1 global warming…what is it? global warming refers to an average increase in the earth's...

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Global Warming…What is it?Global Warming…What is it?

Global Warming refers to an average increase in Global Warming refers to an average increase in the Earth's temperature,the Earth's temperature,– Climate changeClimate change– Caused by the GREENHOUSE EFFECTCaused by the GREENHOUSE EFFECT

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Greenhouse GasesGreenhouse Gases

The greenhouse gases contribute to holding heat inside The greenhouse gases contribute to holding heat inside our atmosphere.our atmosphere.

They include:They include:– carbon dioxide (COcarbon dioxide (CO22))– methane (CHmethane (CH44))– nitrous oxide (Nnitrous oxide (N22O)O)– chlorofluorocarbons (CFCs)chlorofluorocarbons (CFCs)– ozone (Oozone (O33) ) – water vaporwater vapor

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Global Warming• Current Causes

– Deforestation

– Greenhouse Gases• Burning of Fossil Fuels

• Main villain is currently Carbon Dioxide (CO2)

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Deforestation - USDeforestation - US• About ½ half of About ½ half of

the forests are the forests are gone gone

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

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Results of DeforestationResults of Deforestation• No CO2 removal • Decaying trees • Fallen trees are often burnt• Largest source of emissions in developing

countries

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Current EvidenceCurrent Evidence

COCO2 2 and temperatureand temperature

– Measured by analyzing radioisotopes in rocks, Measured by analyzing radioisotopes in rocks, fossils, ocean sediments, ice coresfossils, ocean sediments, ice cores

11http://web.mit.edu/12.000/www/m2011/finalwebsite/graphics/climate/tempmap1.png

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EvidenceEvidence COCO22 and Temperature and Temperature

GlaciersGlaciers

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GlaciersGlaciers• Have been shrinking throughout the Have been shrinking throughout the

20th Century20th Century• Why is this a problem?Why is this a problem?

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GlaciersGlaciers Polar IcePolar Ice

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Arctic Ice• Perennial ice may be 10 or more feet thick

• New ice is only one to seven feet thick

• Since 1970 a 10% loss of ice cover per decade

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Energy and the Greenhouse Energy and the Greenhouse EffectEffect

Surfaces that reflect energy have a highSurfaces that reflect energy have a high albedoalbedo..– Fresh clean snow Fresh clean snow 90% 90%– Dark soil Dark soil 3%3%– Net average of earth Net average of earth 30%30%

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Albedo EffectAlbedo Effect

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PermafrostPermafrost• About 10% of Earth’s surface has permafrostAbout 10% of Earth’s surface has permafrost

• In the last 11,000 years, the permafrost has In the last 11,000 years, the permafrost has not thawed not thawed – None None of the vegetation has decayedof the vegetation has decayed

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PermafrostPermafrost• Alaska permafrost Alaska permafrost

temperature has increased temperature has increased 0.5° to 1.5° C since 1980, 0.5° to 1.5° C since 1980,

• Serious effects include Serious effects include – forest damageforest damage– sinking roads and buildingssinking roads and buildings– eroding tundra riverbankseroding tundra riverbanks– changes in tundra changes in tundra

vegetationvegetation– increased carbon dioxide increased carbon dioxide

and methane emissionsand methane emissions

24http://benmuse.typepad.com/ben_muse/images/2007/10/10/sinkhole_5.png

25http://www.global-greenhouse-warming.com/images/PermafrostDrunkenForest.jpg

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PermafrostPermafrost• A University of Alaska at A University of Alaska at

Fairbanks team found that the Fairbanks team found that the permafrost gave off 5X as permafrost gave off 5X as much methane as previously much methane as previously estimated estimated

• Defrosting could release nearly Defrosting could release nearly 1,000 gigatons of carbon stored 1,000 gigatons of carbon stored and hasten global warming. and hasten global warming. • Problem?Problem?

