XV. Global Warming's Effects on Forests and Biodiversity

• The makeup and location of world's forests will change

• Due to seed movement by animals forests will move further North

• Mountaintops that are far North will become extinct- no where to go-causing release of carbon

• Wildfires will happen in up to 90% of forests

• Huge amounts of carbon dioxide will then accelerate global warming

• Reductions in biodiversity due to mass extinction of animals that can't migrate

• Fish would die because the temp would rise

Presentrange

Futurerange

Overlap

Fig. 18.13, p. 459

XVI. What could Happen to Sea Levels?

• They will rise because ocean expands when heated • Will rise because of melting glaciers and ice sliding into the

sea • Sea levels will rise by as much as 48 cm.• Will effect cities near sea level (about 1/3 of world's people)

would be flooded • Some islands would completely disappears• Beaches on East Coast might disappear within 25 to 50 years • Move barrier islands further inland, accelerate erosion,

contaminate coastal aquifers with salt water •

Today’s sea level

Years before present Present

250,000 200,000 150,000 100,000 50,000 0

–130

0

–426

0

Hei

ght a

bove

or b

elow

pres

ent s

ea le

vel (

met

ers)

Hei

ght b

elow

pre

sent

sea

leve

l (fe

et)

Fig. 18.11, p. 456

XVII. How Might Weather Extremes Change Our Life

• More air will move across the surface because more heat is retained in climate system

• There may be higher precipitation, clashing fronts and more violent weather

• Increased intensity of hurricanes, typhoons and tornadoes

• Financial challenges for insurance companies who have to pay billions of dollars to flood victims

• Some companies are dropping their coverage or raising prices to be prepared and working with the government to decrease possible global warming

XVIII. How Might Human Health Be Affected

• Global warming will bring more heat waves(double number of deaths) increase asthma and bronchitis

• Disrupt supplies of food and water• Alter disease patterns• Insect diseases from tropical areas • Higher humidity levels • Rise in fungal skin diseases • Speed up bacterial growth • Climate change would lead to a large number of environmental refugees• Illegal migration would increase • Serious problems for foreign military and economic security policies of

nations could occur

• Increased deaths from heat and disease

• Disruption of food and water supplies

• Spread of tropical diseases to temperate areas

• Increased respiratory disease• Increased water pollution from

coastal flooding

Human Health

• Rising sea levels• Flooding of low-lying islands and

coastal cities• Flooding of coastal estuaries,

wetlands, and coral reefs• Beach erosion• Disruption of coastal fisheries• Contamination of coastal

aquifiers with salt water

Sea Level and Coastal Areas

• Changes in forest composition and locations

• Disappearance of some forests

• Increased fires from drying

• Loss of wildlife habitat and species

Forests

• Changes in water supply

• Decreased water quality

• Increased drought

• Increased flooding

Water Resources

• Shifts in food-growing areas• Changes in crop yields• Increased irrigation

demands• Increased pests, crop

diseases, and weeds in warmer areas

Agriculture

• Extinction of some plant and animal species

• Loss of habitats

• Disruption of aquatic life

Biodiversity

• Prolonged heat waves and droughts

• Increased flooding

• More intense hurricanes, typhoons, tornadoes, and violent storms

Weather Extremes

• Increased deaths

• More environmental refugees

• Increased migration

Human Population

Fig. 18.12, p. 458

XIX. Solutions: Dealing with the threat of Global Warming: Do More Research or Act

Now? • 3 schools of thought: • 1 No Problem is a minority view- global warming is not a

threat but a hoax. • 2. Wait and See- Wait until more info is available about the

global climate system. Why spend hundreds of billions of dollars phasing out fossil fuels and replacing deforestation with reforestation to help ward off something that might not happen.

