Climate Change and Ozone LossClimate Change and Ozone Loss

G. Tyler Miller’sLiving in the Environment

14th Edition

Chapter 21

G. Tyler Miller’sLiving in the Environment

14th Edition

Chapter 21

Key ConceptsKey Concepts

Changes in Earth’s climate over time Changes in Earth’s climate over time

Factors affecting climate Factors affecting climate

Possible effects of global warming Possible effects of global warming

Adapting to climate change Adapting to climate change

Human impacts on the ozone layer Human impacts on the ozone layer

Protecting and restoring the ozone layer Protecting and restoring the ozone layer

Average temperature over past 900,000 years

Thousands of years ago

Ave

rag

e su

rfac

e te

mp

erat

ure

(°C

)

900 800 700 600 500 400 300 200 100 Present9

10

11

12

13

14

15

16

17

Past Climate Changes

Temperature change over past 22,000 years

Years ago

Tem

per

atu

re c

han

ge

(°C

)

20,000 10,000 2,000 1,000 200 100 Now

-5

-4

-3

-2

-1

0

1

2

End oflast iceage

Agriculture established

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

Past Climate Changes

Temperature change over past 1,000 years

Year

Tem

per

atu

re c

han

ge

(°C

)

1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2101

-1.0

-0.5

0.0

0.5

1.0

Average temperature over past 130 years

Year

Ave

rag

e su

rfac

e te

mp

erat

ure

(°C

)

1860 1880 1900 1920 1940 1960 1980 2000 2020

13.6

13.8

14.0

14.2

14.4

14.6

14.8

15.0

Recent trends in global temperatures

IPCC

1988 UN and the World Meteorological Organization established the (IPCC) Intergovernmental Panel on Climate Change to document past climate change and project future climate change.

A network of over 2,000 leading climate experts from 70 nations.

Table 21-1Page 464

Table 21-1 Major Greenhouse Gases from Human Activities

Greenhouse Gas

Carbon dioxide (CO2)

Methane (CH4)

Nitrous oxide (N2O)

Chlorofluorocarbons(CFCs)*

Hydrochloro-fluorocarbons (HCFCs)

Hydrofluorocarbons(HFCs)

Halons

Carbon tetrachloride

Average Time in the Troposphere

100–120 years

12–18 years

114–120 years

11–20 years (65–110 years in stratosphere)

9–390

15–390

65

42

Human Sources

Fossil fuel burning, especially coal (70–75%), deforestation, and plant burning

Rice paddies, guts of cattle and termites, landfills, coal production, coal seams, and natural gas leaks from oil and gas production and pipelines

Fossil fuel burning, fertilizers, livestock wastes, and nylon production

Air conditioners, refrigerators, plastic foams

Air conditioners, refrigerators, plastic foams

Air conditioners, refrigerators, plastic foams

Fire extinguishers

Cleaning solvent

Relative Warming Potential (compared to CO2)

1

23

296

900–8,300

470–2,000

130–12,700

5,500

1,400

The Greenhouse EffectThe Greenhouse Effect

Fig. 6-14 p. 110

Climate Change and Human Activities

Increased use of fossil fuelsIncreased use of fossil fuels

Deforestation Deforestation

Global warmingGlobal warming

Melting icecaps and glaciersMelting icecaps and glaciers

Rising sea levelRising sea level

Global WarmingGlobal Warming

Svante Arrhenius first speculated in 19th centuryCurrent Causes Deforestation Greenhouse Gas Levels

Burning of Fossil FuelsMain villain is currently Carbon Dioxide

(CO2)

DeforestationDeforestation

Deforestation - USDeforestation - US

About one half of the forests that covered the Earth are gone

Since 1600, 90% of the U.S. forests have been cleared away

Deforestation - RainforestsDeforestation - Rainforests

One football field of rainforest is lost every 1.4

seconds

Results of Results of DeforestationDeforestation

Loss of trees’ ability to remove CO2

Decaying trees release CO2 and methane 25% of global GHG emissions

Fallen trees are often burnt which releases CO2 Accounts for 20% of global CO2 emissions

Deforestation the largest source of emissions in developing countries

Greenhouse Greenhouse EffectEffect

Greenhouse EffectGreenhouse EffectCertain gases in the Earth’s atmosphere trap energy from the sun carbon dioxide – water vapor methane – nitrous oxide

Without these gases, the Earth’s average temperature would be about 60ºF colder

These gases are Greenhouse GasesGreenhouse Gases

Global WarmingGlobal Warming

EvidenceEvidence

COCO22 and Temperature and Temperature

Five Warmest Years on Five Warmest Years on RecordRecord

1.1. 20052005

2.2. 19981998

3.3. 20022002

4.4. 20032003

5.5. 20062006

Since 1980, the Earth has experienced 19 of its 20 Since 1980, the Earth has experienced 19 of its 20 hottest years on recordhottest years on record