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GlaciersGlaciers Polar IcePolar Ice Weather SeverityWeather Severity

– Droughts, hurricanes, tropical stormsDroughts, hurricanes, tropical storms

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EvidenceEvidence• COCO22 and Temperature and Temperature

• GlaciersGlaciers

• Polar IcePolar Ice

• Weather SeverityWeather Severity

• Biome ChangesBiome Changes

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Oceans absorb COOceans absorb CO22

• COCO22 in water makes in water makes

Carbonic AcidCarbonic Acid

• Greater acidity of oceans is Greater acidity of oceans is bleaching coralbleaching coral

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ConsequenceConsequence• Cold EuropeCold Europe

• Increased melting from Greenland could dilute Increased melting from Greenland could dilute ocean water and stop the water from sinking near ocean water and stop the water from sinking near Greenland and shut down the mixing of the Greenland and shut down the mixing of the waterswaters

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Antarctica

Cold water melting fromAntarctica's ice cap and

icebergs falls to the ocean floor and surges northward, affecting

worldwide circulation.

Cold water melting fromAntarctica's ice cap and

icebergs falls to the ocean floor and surges northward, affecting

worldwide circulation.

GreenlandGreenland

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ConsequenceConsequence• Cold Europe Cold Europe

• Increased SmogIncreased Smog

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• Spread of Tropical DiseaseSpread of Tropical Diseasess

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• Spread of Tropical DiseasesSpread of Tropical Diseases

• Changes in BiodiversityChanges in Biodiversity

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Changes in BiodiversityChanges in BiodiversityBiomes

Shift of Alpine biomes up mountains and further North/South

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Changes in BiodiversityChanges in Biodiversity

Die-offs Coral bleaching die-offs of up to 50% in the Indian Ocean

Biomes Shift of Alpine biomes up mountains and

further North/South

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Die-offs

Extinctions

Coral bleaching die-offs of up to 50% in the Indian Ocean

Golden Toads, Harlequin Frogs, ...


further North/South

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Global Warming Already Causing Global Warming Already Causing Extinctions, Scientists SayExtinctions, Scientists Say

Hannah Hoag for Hannah Hoag for National Geographic NewsNational Geographic News November 28, 2006 November 28, 2006

• In Costa Rica about 2/3 of the 110 known In Costa Rica about 2/3 of the 110 known Harlequin frog species are extinctHarlequin frog species are extinct

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Global Warming Already Causing Global Warming Already Causing Extinctions, Scientists SayExtinctions, Scientists Say

Hannah Hoag for Hannah Hoag for National Geographic NewsNational Geographic News November 28, 2006 November 28, 2006

• In Antarctica, the Adélie penguin on Litchfield In Antarctica, the Adélie penguin on Litchfield Island has disappeared. Island has disappeared.

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Die-offs

Extinctions

Life Cycles



Gothic marmots emerge from hibernation about a month earlier than 30 years ago


further North/South

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Die-offs

Extinctions

Life Cycles

Physiology




The average weight of adult female polar bears has decreased by more than 20% over

the last 25 years


further North/South

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Die-offs

Extinctions

Life Cycles

Physiology




The average weight of adult female polar bears has decreased by more than 20% over

the last 25 years


further North/South

Migration Multiple areas affected

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Routes farther NorthRoutes farther North

European Bee-Eaters

•once very rare in Germany

•now breeding throughout

The Rosy-Breasted Trumpeter Finch

•Normal range: arid North Africa and the Middle East

•Extended range: large numbers in southern Spain.

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Habitat ChangesHabitat ChangesPermafrost is thawing and Arctic tundra is being replaced by forest

Desertification is occurring in Africa

Sea levels are rising

Hurricanes are more frequent in the Caribbean

Antarctic waters are getting warmer and the ice is melting affecting sea salinity

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Habitat ChangesHabitat Changes

There is likely to be a general shift of species towards the poles, reducing the range of species most adapted to colder waters.

The Common Dolphin, a warm water species is increasing its range

The White-beaked Dolphin’s range is reducing.

Predators are following their prey as prey species (ex. fish) change their mean latitude and/or depth.

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• Droughts and firesDroughts and fires

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• Droughts and firesDroughts and fires

• Sea levels riseSea levels rise

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Positive FeedbackPositive Feedback• Oceans currents and COOceans currents and CO22 levels levels

– Cold deep resurface and emit COCold deep resurface and emit CO22

• Permafrost meltingPermafrost melting– COCO22 and methane released by decomposition and methane released by decomposition

• Arctic ice meltingArctic ice melting– Less reflection of sunlight – water and land Less reflection of sunlight – water and land

heat upheat up

• DesertificationDesertification– Soil dries out and releases COSoil dries out and releases CO22

1 global warming…what is it? global warming refers to an average increase in the earth's...

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