Anthropogenic Sources of Climate Change

(Global Warming)Chapter 23

APES

Anthropogenic Sources of Climate Change

• Two main causes1. Deforestation

2. Increasing Greenhouse Gas levels• Burning Fossil Fuels• Main villain is currently 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

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 burned which releases CO2 – Accounts for 20% of global CO2 emissions

• Deforestation the largest source of emissions in developing countries

Greenhouse Greenhouse EffectEffect

Greenhouse EffectGreenhouse Effect• Certain 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 Global WarmingWarming

Evidence of Global Evidence of Global WarmingWarming

• COCO22 and Temperature and Temperature

Mauna Loa Study

• Study air chemistry in remote location in Hawaii from 1950’s to present

• Showed annual fluctuations in CO2 btwn winter & summer (why it looks like a zig-zag)

• Also a steady CO2 increase from 315 ppm by volume in 1958 to 370 ppm in 1999.

• This graph has been on almost every APES test!!!

Five Warmest Years on Five Warmest Years on RecordRecord1.1. 20052005

2.2. 19981998

3.3. 20022002

4.4. 20032003

5.5. 20042004

Since 1980, the Earth has experienced 19 of its Since 1980, the Earth has experienced 19 of its 20 hottest years on record20 hottest years on record

EvidenceEvidence• CO2 and Temperature

• GlaciersGlaciers

GlaciersGlaciers• Have been shrinking throughout the

20th Century• Loss of glaciers in South America and

Asia is particularly rapid and will threaten the water supplies of millions of people

• http://www.cnn.com/2007/TECH/science/11/26/andes.water.ap/index.html

EvidenceEvidence• CO2 and Temperature

• Glaciers

• Polar IcePolar Ice– Arctic

– Antarctic

– Greenland

Arctic IceArctic Ice

Arctic IceArctic Ice• Perennial 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

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

NEWS RELEASE: September 13, 2006

• From 1970 until 2000 there was a 10 percent decrease in Arctic perennial sea ice every decade

• Between 2004 and 2005 the ice shrunk abruptly by 14 percent14 percent

PermafrostPermafrost

PermafrostPermafrost

• Where soil over 1-meter down never thaws• About 10% of Earth’s surface has permafrost• Tundra 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

PermafrostPermafrost• Alaska permafrost

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

• Serious effects include – sinking roads and buildings– eroding tundra riverbanks– changes in tundra

vegetation– increased carbon dioxide

and methane emissions from thawed peat.

PermafrostPermafrost• Estimates of billions

of tons of methane – Will double existing

methane in atmosphere

• Methane is 20 to 60 times as strong of a greenhouse gas as CO2

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 glacier

• Bring melted water below the glaciers

• Can cause glaciers to slip off bedrock into ocean

Series of Series of MoulinsMoulins

Antarctica MeltingAntarctica Melting

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

the oceans will risethe oceans will rise

200 feet200 feet

Greenland IceGreenland Ice

Greenland Ice Greenland Ice MeltMelt

• 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…

• http://www.cnn.com/SPECIALS/2007/planet.in.peril/greenland.html

EvidenceEvidence• CO2 and Temperature

• Glaciers

• Polar Ice– Arctic

– Antarctic

– Greenland

• Weather SeverityWeather Severity

DroughtsDroughts• The 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 three most extensive droughts in the last 40 yearsyears

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

• 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 Temperature

• Glaciers

• Polar Ice– Arctic– Antarctic– Greenland

• Weather SeverityWeather Severity

• Biome ChangesBiome Changes

Oceans absorb COOceans absorb CO22

• CO2 in water makes Carbonic Acid

• Increased CO2 especially in cold water

• As cold deep ocean currents (abyssal) resurface they release CO2

• Greater acidity of oceans is bleaching coral

ConsequencesConsequencesof Global Climate of Global Climate

ChangeChange

ConsequenceConsequence• Cold EuropeCold Europe

Arctic Water lower Arctic Water lower SalinitySalinity

Thermohaline Thermohaline CirculationCirculation

• Half Century of measurements by Britain's National Oceanography Centre– Suggest a noticeable slowing (30%)

– Due to Arctic and Greenland ice melting

ConsequenceConsequence• Cold Europe

• Increased SmogIncreased Smog

ConsequenceConsequence• Cold Europe

• Increased Smog

• Spread of Tropical DiseaseSpread of Tropical Diseases

ConsequenceConsequence• Cold Europe

• Increased Smog

• Spread of Tropical Diseases

• Changes in BiodiversityChanges in Biodiversity

Changes in Changes in BiodiversityBiodiversity

"It is not the strongest of the species that survive, nor the most intelligent, but the most

responsive to change."

