2a, p. 465

Thousands of years ago

Average temperature over past 900,000 years

Ave

rag

e su

rfac

e te

mp

erat

ure

(°C

)

Fig. 20-2c, p. 465

Average temperature over past10,000 years = 15°C (59°F)

Tem

per

atu

re c

han

ge

(C°)

Temperature change over past 22,000 years

Agriculture established

End oflast iceage

Years ago

Fig. 20-2d, p. 465

Tem

per

atu

re c

han

ge

(C°)

Temperature change over past 1,000 years

Year

Fig. 20-2b, p. 465

Ave

rag

e su

rfac

e te

mp

erat

ure

(°C

)

Year

Average temperature over past 130 years

From website “Logicalscience. com”

How Do We Know What How Do We Know What Temperatures Were in the Past?Temperatures Were in the Past?

Scientists analyze Scientists analyze tiny air bubbles tiny air bubbles trapped in ice cores trapped in ice cores learn about past:learn about past: troposphere troposphere

compositioncomposition.. temperature trendstemperature trends.. greenhouse gas greenhouse gas

concentrationsconcentrations.. solarsolar,, snowfallsnowfall, and , and

forest fire activityforest fire activity..Figure 20-3Figure 20-3

Ice Core AnalysisIce Core Analysis

National Ice Core LaboratoryNational Ice Core Laboratory

Ice Core AnalysisIce Core Analysis

A “thin cut” slice of an ice core.

How Do We Know What How Do We Know What Temperatures Were in the Past?Temperatures Were in the Past?

In 2005, an ice core In 2005, an ice core showed that COshowed that CO22

levels in the levels in the troposphere are the troposphere are the highest they have highest they have been in 650,000 been in 650,000 years.years.


Fig. 20-4, p. 466

Co

nce

ntr

atio

n o

f ca

rbo

n d

ioxi

de

in t

he

atm

osp

her

e (p

pm

)

Var

iati

on

of

tem

per

atu

re (

C°)

fro

m c

urr

ent

leve

l

Thousands of years before present

End of last ice age

Temperature change

Carbon dioxide

280 ppm in 1725

384 ppm in 2007

392 ppm in 2011

The Natural Greenhouse EffectThe Natural Greenhouse Effect Four major factors shape the earth’s climate:Four major factors shape the earth’s climate:

The The sunsun.. Greenhouse effectGreenhouse effect warms the earth’s lower warms the earth’s lower

troposphere and surface because of the troposphere and surface because of the presence of presence of greenhouse gasesgreenhouse gases..

OceansOceans store COstore CO22 and heat and heat, , evaporate and evaporate and receive waterreceive water, , move stored heatmove stored heat to other parts of to other parts of the world.the world.

Natural cooling processNatural cooling process through water vapor in through water vapor in the troposphere (heat rises).the troposphere (heat rises).• EvaporationEvaporation cools the Earth’s surface cools the Earth’s surface• CondensationCondensation in clouds releases heat in upper in clouds releases heat in upper

tropospheretroposphere

Major Greenhouse GasesMajor Greenhouse Gases

The major greenhouse gases in the lower The major greenhouse gases in the lower atmosphere are, IN ORDER:atmosphere are, IN ORDER:

1.1. water vapor-water vapor- most important greenhouse gas most important greenhouse gas

2.2. carbon dioxide-carbon dioxide- greatest effect from greatest effect from human human activitiesactivities

3.3. methane-methane- CH CH4 4 -more powerful greenhouse gas -more powerful greenhouse gas

per moleculeper molecule than CO than CO22, but less of it than CO, but less of it than CO22

4.4. nitrous oxide-nitrous oxide- N N22O -comes from fertilizers and O -comes from fertilizers and

planting riceplanting rice

Major Greenhouse GasesMajor Greenhouse Gases The major greenhouse gases in the lower The major greenhouse gases in the lower

atmosphere are:atmosphere are: water vaporwater vapor carbon dioxidecarbon dioxide

methane methane nitrous oxide.nitrous oxide. These gases have These gases have always been presentalways been present in the in the

earth’s troposphere in varying concentrations.earth’s troposphere in varying concentrations. Fluctuations in these gasesFluctuations in these gases, plus , plus changes in changes in

solar outputsolar output and and Earth’s Mankelovich cyclesEarth’s Mankelovich cycles are are the major factors causing the changes in the major factors causing the changes in tropospheric temperature over the past 400,000 tropospheric temperature over the past 400,000 years.years.

