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Chapter 18: Global Climate Change


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Title: Chapter 18: Global Climate Change

Chapter 18 Global Climate Change
  • area's long-term atmospheric conditions
  • temperature
  • humidity
  • wind
  • precipitation
  • barometric pressure
  • solar radiation
  • global climate change sees all these factors but
    considering the whole planet

Global Warming
  • increase in Earth's average surface temperature

Rate of Atmospheric Changes
  • climate varies naturally overtime
  • the rate has increased
  • fossil fuel combustion and deforestation

Factors that Influence Climate
  • Milankovitch cycles
  • affect intensity of solar radiation
  • cause long-term temperature changes like
  • axial wobble? 19 to 23,000 year cycle
  • variation in tilt? 41,000 year cucle
  • variation in orbit? 100,000 year cycle

Factors that Influence Climate
  • ocean absorption
  • CO2 is soluble in ocean water
  • but as temperature increases solubility decreases
  • phytoplankton absorbs some in photosynthesis
  • but not enough to compensate the extra CO2
    produced today
  • positive feedback effect

Factors that Influence Climate
  • ocean currents
  • El Niño
  • air presure decreases in western Pacific
  • weakens the ecuatorial winds
  • warm water flows east towards America
  • shuts down delivery of nutrients
  • fish population plumbs
  • ocean birds, reptiles and mammals are also
  • causes billions of economical losses

Factors that Influence Climate
  • La Niña
  • opposite of El Niño
  • cold waters extend to the west
  • El Niño/La Niña occur in cycles but these have
    become irregular
  • Scientists are investigating if there is any
    relation between irregularity of phenomena and
    air/water temperature increases

Thermohaline Circulation
Thermohaline Circulation
  • interruption might trigger rapid climate change
  • data suggest circulation is slowing down

Study of Climate Change
  • proxi indicators indirect evidence
  • ice cores
  • tree rings
  • sediment beds
  • coral reef

Study of Climate Change
  • direct atmospheric sampling
  • studies present-day climate
  • measures conditions of the atmosphere
  • concentrations of CO2
  • monitoring of temperature

Study of Climate Change
  • Climate Models
  • simulations
  • mathematical
  • sophisticated computer programs that combine
  • atmospheric circulation
  • ocean circulation
  • atmosphere-ocean interactions
  • feedback
  • old data is used to see if the model works before
    it is applied

Current Climate Change Impacts
  • intenational panel of scientists (IPCC)
  • Fourth Assesment Report of 2007 (fig. 18.12)
  • contains thousands of studies
  • includes some predictions
  • addresses impacts of current and future climate
  • discusses possible strategies

Temperature Increase
  • most of the increase occured in the last few
  • 1995-2006 were among the warmest on record
  • the number of heatwaves have encreased
  • a temperature increase of 0.2ºC is expected per
    decade if there is no control of emissions
  • IPCC predicts that by 2100 temperature will rise
    1.8-4ºC depending on the emission scenario

Temperature Increase
  • Arctic is suffering changes of up to 3ºC
  • ice melts earlier
  • forms later
  • ice area is decreasing
  • thiner ice
  • no food for Inuit people
  • no food for polar bears
  • permafrost is melting

  • Projected Temperature Changes
  • for the decade of 2090-2099

IPPC calculates an increase of 0.1ºC per decade
during the 21st century If we don't control the
emissions it might get to an increase of
4ºC Ocean temperature is also incresing causing
more intense hurricanes
Changes in Precipitation
It is predicted to increase at high latitudes and
decrease at low and middle Will worsen water
shortages near the tropics Away from the tropics
heavy precipitation will become more frequent
increasing chaces of flooding Droughts will
become more severe and frequent
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Melting Ice and Snow
  • risks of sudden floods
  • ice dams burst
  • reduction of summertime water supply
  • Artic/Antartic ice surface is decreasing
  • resulting in larger darker ocean surfaces which
    capture heat and melt the ice faster
  • more dark surfaces on Earth reduces the albedo
    effect (light reflection)
  • as a result Earth's surface increases in
  • positive new shipping lanes and possible sites
    for oil and gas exploration

Rising Sea Levels
Blackwater National Wildlife Refuge in
Maryland marsh loss can occur if the rise is so
fast that plants can't adapt
Rising Sea Levels
  • increase in level worldwide (17cm6.7 in)
  • caused by
  • melting of ice
  • increase in runoff
  • increase in temperature?causes expension of the
    volume of water already there

Problems with Rising Sea Levels
  • beach erosion
  • Florida, Washington, California, Texas, etc.

