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Title: Chapters 7, 18.1, 19.1-3


1
Climate, Biodiversity, and Global Climate Change
  • Chapters 7, 18.1, 19.1-3

2
What is climate?
  • Climate an areas general pattern of atmospheric
    conditions over periods of at least 3 decades to
    thousands of years
  • weather averaged over a long period of time, i.e.
    Seattle is always rainy.
  • Able to generalize about the conditions of a
    particular area
  • Conditions determine what organisms can live
    there
  • Weather a set of physical conditions of the
    lower atmosphere such as temperature,
    precipitation, humidity, wind speed, cloud cover
    and other factors in a period of hours or days.
  • what is happening outside right now.

3
Factors that Influence Climate
  • Climate is affected by the distribution of heat
    and precipitation. This is affected by
  • sunlight
  • Air circulation
  • the rotation of the earth
  • ocean currents
  • Over time, patterns of global air circulation and
    ocean currents distribute heat and precipitation
    unevenly between the tropics and other parts of
    the world.

4
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5
Atmospheric Composition
  • What is the atmosphere made of?
  • several layers
  • troposphere, stratosphere, mesosphere,
    thermosphere, exosphere
  • most important for us...the troposphere and
    stratosphere
  • air is more dense closer to earths surface than
    in the upper layers of atmosphere (gravity pulls
    molecules toward earth)
  • Atmospheric pressure

6
the troposphere
  • 70-80 of earths air mass is found here
  • Dense layer closest to earths surface, where all
    weather occurs
  • extends about 11 miles above sea level
  • 99 of the air in this layer consists of nitrogen
    (78) and oxygen (21).
  • The rest is water vapor (varies with humidity),
    argon (.93), carbon dioxide (.039), and trace
    amounts of dust, soot, methane (CH4), ozone (O3),
    and nitrous oxide (N2O).

7
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8
the stratosphere
  • our global sunscreen
  • extends 17-31 miles above the earths surface
  • composition similar to troposphere, with much
    less water vapor and much higher ozone
  • ozone layer (11-16 miles above sea level)
  • keeps 95 of the suns harmful UV radiation from
    reaching earth
  • stratospheric ozone produced when oxygen
    molecules interact with UV radiation from the sun
  • 3 O2 UV ----gt 2 O3

9
  • Global Climate is determined by two major
    factors.
  • 1. global air circulation in the atmosphere
  • This is influenced by
  • Unequal heating of the earths surface (sunlight)
  • Atmospheric convection currents (air circulation)
  • The rotation of the Earth (wind)
  • 2. ocean currents distributing heat in the ocean

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11
Air Circulation Influenced By Uneven Heating
  • at the equator the sun strikes the earth
    directly causing the air to heat more
  • causes tropical regions to be hot and humid
  • Less atmosphere for the sunlight to pass through
    which results in more sunlight per square meter
  • leads to increased evaporation of moisture from
    forests, grasslands, and water bodies---this
    results in more precipitation

12
Air Circulation Influenced By Uneven Heating
  • at the poles the sunlight strikes indirectly,
    causing the heat to disperse
  • causes the polar regions to be cooler
  • Sunlight is more spread out over a larger area
  • More atmosphere to pass through to reach the
    surface (less energy per sq. meter)
  • the regions in between the equator and poles are
    temperate, generally having warm and cool
    temperatures

13
Air Circulation Influenced By Atmospheric
Convection Currents
  • Uneven heating of the earths surface drives the
    circulation of the air
  • Air properties
  • Less dense air rises, dense air sinks
  • warm air risesless dense
  • Warm air has a higher capacity for water vapor
  • humid summer
  • heat from the sun evaporates ocean water and
    transfers heat from ocean to atmosphere
  • creates giant cyclical convection cells that
    circulate air, heat, and moisture (hadley and
    polar cells)

14
Air Circulation Influenced By Atmospheric
Convection Currents
  • Large atmospheric convection currents called
    cells
  • Hadley Cells located near the equator
  • Located between 0 and 30 degrees N and S
  • Polar Cells located near the poles
  • Located between 60 and 90 degrees N and S
  • In between these two cells is an area of air
    circulation by neighboring cells, causes a wide
    range of warm and cold air currents.
  • Where we see influence of the seasons most as the
    earth tilts. (this is where we live)

15
How convection cells form
  • Hadley Cells
  • At the tropics (near the equator) the warming of
    humid air causes it to rise.
  • As the air rises it cools, which produces a
    constant flowing of air upward. The cooling
    causes condensation then precipitation.
  • As the air moves upward into the troposphere, the
    air cools and dries out. It is then displaced
    horizontally by warmer, moister air from below.
  • The cool, dry air sinks at about 30 degrees
    latitude North and South, and as it sinks it
    warms as it approaches the surface.
  • The air then moves back toward the equator, where
    it replaces the rising air, completing the cycle.