Major Greenhouse Major Greenhouse GasesGases

Increases in average Increases in average concentrations of three concentrations of three greenhouse gases in the greenhouse gases in the troposphere between 1860 troposphere between 1860 and 2004, mostly due to and 2004, mostly due to

Fossil fuel burningFossil fuel burning (CO(CO22 & CH & CH44))

Deforestation Deforestation (CO(CO22 & N & N22O)O)

AgricultureAgriculture (N(N22O)O)


Fig. 20-5a, p. 467

280 ppm in 1725

384 ppm in 2007

392 ppm in 2011

Fig. 20-5b, p. 467

Fig. 20-5c, p. 467

CLIMATE CHANGE AND HUMAN CLIMATE CHANGE AND HUMAN ACTIVITIESACTIVITIES

Evidence that the earth’s troposphere is Evidence that the earth’s troposphere is warming:warming: The 20The 20thth century was the century was the hottest hottest

centurycentury in the in the past 1000 yearspast 1000 years..

The The 14 hottest years14 hottest years since 1861 have since 1861 have been since 1990been since 1990

CLIMATE CHANGECLIMATE CHANGE

Since 1900, the earth’s Since 1900, the earth’s average average

tropospheric temperaturetropospheric temperature has risen has risen 0.6 C0.6 C°°..

Over the past 50 years, Over the past 50 years, Arctic temperaturesArctic temperatures have have risen almost twice as fastrisen almost twice as fast as those in the as those in the rest of the world.rest of the world.

CLIMATE CHANGECLIMATE CHANGE

GlaciersGlaciers and and floating sea icefloating sea ice are melting and are melting and shrinking at increasing rates.shrinking at increasing rates.

The The range of specific species range of specific species is moving to is moving to higher altitudeshigher altitudes (up mountains) and (up mountains) and higher higher latitudes.latitudes.• What happenes to the size of a species’ habitat What happenes to the size of a species’ habitat

as it moves up a mountain?as it moves up a mountain?

Fig. 19-5a, p. 501

Fig. 19-5b, p. 501

Fig. 19-6, p. 501

Sept. 1979 Sept. 2007

Russia Russia

North pole

GreenlandNorth pole Greenland

Alaska (U.S.) Alaska (U.S.)Canada Canada

Effects on Biodiversity: Effects on Biodiversity: Winners and LosersWinners and Losers

Possible effects of Possible effects of global warming on global warming on the geographic the geographic range of beech range of beech trees based on trees based on ecological evidence ecological evidence and computer and computer models.models.

NextNext

Fig. 20-13, p. 478

Presentrange

Overlap

Futurerange

Beech

CLIMATE CHANGE AND HUMAN CLIMATE CHANGE AND HUMAN ACTIVITIESACTIVITIES

Warmer temperatures in Alaska, Russia, and the Warmer temperatures in Alaska, Russia, and the Arctic are Arctic are melting permafrost,melting permafrost, releasing more releasing more COCO22 and CH and CH44 into the troposphere (feedback into the troposphere (feedback

loop…which kind, positive or negative?)loop…which kind, positive or negative?)

During the last century, the world’s During the last century, the world’s sea level rosesea level rose by 10-20 cm, mostly due to by 10-20 cm, mostly due to runoff from meltingrunoff from melting of of land-based ice and the land-based ice and the expansion of ocean waterexpansion of ocean water as temperatures rise.as temperatures rise.