• 3 Precautionary principle- take action instead of doing research

• 4. As a result of uncertainties in climate models scientists estimate that the projections from current climate models for the next 50-100 years could be half wrong or twice the current projections

XX. How can we slow Possible Global Warming?

• We must reduce current global CO2 emissions by 66-83% • Solutions: • a. quickest and cheapest way is to use energy more efficiently • b. increased use of nuclear energy• c. using natural gas- help to make the 40-50 year transition to an age of

energy efficiency and renewable energy • d. phase out gov’t subsidies for fossil fuels over a decade/gradually phase

in carbon taxes on fossil fuels• e. shift to renewable energy sources• f. reduce deforestation• g. slow population growth • h. reduce emissions of methane from leaking pipes and landfills• i. Increase government subsidies for renewable resources

XX. How can we slow Possible Global Warming?

• 1997- ECONOMISTS & Nobel laureates signed statement:

• a. sound economic analysis shows that greenhouse emissions can be out without harming American living standards

• b. calling for carbon taxes as part of an international system of tradable permits for greenhouse gas emissions

• Carbon tax based on • polluter- pays principle-

requires industries & consumers to pay directly for the full environmental costs of the fuels they use

• agree to global & national limits on greenhouse gas emissions

XXI. Can Technofixes save us? • Technofixes- technological solutions for dealing with possible

global warming • Adding iron to oceans-would remove more CO2 through

photosynthesis • Unfurling gigantic foil-surfaced sun mirrors in space to reduce

solar input. • Injecting sunlight - reflecting sulfate particulates into the

stratosphere - mimics cooling effects of giant volcanic eruptions

• Massive reforestation, we need to plant trees in an area the size of Australia

• Injecting CO2 into the ground or deep ocean

Prevention Cleanup

Cut fossil fueluse (especiallycoal)

Shift from coalto natural gas

Transfer energyefficiency andrenewable energytechnologiesto developingcountries

Improve energyefficiency

Shift torenewableenergy resources

Reducedeforestation

Use sustainableagriculture

Slow populationgrowth

Remove CO2

from smokestackand vehicleemissions

Store (sequesterCO2 by plantingtrees)

Sequester CO2

underground

Sequester CO2 in soil

Sequester CO2 in deep ocean

Fig. 18.14, p. 461

XXII. What has been done to reduce Greenhouse Gas emissions?

• 2,200 delegates-161 nations met in Kyoto, Japan negotiated treaty to help slow global warming

• The goal: • a. between 2008 & 2012: 12-38 developed countries should

have cut greenhouse emissions to an average of 5.2% below 1990 levels

• b. developing countries won’t be required to cut • c. there would be penalties for countries that violate treaty

laws • d. forested countries get a break in their quotas • e. since the treaty was made, US cut greenhouse emissions by

7%, Japan by 6% and European countries by 8%

XXIII. How can we prepare for possible global warming?

• waste less _energy__ • develop ____crops_ that need less water • move hazardous materials (storage tanks) away from

the __coast • prohibit new construction or remolding on low-lying

coastal areas • stockpile 1-5 years supply of key food• expand existing wild life reserves with corridors

N

S

Waste less waterDevelop crops that need less water

Move hazardous material storage tanks away from coast

Prohibit new construction on low-lying coastal areas

Stockpile 1 to 5 year supply of key foods

Expand existing wildlife reserves toward poles

Connect wildlife reserves with corridors

Fig. 18.15, p. 465

Part II: Ozone Depletion

Formation of the Ozone– Photosynthetic, oxygen-producing bacteria created ozone in the

stratosphere about 3.8 million years ago.– 11-16 miles above the Earth’s surface oxygen is continually

converted to ozone by ultraviolet radiation. The reaction is O2 O3 in the presence of sunlight.

– Normally average levels of ozone don’t change. Amount produced is equal to ozone destruction.

– Ozone absorbs 95% of harmful incoming _______________.– 3 types of UV Radiation: A, B, and C. All high level C is absorbed. ½

UVB and some UVA.– Ozone concentrations have been measured since ________– During the 1980s normal ozone levels dropped 40-50 % in winter

above temperate and tropical zones above both hemispheres. Expected to drop 7-13 % during 1990s.

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

UV radiation

Sun

Once 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).