16
Deserts
Tropical Rainforests
30 degrees latitude
Equator
17
Air Circulation Influenced By Atmospheric
Convection Currents
  • The place where the two Hadley cells meet at the
    equator is called the intertropical convergence
    zone (ITCZ).
  • Varies with the tilt of the earth, an area where
    earth receives its most intense sunlight.
  • Polar Cells are formed similar to Hadley Cells.
  • Warm air rises near 60 degrees and sinks at the
    poles near 90 degrees. This results in the polar
    areas being very cold and dry.
  • Also helping with atmospheric circulation is
    surface albedo.
  • the reflectivity of a surface (higher in poles
    with snow and ice)

18
  • Global Climate is determined by two major
    factors.
  • 1. global air circulation in the atmosphere
  • This is influenced by
  • Unequal heating of the earths surface (sunlight)
  • Atmospheric convection currents (air circulation)
  • The rotation of the Earth (wind)
  • 2. ocean currents distributing heat in the ocean

19
Air Circulation Influenced By Rotation of the
Earth
  • as the earth spins, the equator moves faster than
    the regions to the north and south
  • this causes heated air masses in the atmosphere
    to rise and move north or south to cooler areas.
    This influences global wind patterns.
  • prevailing winds major surface winds that blow
    continuously to help distribute heat and
    moisture, also to drive ocean currents.
  • Caused by the Coriolis Effecta deflection in an
    objects path as the earth rotates.

20
Air Circulation Influenced By Rotation of the
Earth
  • The prevailing winds are created due to the
    Coriolis effect and atmospheric convection
    currents.
  • As the earth spins, deflected convection currents
    cause the tradewinds, westerlies, and easterlies
    (prevailing winds).
  • Wind moves faster at equator and blows toward
    equator
  • Wind moves slower toward poles and blows away
    from equator.

21
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22
Climate Influenced By Ocean Currents
  • driven by the prevailing winds and the earths
    rotation, the earths major ocean currents help
    redistribute heat from the sun
  • influence climate and vegetation near coasts
  • warm and cold currents circulate around
    continents
  • Clockwise in Northern Hemisphere
  • Counterclockwise in Southern Hemisphere

23
Climate Influenced by Ocean Currents
  • Tropical waters are warm (more sunlight)
  • This warm water expands and rises, which allows
    water to flow away from the equator
  • Shallow warm currents
  • As the current moves away from the equator the
    water cools and sinks
  • Deeper cold currents

24
Biomes
  • The differences in the amount of sunlight, air
    circulation, prevailing winds and ocean currents
    lead to the development of different terrestrial
    biomes around the world.
  • Deserts
  • Tropical desert (Sahara)
  • Temperate desert (Sonoran, AZ)
  • Cold desert (Gobi)
  • Grasslands
  • Savanna
  • Temperate Grassland (prairie)
  • Chaparral
  • Tundra
  • Forests
  • Tropical Rainforest
  • Temperate Deciduous Forest
  • Taiga (Coniferous Forest)

25
Climatogram
26
How much do you spew (CO2)?
  • 1. What impact is this family having on global
    carbon dioxide emissions? Include total lbs in
    your answer.
  • (what you calculated is only 1/3 of their
    emissions) Think about the explanation of their
    lifestyle as well.
  • 2. Less than 11,000 lbs is a good number for CO2
    emissions.
  • What could be done to reduce their emissions?
    What would they need to change as part of their
    lifestyle? Try to alter your scenario to decrease
    the emissions as much as you can.
  • Orwhat is this family doing to have low CO2
    emissions? What is the biggest part of their
    lifestyle that allows them to do this?
  • 3. Are the changes you are suggesting reasonable?
    Or is the lifestyle this family is living
    realistic for everyone? Explain.

27
  • What is climate change?
  • What do you believe is causing climate change?
  • Is this something we can fix? Why or why not?
  • What do you think are some of the effects we
    could see because of a changing climate?

28
Climate Change
  • What is Global Climate Change?
  • Refers to long-term changes in any aspects of the
    earths climate, especially temperature and
    precipitation
  • Global Warming warming of the earths lower
    atmosphere (troposphere), oceans and landmasses
    because of increase in the concentrations of
    greenhouse gases.
  • Results in climate change.