EvidenceEvidence

CO2 and Temperature

GlaciersGlaciers

Portage Glacier- near Anchorage Alaska- 1950/2001

Rhone glacier in the Kanton of Valais, Switzerland 1859 / 2001

Grinnell glacier, Glacier National Park, USA 1911 / 2000

Glacier Ururashraju, at about 15,000 feet in Cordillera Blanca of Peru 1986 / 1999

20042004

GlaciersGlaciers

Have been shrinking throughout the 20th Century

Loss of glaciers in South America and Asia glaciers is particularly rapid and will threaten the water supplies of millions of people

EvidenceEvidence

CO2 and Temperature

Glaciers

Polar IcePolar Ice Arctic Antarctic Greenland

Arctic IceArctic Ice

Arctic IceArctic IcePerennial ice may be 10 or more feet thick

New ice is only one to seven feet thick

Since 1970 10% loss of ice cover per decade

Albedo EffectAlbedo Effect

Albedo, or reflectivity

Fig. 21-17 p. 480 Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14Slide 14

Oceans 5%

Bare sand 30–60%

Grass 15–25%

Clouds 50–55%

Snow 80–90%

City 10–15%

Forest 5%

Figure 21-7Page 468

NASA Sees Rapid Changes in NASA Sees Rapid Changes in Arctic Sea IceArctic Sea Ice

NEWS RELEASE: September 13, 2006

From 1970 until 2000 there was a 10 percent decrease in Arctic perennial sea ice every decadeBetween 2004 and 2005 the ice shrunk abruptly by 14 percent14 percent

PermafrostPermafrost

PermafrostPermafrostWhere soil over 1-meter down never thawsAbout 10% of Earth’s surface has permafrostTundra and taiga are characterized by extreme cold 24 hours of sun during the summer Huge amount of vegetation grows

In the last 11,000 years, the permafrost has not thawed None of the vegetation has decayed Decay releases CO2 and methane

PermafrostPermafrostAlaska permafrost temperature has increased 0.5° to 1.5° C since 1980, Serious effects include forest damage sinking roads and buildings eroding tundra riverbanks changes in tundra vegetation increased carbon dioxide and

methane emissions from thawed peat.

PermafrostPermafrostEstimates of billions of tons of methane Double existing

methane in atmosphereMethane is 20 to 60 times as strong of a greenhouse gas as CO2 10 to 25% increase in

global warming

Antarctic IceAntarctic Ice

AntarticaAntartica

Land mass covered by multiple glaciers

Glaciers average 8000 feet thick

Represents 10% of all landmass on Earth

MoulinsMoulins

Rivers of water about 10 meters in diameter that flow through the glacierBring melted water below the glaciers

Series of Series of MoulinsMoulins

Antarctica MeltingAntarctica Melting

If all of the ice in the glaciers If all of the ice in the glaciers of Antarctica melt the oceans of Antarctica melt the oceans

will risewill rise

200 feet200 feet

Greenland IceGreenland Ice

Greenland Ice MeltGreenland Ice Melt

Glaciers located on three islands

Greenland loses 20% more ice than it gains each year

If all of the ice melts – oceans will rise 23 feet

If moulins work like those in Antarctica…

EvidenceEvidence

CO2 and TemperatureGlaciersPolar Ice Arctic Antarctic Greenland

Weather SeverityWeather Severity

DroughtsDroughtsThe 1999-2002 national drought was one of the The 1999-2002 national drought was one of the three most extensive droughts in the last 40 yearsthree most extensive droughts in the last 40 years

In 2002, the Western United States experienced its In 2002, the Western United States experienced its second worst wildfire season in the last 50 years; second worst wildfire season in the last 50 years; more than 7 million acres burnedmore than 7 million acres burned

The period from April through June of 1998 was The period from April through June of 1998 was the driest three-month period in 104 years in the driest three-month period in 104 years in Florida, Texas, and LouisianaFlorida, Texas, and Louisiana

EvidenceEvidence

CO2 and TemperatureGlaciersPolar Ice Arctic Antarctic Greenland

Weather SeverityBiome ChangesBiome Changes

Oceans absorb COOceans absorb CO22

CO2 in water makes Carbonic Acid

Increased CO2 especially in cold waterAs cold deep ocean currents (abyssal) resurface they are release CO2

Greater acidity of oceans is one of the factors that effect bleaching coral