Charles Darwin, 1835

Changes in Changes in BiodiversityBiodiversity

Biomes Shift of Alpine biomes up mountains and

further North/South

Changes in Changes in BiodiversityBiodiversity

Die-offsCoral bleaching die-offs of up to 50% in the

Indian Ocean

Biomes Shift of Alpine biomes up mountains and

further North/South

Dire prediction for Dire prediction for world's coral reefsworld's coral reefs

POSTED: 1404 GMT (2204 HKT), October 25, 2006 CHARLOTTE AMALIE, U.S. Virgin Islands (AP)

Researchers fear more than half the world's coral reefs could die in less than 25 years and say global warming may at least be partly to blame.Sea temperatures are rising, weakening the reefs' resistance to increased pollutants, such as runoff from construction sites and toxins from boat paints. The fragile reefs are hosts to countless marine plants and animals."Think of it as a high school chemistry class," said Billy Causey, the Caribbean and Gulf Mexico director of the National Oceanic and Atmospheric Administration."You mix some chemicals together and nothing happens. You crank up the Bunsen burner and all of a sudden things start bubbling around. That's what's happening. That global Bunsen burner is cranking up."Causey was one of some 200 private and government researchers from the Caribbean, Florida and U.S. Pacific islands who gathered in St. Thomas for a meeting of the NOAA's U.S. Coral Reef Task Force.Last year's coral loss in the Caribbean waters supports predictions that 60 percent of the world's coral could die within a quarter century, said Tyler Smith of the University of the Virgin Islands."Given current rates of degradation of reef habitats, this is a plausible prediction," Smith said.More than 47 percent of the coral in underwater study sites covering 31 acres around the U.S. Virgin Islands died after sea temperatures exceeded the norm for three months in 2005, said Jeff Miller, a scientist with the Virgin Islands National Park.The unusual warm water can stress coral, causing it to lose its pigment and making it more vulnerable to disease.This year, Caribbean coral narrowly avoided another widespread episode of bleaching when sea temperatures briefly surpassed levels considered healthy for reefs.Up to 30 percent of the world's coral reefs have died in the last 50 years, and another 30 percent are severely damaged, said Smith, who studies coral health in the U.S. Virgin Islands and collaborates with researchers globally."U.S. Virgin Islands coral today is likely at its lowest levels in recorded history," Smith said.The researchers said global warming was a potential cause of the abnormally high sea temperatures but was not the only suspect in the reefs' demise.What causes disease in coral can be hard to pinpoint and could be a combination of things. Other threats include silt runoff from construction sites, which prevents the coral from getting enough sunlight, and a record increase in fleshy, green algae, which competes with coral for sunlight."Climate change is an important factor that is influencing coral reefs worldwide," said Mark Eakin, director of NOAA's Coral Reef Watch. "It adds to the other problems that we are having."

Changes in Changes in BiodiversityBiodiversity

Die-offs

Extinctions

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

Golden Toads, Harlequin Frogs, ...

Biomes Shift of Alpine biomes up mountains and

further North/South

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

Hannah Hoag for National Geographic News November 28, 2006

• In Costa Rica about two-thirds of the 110 known harlequin frog species are extinct

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

Changes in Changes in BiodiversityBiodiversity

Die-offs

Extinctions

Life Cycles

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

Golden Toads, Harlequin Frogs, ...

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

Biomes Shift of Alpine biomes up mountains and

further North/South

Life Cycle ChangesLife Cycle Changes• Marmots in the area now emerge from

hibernation about a month earlier than they did 30 years ago

• During the same period, the average April low temperature in Crested Butte rose 5.9 degrees

Changes in Changes in BiodiversityBiodiversity

Die-offs

Extinctions

Life Cycles

Physiology

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

Golden Toads, Harlequin Frogs, ...

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

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

over the last 25 years

Biomes Shift of Alpine biomes up mountains and

further North/South

Global Warming Already Global Warming Already Causing Extinctions, Causing Extinctions,

Scientists SayScientists SayHannah Hoag for National Geographic News November 28, 2006

• Polar bears depend on ice

• Without the ice, the polar bear will die

Changes in Changes in BiodiversityBiodiversity

Die-offs

Extinctions

Life Cycles

Physiology

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

Golden Toads, Harlequin Frogs, ...