Melting Permafrost- “Drunken Forests”Melting Permafrost- “Drunken Forests”

The Scientific Consensus about The Scientific Consensus about Future Climate ChangeFuture Climate Change

There is strong evidence that human There is strong evidence that human activities will play an important role in activities will play an important role in changing the earth’s climate during this changing the earth’s climate during this century.century.

Coupled General Circulation Models (CGCMs) Coupled General Circulation Models (CGCMs) couplecouple, or combine, the effects of the , or combine, the effects of the atmosphereatmosphere and the and the oceansoceans on climate. on climate.

CCoupledoupled G General eneral CCirculationirculation M Modelodel of the Earth’s Climateof the Earth’s Climate

Simplified Simplified modelmodel of major of major processes that processes that interactinteract to to determine the determine the average average temperaturetemperature and and greenhouse greenhouse gas contentgas content of of the the troposphere.troposphere.


Sun

Stepped Art

Aerosols

Greenhousegases

Warmingfrom

decrease

Cooling from

increase

CO2 removal by plants and

soil organisms

CO2 emissions from land

cleaning, fires, and decay

Heat andCO2 removal

Heat andCO2 emissions

Ice and snow cover

Natural and human emissions

Land and soil biota

Long-termstorage

Deep ocean

Shallow ocean

Troposphere

Fig. 20-6, p. 469

Factors that cool

Factors that warm

Measured and projected changes in the Measured and projected changes in the average temperature of the atmosphere (2005).average temperature of the atmosphere (2005).

↑ ↑ 0.6 0.6 °C °C since 1900 since 1900 Consensus Consensus

projection is projection is 5 5 °C ↑ °C ↑ by 2100by 2100 if we “do if we “do nothing”nothing”

Consensus is Consensus is 4 4 °C °C ↑ could threaten ↑ could threaten civilizationcivilization as we as we know itknow it


Fig. 20-7, p. 470

Most recent data suggests that temperatures are increasing even faster than the worst-case 2007 IPCC estimates

Why Should We Be Concerned about Why Should We Be Concerned about a Warmer Earth?a Warmer Earth?

A A rapid increase (non-linear response rapid increase (non-linear response pattern)pattern) in the temperature of the in the temperature of the troposphere during this century would give us troposphere during this century would give us little timelittle time to deal with its harmful effects. to deal with its harmful effects.

As a As a prevention strategyprevention strategy scientists urge to cut scientists urge to cut global COglobal CO2 2 emissions emissions 50%50% over the next 50 over the next 50 years…. “50/50”years…. “50/50” This This could could prevent changes in the earth’s climate prevent changes in the earth’s climate

system that might last for tens of thousands of system that might last for tens of thousands of years (due to many positive feedback loops)years (due to many positive feedback loops)

FACTORS AFFECTING THE FACTORS AFFECTING THE EARTH’S TEMPERATUREEARTH’S TEMPERATURE

Some factors can Some factors can amplifyamplify (positive feedback) (positive feedback) and some can and some can dampen dampen (negative feedback) (negative feedback) projected global warming. projected global warming.

There is uncertainty about There is uncertainty about how much COhow much CO22 and heatand heat the the oceans can removeoceans can remove from the from the troposphere and troposphere and how longhow long the heat and CO the heat and CO22 might remain there.might remain there.

Warmer temperatures create Warmer temperatures create more cloudsmore clouds that could warm or cool the troposphere.that could warm or cool the troposphere.