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

Cl

Cl

ClC

F

Cl

Cl

OO

Cl

OO

O

ClO

OO

ClO

O

Summary of ReactionsCCl3F + UV Cl + CCl2FCl + O3 ClO + O2

Cl + O Cl + O2

Repeated many times

Fig. 18.16, p. 466

October monthly means

Year1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

100

150

200

250

300

350

400

Tota

l ozo

ne (D

obso

n un

its)

Fig. 18.17, p. 467

August 7, 1997

October 10, 1997

35

30

25

20

15

10

5

0 5 10 15Ozone partial pressure (milipascals)

Altit

ude

(kilo

met

ers)

Fig. 18.18, p. 467

Year1979 1982 1985 1988 1991 1994 1997 2000 2003 2006

0

5

10

15

20

25

30M

illio

n sq

uare

kilo

met

ers

Fig. 18.19, p. 468

What causes ozone depletion– Group of chemicals called Freons- CFCs- CFC-11

trichlorofluoromethane, and CFC-12, used in refrigerants, propellants, sterilizers, and bubbles in plastic foam. Stable, odorless, non-corrosive, and non-toxic.

– Spray cans, leaky refrigerants and air conditioning equipment release CFCs into the atmosphere. They are chemically inactive and _inert. Through mixing over 20 years they move to stratosphere and release active Cl, which converts O3 to O2.

– Each CFC can last 65-385 years (depending on its type) and convert 100,000molecules of O3 to O2.

– After 15 years (it was discovered to deplete ozone in 1974) finally they banned the use of CFCs.

What causes ozone depletion

– Other chemicals deplete ozone: ozone-depleting compounds= ODCs: carbon tetrachloride, methyl bromide, halons, methyl chloroform. (Found in fire extinguishers, fumigants, solvents, and propellants).

– Measurements and models indicate that 75-85% of the observed ozone losses in the stratosphere since 1976 are the result of ODCs released into the atmosphere by human activities beginning in the 1950s.

Why is thinning of Ozone seasonal?

• In Antarctica ozone thinning as much as 50% occurs in _spring_. During the sunless winter there forms a huge swirling mass of cold air called a polar vortex. It is isolated from the rest of the atmosphere. This traps CFCs over Antarctica. When sun returns in spring then CFCs convert ozone. These ozone “holes” then migrate over _Australia_. This also occurs, but to a lesser extent, in the Arctic.

Antarctic Fig. 18.20a, p. 468

Arctic Fig. 18.20b, p. 468

Why do we care?

– Less Ozone= more biologically damaging ____UV_.

– This means worse sunburns, more cataracts and more __skin cancer__. A 10% loss of global ozone will result in 300,000 additional cases of skin cancer.

• There are more cases of skin cancer _Australia__ than anywhere in the world and cases are increasing in South Africa, Argentine, and Chile

Other effects:• Suppression of __immune system__• Increase in smog• Lower _crop yield_• Decline in forest productivity• Increased breakdown of plastics and

__paints__outdoors• Reduced productivity of phytoplankton

– We can just stay out of the sun, but what about plants and animals, it will cause _ecosystem____ disruption.

What can we do?

• Make substitutes for CFCs:– HCFCs- break down faster, but increase greenhouse gases- no

more after 2020– HC- propane, butane, cheap, can be used c\same as CFCs– Ammonia: refrigerant– Terpenes- citrus based solvent– Helium: refrigerant

NO MORE:– Halons: phased out in 1/1/94– CFCs: phased out in US in spray cans in -1987

everywhere else in 1/1/96– Methyl chloroform: 1/1/96– Methyl bromide: phase out by 2010

What can we do?• -----^ Montreal Protocol of 1981: in 1987 36

nations agreed to cut emissions of CFCs (but not other ozone depleters) by about 35% between 1989 and 2000.

• * Copenhagen Treaty 1992: even more ODCs phased out. Developed countries set aside 250 million dollars to help __developing__ countries. China and India refuse to stop using ODCs. Because of Rush Limbaugh, Dixie Lee Ray and others Congress tried to pull US out of treaties.

•