  • coastal floods
  • Venice, Italy

  • intrusion of salt water into aquifers
  • Los Angeles

  • loss of wetlands (mangroves)

Guayaquil, Ecuador 1985 2000
loss of coal reefs Maldivs possible evacuations
and migration of people Island nations of Tuvalu
and Maldives
  • loss of coral reefs
  • Maldives
  • possible evacuations and migration of people
  • Island nations of Tuvalu and Maldives

Climate Change Effects on Organisms Ecosystems
  • alterations of the environment affect living
  • adaptations take generations to acquire

  • temperature-dependant phenomena have been
    observed and it is attributed to climate change
  • plants blooming timing
  • animals breeding timing
  • birds migration timing
  • insects hatching timing
  • plants and animals are migrating north or higher
  • bleaching of corals

Societal Impacts
  • Agriculture
  • earlier crop planting
  • shift of seasons
  • droughts and floods become more severe
  • predictionssay production may increase but only
  • tropical and subtropical regions will lower
    production due to drought
  • hunger will increase

  • Forestry
  • insect and deiseases are more frequent
  • elm trees
  • invasive species are more common
  • zebra mussle has arrived to Texas (4/09)
  • longer drier fire season
  • El Niño 97-98

Asian longhorned beetle
zebra mussle
zebra mussel
  • Health
  • respiratory diseases
  • more frequent
  • expansion of tropican diseases
  • floods overcoming sewage treatment
  • cholera
  • drowning more probable
  • hunger/ malnurished

Deaths attributed to hot weather
  • Economics
  • people's perception of greenhouse effects has
  • insurance companies began noticing increase in
    weather related disasters
  • industry also changed its point of view
  • An Inconvenient Truth helped spark the interest
  • companies are asking for legislation to require
    significant reduction in greenhouse gas emittions

Responding to Climate Change
  • mitigation or adaptation?
  • mitigation pursue actions that reduce greenhouse
    gas emittions
  • energy efficiency
  • switching to claen renewable energy
  • farm practices that protect soil and water
  • prevent deforestation
  • recovery of gasses from landfills

  • adaptation lessen the impact of future climate
  • seawall in Galveston
  • restricting coastal development
  • adjusting farm practices to drought conditions
  • modification of water management due to water
    conditions (floods, drought and salt intrusion)

Electricity Generation Source of Greenhouse
  • it is the largest source (40) of greenhouse
    gasses in the U.S.
  • 69 of the electricity in the U.S. is generated
    by fossil fuels. 50 is from coal.
  • ways to lessen the amount of fossil fuels used
  • encouraging concervation
  • switching to cleaner and renewable sources

Concervation and Efficiency Saves Money in the
Long Run
  • new technologies
  • high-efficiency light bulbs for example
  • ethical choices
  • EPA's Energy Star Program
  • more efficient electric appliances
  • efficient heating and cooling systems
  • efficient office equipment
  • turn off lights when not in use
  • turn off equipment when not in use

Sources of Electricity Cleaner is Better
  • altering the types of energy we use
  • coal?oil?natural gas
  • natural gas produces half the emissions that coal
  • carbon sequestration (or carbon capture) will
    reduce the CO2 emitted to the air
  • use of OTHER energy sources
  • nuclear power hydroelectric geothermal
  • wind power ocean tides photovoltaic

  • second-largest source of greenhouse gasses
  • 1/3 of the average American city is devoted to
    car use
  • average American family makes 10 trips/day
  • in the U.S. 200 million is spend daily in
    construction and repairs

Typical Automobile is Inefficient
Automotive Technology
  • fuel-efficient vehicles
  • hybrids
  • fully electric
  • alternative fuels (hydrogen cells)

Public Transportation
  • it is a lifestyle choice
  • car use decreases if living near their workplace
  • cities are working on the use of mass transit
  • people are including bike or walk
  • it is not accesible to everyone
  • Arlington refuces to include the train and bus
  • Allen refuces to include the DART train system

Strategies to Reduce Emissions
  • double fuel efficiency in vehicles
  • decrease the miles you drive daily
  • maximize efficiency in buildings
  • double efficiency in coal power plants
  • switch from coal to natural gas
  • capture and store carbon dioxide (sequestration)
  • increase nuclear power production (3x)
  • ?increase wind (50x) solar (700x) energy
  • halt tropical deforestation
  • adopt conservation tillage on croplands

Mandates, Incentives or Both?
  • commandment-and-control policy
  • mandates are often resisted by industry
  • incentives may be more effective
  • whatever desition it has to be
  • fair
  • economically palatable
  • effective
  • enforceable

International Treaties
  • 1992 U.N. Framework Convention on Climate Change-
    voluntary approach
  • by 2006
  • U.S. has increasedits emissions by 17.9
  • Germany decreased its emissions by 17.2
  • U.K. dropped its emissions by 14.3

  • 1997 Kyoto Protocol
  • mandates reduction of emittions to those of 1990
  • reduction must be accoplished by 2008-2012
  • U.S. refused to ratify acusing China and India of
    polluting without having to follow the protocol
  • creating resentment with allies
  • emittions had increased 11 worldwide by 2004

Climate Change Policies from Cities and States
  • in responce to inaction from the G.W. Bush
    administration and Congress
  • "meet or beat" Kyoto Protocol guidelines
  • mayors of 600 cities
  • urging state and federal government to act
  • California passed the Global Warming Solutions
    Act in 2006- 25 reduction of greenhouse gasses
    by 2020
  • cap-and-trade program in the NE

Carbon Offset Key to Mitigating
  • voluntary payment
  • pays the entity that is willing to reduce
    emissions that one in not willing to do
  • becoming very popular
  • carbon-neutrality no net carbon is emitted
  • now it may not be as efficient as thought
  • has to be transparent and enforceable

Carbon Footprint
  • individual everyday life choices
  • reduce the emissions you create
  • transportation
  • EPA Star Program