Human Effects on the Carbon CycleHuman Effects on the Carbon Cycle Burning Burning fossil fuelsfossil fuels for energy for energy

ResidentialResidential CommercialCommercial IndustrialIndustrial TransportationTransportation

Clearing forestsClearing forests for agriculture & forest for agriculture & forest productsproducts

Covering landCovering land with pavement with pavement Exponential Exponential populationpopulation growth growth

Effects of Higher Effects of Higher COCO2 2 Levels on PhotosynthesisLevels on Photosynthesis

Increased COIncreased CO22 in the troposphere can in the troposphere can

increase plant photosynthesisincrease plant photosynthesis (PS) but: (PS) but: The increase in PS would The increase in PS would slowslow as the plants reach as the plants reach

maturity.maturity. Carbon stored by the plants would be returned to Carbon stored by the plants would be returned to

the atmosphere as COthe atmosphere as CO22 when the when the plants die & plants die &

decaydecay Increased PS decreases the amount of carbon Increased PS decreases the amount of carbon

stored in the soilstored in the soil..

FACTORS AFFECTING THE FACTORS AFFECTING THE EARTH’S TEMPERATUREEARTH’S TEMPERATURE

Aerosol and soot pollutantsAerosol and soot pollutants produced by produced by human activities can human activities can warmwarm (SO (SO44 aerosols) or aerosols) or

coolcool (soot particulates) the atmosphere, but (soot particulates) the atmosphere, but such effects will decrease with any decline in such effects will decrease with any decline in outdoor air pollution.outdoor air pollution.

Warmer air can Warmer air can release methane gasrelease methane gas stored stored in bogs, wetlands, and melting tundra soils in bogs, wetlands, and melting tundra soils and accelerate global warming (feedback?).and accelerate global warming (feedback?).

EFFECTS OF GLOBAL WARMINGEFFECTS OF GLOBAL WARMING

A warmer climate would have A warmer climate would have beneficialbeneficial and and harmfulharmful effects but poor nations in the tropics effects but poor nations in the tropics would suffer the most.would suffer the most.

Some of the world’s Some of the world’s floating icefloating ice and and land-land-based glaciersbased glaciers are slowly melting and are are slowly melting and are helping warm the troposphere by helping warm the troposphere by reflecting reflecting less sunlightless sunlight (“albedo”) back into space (“albedo”) back into space (feedback?).(feedback?).

Rising Sea LevelsRising Sea Levels

During this century During this century rising seas levels rising seas levels are projected to are projected to flood flood low-lying urban low-lying urban areasareas, , coastal coastal estuariesestuaries, , wetlandswetlands, , coral reefscoral reefs, and , and barrier islandsbarrier islands and and beaches (effects?)beaches (effects?)

NextNext

Fig. 20-10, p. 475

High ProjectionNew Orleans,Shanghai, andother low-lyingcities largelyunderwater

Year

Low Projection

MediumProjection

More than a third ofU.S. wetlands underwater

Mea

n S

ea-L

evel

Ris

es (

cen

tim

eter

s)

4 inches

35 inches

IPCC (2000) Projections “very likely” (90-99% confidence level)


Changes in average sea level over the past Changes in average sea level over the past 250,000 years based on data from ocean 250,000 years based on data from ocean cores.cores.



If sea levels rise If sea levels rise by 9-88cm by 9-88cm during this during this century, most of century, most of the Maldives the Maldives islands and their islands and their coral reefs will coral reefs will be flooded.be flooded.


Fig. 20-12, p. 476

Warm, shallowcurrent

Cold, salty,deep current

Changing Ocean CurrentsChanging Ocean Currents

Global warming could alter ocean currents Global warming could alter ocean currents and cause both excessive warming and and cause both excessive warming and severe cooling.severe cooling.

NextNext

It has recently been shown that the potential shifting of ocean currents is less of a threat than we thought before.

EFFECTS OF GLOBAL WARMINGEFFECTS OF GLOBAL WARMING

Oceans remove 25-30% of tropospheric COOceans remove 25-30% of tropospheric CO22

A warmer troposphere can A warmer troposphere can decreasedecrease the the ability of the ocean to remove and store COability of the ocean to remove and store CO22

by by decreasing the nutrient supply for calcareous decreasing the nutrient supply for calcareous

phytoplankton that phytoplankton that store COstore CO22 in their calcium in their calcium

carbonate (CaCOcarbonate (CaCO33) shells, by potentially ) shells, by potentially

disrupting wind and ocean currents that provide disrupting wind and ocean currents that provide nutrients via nutrients via upwellingupwelling (feedback?) (feedback?)