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

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

over the last 25 years

Biomes Shift of Alpine biomes up mountains and

further North/South

Migration Multiple areas affected

Migratory Species as Migratory Species as IndicatorsIndicators

• Effects of climate change on the behaviour on migratory species are becoming increasingly evident.

• Although migration is itself a flexible reaction to ecological conditions, migratory species seem more vulnerable than most wildlife as they use multiple habitats and sites and a wide range of resources through their migratory cycle.

• www.cms.int/news/current_news_page.htm

Routes farther North & Routes farther North & Wind BarriersWind BarriersEuropean Bee-Eaters (Merops apiaster) once very

rare in Germany are now breeding regularly across the country.

The Rosy-Breasted Trumpeter Finch (Rhodopechys githaginea) is one of many birds once normally confined to arid North Africa and the Middle East now found in increasingly large numbers in southern Spain.

Bewick’s SwanBewick’s Swan

The arrival of hundreds of Bewick Swans (Cygnus columbianus) flying in distinctive “V” formations used to herald the arrival of the British winter; ornithologists now report numbers down to double figures.

Habitat ChangesHabitat ChangesAlien species like the Pacific Oyster brought to Europe for commercial reasons used not to be able to survive outside artificial pens. As the North Sea has grown warmer, the Pacific oyster has been able to breed in the wild and is now displacing native oysters in the Wadden Sea.Incidence of flooding and resultant sediment run-off in Queensland, Australia damaged seagrass pasture leading to reduced growth and breeding rates for Green turtles

Baffin Bay hosts the largest concentrations of wintering Narwhals Here the trend has been for increased ice coverage in winter. The Narwhals depend on cracks in the ice to breathe and there have been several occasions when they have become trapped in the ice. Their site fidelity and the decrease in open water make them susceptible to Climate Change.

FeedingFeedingAs migratory species are affected by climate change, then so are their prey species. For example, reproductive success of the non-migratory Great Tit and migratory Pied Flycatcher is being affected by the changing availability of caterpillar food supplies. The temporal mismatch of prey and predator is part of a phenomenon known as “phenological disjunction”.

Reduced oceanic salinity causes shifts in the distribution of biomass constituents of the food chain with a tendency for poleward shifts in species assemblages and the potential loss of some polar specialist species like the Narwhal.

It is doubtful whether Polar Bears will be able to adapt fast enough to changing ice conditions affecting the habitat of their seal prey species, and the disappearance of the ice threatens the bears’ survival.

FeedingFeedingKrill may be outcompeted by other species more tolerant of warmer water

with repercussions for species higher up the food chain

ConsequenceConsequence• Cold Europe

• Increased Smog

• Spread of Tropical Diseases

• Changes in Biodiversity

• Droughts and firesDroughts and fires

Climate change has upset rainfall Climate change has upset rainfall patterns and caused severe drought and patterns and caused severe drought and

desertification in the areadesertification in the area

Tuareg & Wodaabe Tuareg & Wodaabe HerdersHerders

ConsequenceConsequence• Cold Europe

• Increased Smog

• Spread of Tropical Diseases

• Changes in Biodiversity

• Droughts and fires

• Sea levels riseSea levels rise

total melting would raise ocean level 75m

Florida Florida during Ice Ageduring Ice Age - 20,000 years ago (400 feet below today) - 20,000 years ago (400 feet below today)

Florida – if West sheet or Greenland melted (17-foot rise) Florida – if West sheet or Greenland melted (17-foot rise)

Florida – if East sheet melted (170-foot/50m rise)Florida – if East sheet melted (170-foot/50m rise)

Positive FeedbackPositive Feedback

Positive FeedbackPositive Feedback• Oceans currents and CO2 levels

– Cold deep resurface and emit CO2

– Warmer oceans do not take up CO2 and actually emit more CO2.

• Permafrost melting– CO2 and methane released by decomposition

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

up• Desertification

– Soil dries out and releases CO2

Why do Why do WEWE need to need to Reduce?Reduce?

• Global Warming is a factGlobal Warming is a fact– Natural Natural – Man-madeMan-made– Both????Both????