EFFECTS OF GLOBAL WARMINGEFFECTS OF GLOBAL WARMING Increasing the acidityIncreasing the acidity of ocean water: of ocean water:

• COCO22 is dissolved in the ocean as is dissolved in the ocean as carbonic acidcarbonic acid, , HH22COCO3 3

• increased acidity increased acidity interferesinterferes with calcareous with calcareous phytoplankton shell formation phytoplankton shell formation

• Increased acidity Increased acidity dissolvesdissolves existing deposits of existing deposits of CaCOCaCO3 3 (feedback?)(feedback?)

COCO22 is is less solubleless soluble in warmer water in warmer water (feedback?)(feedback?)

EFFECTS OF GLOBAL WARMINGEFFECTS OF GLOBAL WARMING Global warming will lead to prolonged Global warming will lead to prolonged heat heat

waves and droughtswaves and droughts in some areas (Africa, in some areas (Africa, Asia, & Western USA) and Asia, & Western USA) and prolonged heavy prolonged heavy rainsrains and increased flooding in other areas and increased flooding in other areas (Europe; more intense hurricanes and (Europe; more intense hurricanes and typhoons).typhoons).

Between 1979 & 2002, the area of Between 1979 & 2002, the area of Earth’s land experiencing severe Earth’s land experiencing severe drought increased between 15% and drought increased between 15% and 30%30%

EFFECTS OF GLOBAL WARMINGEFFECTS OF GLOBAL WARMING In a warmer world, In a warmer world, agricultural productivityagricultural productivity

may may increaseincrease in some areas (Canada & in some areas (Canada & Russia) and Russia) and decreasedecrease in others (Asia & in others (Asia & Africa)….why?Africa)….why?

Crop and fish productionCrop and fish production in some areas could in some areas could be reduced by rising sea levels that would be reduced by rising sea levels that would flood river deltas (why?).flood river deltas (why?).

Global warming will Global warming will increase deathsincrease deaths from: from: Heat and disruption of food supply.Heat and disruption of food supply. Spread of Spread of tropical diseasestropical diseases to temperate regions. to temperate regions. Increase the number of Increase the number of environmental refugeesenvironmental refugees..

DEALING WITH GLOBAL WARMINGDEALING WITH GLOBAL WARMING

Climate change is such a difficult problem to Climate change is such a difficult problem to deal with because:deal with because: The problem is The problem is globalglobal.. The effects will last a The effects will last a long timelong time.. The problem is a The problem is a long-termlong-term political issue. political issue. The harmful and beneficial impacts of climate The harmful and beneficial impacts of climate

change are change are not spread evenlynot spread evenly.. Many actions that might reduce the threat are Many actions that might reduce the threat are

controversialcontroversial because they can because they can impact impact economies and lifestyles.economies and lifestyles.


Two ways to deal with global warming:Two ways to deal with global warming: MitigationMitigation that that reduces greenhouse gasreduces greenhouse gas

emissions.emissions.

AdaptationAdaptation, where we recognize that some , where we recognize that some warming is unavoidable and devise strategies to warming is unavoidable and devise strategies to reduce its harmful effectsreduce its harmful effects..

Fig. 20-17, p. 485

Move hazardous material storage tanks away

from coast

Connect wildlifereserves with corridors

Develop crops thatneed less water

Waste less water

Move people awayfrom low-lyingcoastal areas

Stockpile 1- to 5-yearsupply of key foods

Expand existingwildlife reserves

toward poles(why?)

Prohibit new constructionon low-lying coastal areasor build houses on stilts

Adaptation Strategies

Fig. 20-14, p. 481

Cut fossil fuel use (especially coal)

Shift from coal to natural gas

Improve energy efficiency

Shift to renewable energy resources

Transfer energy efficiency and renewable energy technologies to developing countries

Reduce deforestation

Use more sustainableagriculture and forestry

Limit urban sprawl

Reduce poverty

Slow population growth

Remove CO2 from smoke stack and vehicle emissions

Store (sequester)CO2 by planting trees

Sequester CO2 deep underground

Sequester CO2 in soil by using no-till cultivation and taking cropland out of production

Sequester CO2 in the deep ocean

Repair leaky natural gas pipelines and facilities

Use animal feeds that reduce CH4 emissions by belching cows

Solutions

Global Warming

Prevention Cleanup

Solutions: Reducing the ThreatSolutions: Reducing the Threat

We can We can improve improve energy efficiencyenergy efficiency

rely more on rely more on carbon-free renewablecarbon-free renewable energy energy resourcesresources

find ways to keep much of the COfind ways to keep much of the CO22 we produce we produce

out of the troposphereout of the troposphere (Carbon Capture & (Carbon Capture & Sequestration a.k.a. CCS)Sequestration a.k.a. CCS)

Removing and Storing CORemoving and Storing CO22

Methods for Methods for removing COremoving CO22

from the from the atmosphere or atmosphere or from from smokestacks and smokestacks and storing storing (sequestering) it.(sequestering) it.


Fig. 20-15, p. 482

Tree plantation

Coal powerplant

Tanker deliversCO2 from plantto rig

Oil rig

CO2 is pumpeddown from rig for deep ocean disposal

Spent oil reservoir isused for CO2 deposit

Abandonedoil field Crop field

Spent oil reservoir isused for Crop field

Switchgrass

= CO2 deposit

= CO2 pumping

CO2 deposit CO2 is pumped down to reservoir through abandoned oil field

Problems with CCSProblems with CCS UnprovenUnproven technology technology PromotesPromotes continued use of fossil fuels continued use of fossil fuels Requires huge Requires huge government subsidiesgovernment subsidies

that draw funds from other solutionsthat draw funds from other solutions There can be There can be no leaksno leaks for any reason for any reason

DEALING WITH GLOBAL WARMINGDEALING WITH GLOBAL WARMING Governments can Governments can

taxtax greenhouse gas emissions and/or carbon- greenhouse gas emissions and/or carbon-based energy usebased energy use

increaseincrease subsidies and tax breakssubsidies and tax breaks for saving for saving energyenergy

decreasedecrease subsidies and tax breakssubsidies and tax breaks for fossil for fossil fuels.fuels.


A crash program to A crash program to slowslow and and adapt toadapt to climate climate change change nownow is very likely to is very likely to cost less cost less than than waiting and having to deal with its harmful waiting and having to deal with its harmful effects later.effects later.

As usual, “An ounce of prevention is worth a As usual, “An ounce of prevention is worth a pound of cure”pound of cure”

WHAT IS BEING DONE TO REDUCE WHAT IS BEING DONE TO REDUCE GREENHOUSE GAS EMISSIONS?GREENHOUSE GAS EMISSIONS?

Getting countries to agreeGetting countries to agree on reducing their on reducing their greenhouse emissions is difficult.greenhouse emissions is difficult.

But…A 2006 poll showed that But…A 2006 poll showed that 83% of 83% of AmericansAmericans want want more leadershipmore leadership from federal from federal government on dealing with global warming.government on dealing with global warming.

International Climate Negotiations: International Climate Negotiations: The The Kyoto Protocol (1997)Kyoto Protocol (1997)

Treaty on global warming which first phase went Treaty on global warming which first phase went into effect January, 2005 with into effect January, 2005 with 189 countries189 countries participating.participating.

It requires It requires 38 participating developed countries38 participating developed countries to to cut their emissions of COcut their emissions of CO22, CH, CH44, and N, and N22O to O to 5.2% 5.2% below their 1990 levels by 2012.below their 1990 levels by 2012.