• China and India will soon surpass China and India will soon surpass U.S.A. in Greenhouse gas emissionU.S.A. in Greenhouse gas emission

• If we do nothing, they will continue to If we do nothing, they will continue to do nothing (do nothing (The EconomistThe Economist 9/9/06) 9/9/06)

What can we do?What can we do?

• Build GreenBuild Green

• Reduce use of electricity from Reduce use of electricity from fossil fuelsfossil fuels

• Hydrogen powered vehiclesHydrogen powered vehicles

• Invest in green companiesInvest in green companies

• Reduce meat consumptionReduce meat consumption

Cattle and MethaneCattle and Methane

• Cattle and other ruminant animals –Methane is by-product of digestion

• Organisms in their stomachs break down fiber in grasses and grains they eat

EnvironmentalEnvironmental Protection Protection AgencyAgency

Methane Source 2003

Fossil Fuel Production 37.6 %

Cattle 28.3 %

Landfills and Wastewater Treatment

30.8 %

Other 3.3 %

Total for U.S. 100 %

Methane is 20 to Methane is 20 to 60 times as 60 times as strong of a strong of a

greenhouse gas greenhouse gas as COas CO22

What can we do?What can we do?

• Build GreenBuild Green

• Reduce use of electricity from Reduce use of electricity from fossil fuelsfossil fuels

• Hydrogen powered vehiclesHydrogen powered vehicles

• Invest in green companiesInvest in green companies

• Reduce meat consumptionReduce meat consumption

• Carbon sequestrationCarbon sequestration

Carbon SequestrationCarbon Sequestrationhttp://sequestration.mit.edu/technology_overview/index.html

• Two primary types of carbon sequestration. • Carbon dioxide capture and storage

– carbon dioxide is captured at its source (e.g., power plants, industrial processes)

– subsequently stored in non-atmospheric reservoirs (e.g., depleted oil and gas reservoirs, unmineable coal seams, deep saline formations, deep ocean).

• Enhancing natural processes (e.g., forestation). • What about seeding the ocean with iron to promote algal

growth which will then absorb CO2 from air? What are the pros and cons of this? Read articles on Bb to find out!

• [Encyclopedia of Energy (2004)].

Carbon SequestrationCarbon Sequestrationhttp://sequestration.mit.edu/technology_overview/index.html

The Sleipner project in Norway's North Sea is the world's first commercial carbon dioxide capture and storage projectStarted in 1996, it sequesters about one million metric tons of carbon dioxide each year http://www.statoil.com/STATOILCOM/SVG00990.NSF/web/sleipneren?opendocument

What can we do?What can we do?• Build GreenBuild Green• Reduce use of electricity from fossil Reduce use of electricity from fossil

fuelsfuels• Hydrogen powered vehiclesHydrogen powered vehicles• Invest in green companiesInvest in green companies• Reduce meat consumptionReduce meat consumption• Carbon sequestrationCarbon sequestration• Encourage ratification of Kyoto Encourage ratification of Kyoto

ProtocolProtocol

Cutting Emissions

• Earth Summit 1992- Rio de Janeiro– Return greenhouse gas concentrations to 1990

conditions by 2000– Only Fiji ratified this treaty

• Kyoto Protocol 1997- Kyoto Japan– 160 countries finally agreed on a

new treaty – Roll back CO2, methane, &

nitrous oxide emissions by 5% below 1990 conditions by 2012

– US lobbied to have emissions treated as commodities for trading, banking, and borrowing.

– Developing countries were exempt from emission limits

• Earth Summit 2002- Johannesburg– It covered everything from measures to cut poverty,

improve sanitation, improve ecosystems, reduce pollution, and improve energy supply for poor people.

– Boycotted by US Government

Intergovernmental Panel on Climate Change (IPCC)

• http://www.ipcc.ch/ipccreports/ar4-syr.htm• United Nations sponsored working group of

2400 scientists studied human caused sources of climate change.

• Important conclusions:– World climate has changed significantly over the past

century– The balance of evidence suggests a discernible

human influence on global climate– Climate models suggest that if current trends

continue, global mean surface air temp will increase btwn 1ºC and 4.5ºC by 2100

What do the skeptics say?(remember… these are skeptics)

• CO2 less potent than thought• Methane levels declining• Models should be predicting more warming

should be occurring but its not• If temp increases, more clouds form, raise

earth’s albedo, atmosphere should cool• Excess CO2 stimulates plant growth• We are lucky to have CO2 otherwise we

would be on our way to new ice age.