Developing countries were excluded.Developing countries were excluded.• The U.S. and Australia did not sign, but California The U.S. and Australia did not sign, but California

(world’s 6(world’s 6thth largest economy) and Maine are participating. largest economy) and Maine are participating.• U.S. did not sign because developing countries such as U.S. did not sign because developing countries such as

China, India and BrazilChina, India and Brazil were excluded. were excluded.

Moving Beyond the Kyoto ProtocolMoving Beyond the Kyoto Protocol Countries could work together to develop a Countries could work together to develop a

new international approachnew international approach to slowing global to slowing global warming (much has changed since 1997)warming (much has changed since 1997) The Kyoto Protocol will have little effect on future The Kyoto Protocol will have little effect on future

global warming without support and action by the global warming without support and action by the U.S., China, and India.U.S., China, and India.

November 29- December 9, 2011: Durban, November 29- December 9, 2011: Durban, South Africa Climate Change ConferenceSouth Africa Climate Change Conference See Forbes article See Forbes article

http://www.forbes.com/sites/ericagies/2011/11/28/chttp://www.forbes.com/sites/ericagies/2011/11/28/climate-treaty-would-actually-be-good-for-business/limate-treaty-would-actually-be-good-for-business/

Actions by Some Countries, States, Actions by Some Countries, States, and Businessesand Businesses

In 2005, the In 2005, the EU EU proposed a plan to reduce proposed a plan to reduce COCO22 levels by 1/3 levels by 1/3rdrd by 2020. by 2020.

Global companiesGlobal companies (BP, IBM, Toyota) have (BP, IBM, Toyota) have established targets to reduce their established targets to reduce their greenhouse emissions to 10-65% below greenhouse emissions to 10-65% below 1990 levels by 2010.1990 levels by 2010.


CaliforniaCalifornia has adopted a goal of reducing its has adopted a goal of reducing its greenhouse gas emission to 1990 levels by greenhouse gas emission to 1990 levels by 2020, and 80% below by 2050.2020, and 80% below by 2050.

The US EPA refused California’s request to The US EPA refused California’s request to set tough new standards(!)set tough new standards(!)


BP spent BP spent $20 million$20 million to lower it’s greenhouse to lower it’s greenhouse gas emissions to 10% below 1990 levels.gas emissions to 10% below 1990 levels.

Took 3 years, from 1998 to 2001Took 3 years, from 1998 to 2001

Saved $250 millionSaved $250 million

Fig. 20-16, p. 485

Reducing CO2 Emissions

• Drive a fuel-efficient car, walk, bike, carpool, and use mass transit

• Use energy-efficient windows

• Use energy-efficient appliances and lights

• Heavily insulate your house and seal all drafts

• Reduce garbage by recycling and reuse (why?)

• Insulate your hot water heater

• Use compact fluorescent bulbs

• Plant trees to shade your house during summer

• Set water heater no higher than 49°C (120°F)

• Wash laundry in warm or cold water

• Use low-flow shower head

• Buy products from companies that are trying to reduce their impact on climate

• Demand that the government make climate change an urgent priority

What Can You Do?

OZONE DEPLETION IN THE OZONE DEPLETION IN THE STRATOSPHERESTRATOSPHERE

During four During four months of each months of each year up to year up to halfhalf of of the ozone in the the ozone in the stratosphere over stratosphere over AntarcticaAntarctica and a and a smaller amount smaller amount over the Arcticover the Arctic is is depleted.depleted.



Less ozoneLess ozone in the in the stratospherestratosphere allows for allows for more harmful UV radiationmore harmful UV radiation to reach the to reach the earth’s surface.earth’s surface. The ozone layer keeps about The ozone layer keeps about 95%95% of the sun’s of the sun’s

harmful UV radiation from reaching the earth’s harmful UV radiation from reaching the earth’s surface.surface.

Chlorofluorocarbons (CFCs)Chlorofluorocarbons (CFCs) have lowered the have lowered the average concentrations of ozone in the average concentrations of ozone in the stratosphere.stratosphere.

In 1988 CFCs were no longer manufactured, due In 1988 CFCs were no longer manufactured, due to the to the Montreal ProtocolMontreal Protocol

SunOnce free, the chlorine atom is off to attack another ozone moleculeand begin the cycle again.

A free oxygen atom pulls the oxygen atom off the chlorine monoxide molecule to form O2.

The chlorine atom and the oxygen atom join to form a chlorine monoxide molecule (ClO).

UV radiation

Cl Cl

ClC

F

The chlorine atom attacks an ozone (O3) molecule, pulling an oxygen atom off it and leaving an oxygen molecule (O2).

Cl

Cl

OO

O

Cl

ClO

ClO

OO

OO

Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl3, breaking off a chlorine atom and leaving CFCl2.

O

Fig. 20-18, p. 486

Stepped Art


Since 1976, in Antarctica, ozone levels have markedly Since 1976, in Antarctica, ozone levels have markedly decreased during October and November.decreased during October and November.



Ozone thinningOzone thinning: caused by CFCs and other : caused by CFCs and other ozone depleting chemicals (ODCs).ozone depleting chemicals (ODCs). Increased UV radiation reaching the earth’s Increased UV radiation reaching the earth’s

surface from ozone depletion in the stratosphere surface from ozone depletion in the stratosphere is harmful to human health, crops, forests, is harmful to human health, crops, forests, animals, and materials such as plastic and animals, and materials such as plastic and paints.paints.

Human Health• Worse sunburn• More eye cataracts• More skin cancers• Immune system suppression

Food and Forests• Reduced yields for some crops• Reduced seafood supplies from reduced phytoplankton• Decreased forest productivity for UV-sensitive tree species

Wildlife• Increased eye cataracts in some species• Decreased population of aquatic species sensitive to UV radiation• Reduced population of surface phytoplankton• Disrupted aquatic food webs from reduced phytoplankton

Air Pollution and Materials• Increased acid deposition• Increased photochemical smog• Degradation of outdoor paints and plastics

Global Warming• Accelerated warming because of decreased ocean uptake of CO2 from atmosphere by phytoplankton and CFCs acting as greenhouse gases

Effects of Ozone DepletionNatural Capital Degradation

Fig. 20-21, p. 488

Fig. 20-22, p. 489

This long-wavelength(low-energy) form of UV radiation causes aging of the skin, tanning, and sometimes sunburn. It penetrates deeply and may contribute to skin cancer.

This shorter-wavelength (high-energy) formof UV radiation causes sunburn, prematureaging, and wrinkling. It is largely responsiblefor basal and squamous cell carcinomasand plays a role in malignant melanoma.

Epidermis

Squamous Cell Carcinoma

Basal Cell Carcinoma

Melanoma

Sweatgland

Dermis

Squamous cells

Thin layer ofdead cells

Basal layer

Melanocyte cells

Bloodvessels

UltravioletB

UltravioletA

Hair

Basal cell

PROTECTING THE OZONE LAYERPROTECTING THE OZONE LAYER

To reduce ozone To reduce ozone depletion, we depletion, we must must stop stop producing all producing all ozone-depleting ozone-depleting chemicals.chemicals.

NextNext

Fig. 20-23, p. 490

What Can You Do?

• Stay out of the sun, especially between 10 A.M. and 3 P.M.

• Do not use tanning parlors or sunlamps.

• When in the sun, wear protective clothing and sun– glasses that protect against UV-A and UV-B radiation.

• Be aware that overcast skies do not protect you.

• Do not expose yourself to the sun if you are takingantibiotics or birth control pills.

• Use a sunscreen with a protection factor of 15 or 30

anytime you are in the sun if you have light skin. • Examine your skin and scalp at least once a month for moles or warts that change in size, shape, or color or sores that keep oozing, bleeding, and crusting over. Ifyou observe any of these signs, consult a doctor immediately.

Reducing Exposure to UV Radiation

chapter 19 climate change and ozone depletion (we can get along!)

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