29
Historical Climate Trends
  • Climate has been influenced by suns output of
    energy, meteorite impacts, changes in earths
    orbit, air circulation patterns and human
    activity historically.
  • Earth has had cyclical patterns of warming and
    cooling (glacial and interglacial periods)
  • Historical temperature trends measured through
  • radioactive isotopes in fossils and ocean
    sediments ice cores with bubbles of preserved
    air
  • pollen and tree rings and
  • historical temperature data collected since 1861.
  • Shows general changes in temperature which in
    turn affect climate (not completely exact)

30
Global temperature graphs
31
  • Since temperature data has been recorded 9 of the
    10 hottest years on record occurred between
    2000-2009
  • Globally, temperatures have increased on average
    1.8 degrees Fahrenheit (through 2009)
  • Not evenly distributed around the globesome
    areas significantly warmer and others cooler.
    Some areas had no change.
  • http//www.climatecentral.org/videos/web_features/
    nasa-finds-2011-ninth-warmest-year-on-record

32
Factors Contributing to Climate Change
  • Greenhouse Effect
  • Warming of the lower atmosphere by trapping solar
    energy, which greenhouse gases help radiate back
    to earths surface
  • Greenhouse gases water vapor (H2O), carbon
    dioxide (CO2), methane (CH4), nitrous oxide (N2O)
    and ozone (O3) in troposphere.
  • The earth would be a cold, frozen place without
    this process

33
Greenhouse Effect
34
Greenhouse Gases
  • Natural Sources
  • Volcanic eruptions (CO2)
  • decomposition (CH4 and CO2)
  • digestion (CH4)
  • denitrification (N2O)
  • evaporation (H2O)
  • Anthropogenic (Human) Sources
  • Burning of fossil fuels (CO2 and N2O)
  • deforestation (CO2, CH4 and N2O)
  • agriculture (CH4 and N2O)
  • landfills (CH4)
  • industry (all of the above)

35
Human Impacts
  • Emission of fossil fuels used in industry and to
    generate electricity
  • Emits carbon dioxide (coal burning)
  • As countries become more developed the more
    emissions they have
  • Deforestation
  • Clearing forests eliminate a resource that
    removes CO2 from the atmosphere
  • Agriculture
  • Emission of methane from livestock (CH4)
  • Use of nitrogen fertilizer (nitrous oxides)

36
Factors that affect global warming
  • CO2 emissions
  • Burning of fossil fuels adds CO2 to the
    atmosphere
  • Concentration of CO2 rose from 285ppm in 1850 to
    398ppm in 2010.
  • 450ppm seems to be the tipping point, optimal
    level is around 350ppm
  • Largest emitters of CO2 are China, US, EU,
    Indonesia, Russia, Japan, India
  • US (19) and China (21) account for half of the
    greenhouse gas emissions.

37
Factors that affect global warming
  • Oceans
  • Absorb CO2 from the atmosphere, helps to moderate
    surface temperature
  • Estimated to remove 25-30 of CO2 emitted into
    the atmosphere
  • As air temperature warms so does ocean
    temperature
  • Reduces the ability to absorb CO2
  • Increases acidity as CO2 absorption increases

38
Intergovernmental Panel on Climate Change (IPCC)
  • 2500 climate scientists from more than 130
    countries produce this consensus report on
    climate change at the request of the UN and World
    Meteorological Organization
  • Their findings include
  • Earths lower atmosphere is warming due to
    increased concentrations of carbon dioxide
  • This is due to human activities, which is
    changing the earths climate
  • If greenhouse gas concentration increases, Earth
    likely to experience rapid atmospheric warming
    and climate disruption
  • Likely disrupt food and water supplies, ecosystem
    services, and flood low-lying areas

39
2007 IPCC Report
  • Latest report that includes effects on ecosystems
    and biodiversity. Next report will be published
    in March 2014.
  • Summary of Major Findings.
  • Between 1906 and 2005 global surface temperature
    has risen just over one degree F (most since
    1980)
  • Annual greenhouse gas emissions from human
    activities rose 70 between 1970-2009
  • Glaciers are melting and floating sea ice is
    shrinking.
  • Average sea level rose by about 7 inches

40
2007 IPCC Technical Paper
  • This report was published explaining impacts on
    biodiversity and ecosystems as a result of
    climate change.
  • It also outlines the impacts on humans via food
    sources, living areas and socio-economic
    challenges.
  • Look through the report, facts, diagrams and
    summaries.
  • Highlight any common themes among the effects
    (generalities) that you see.
  • What are the impacts on humans, biodiversity and
    ecosystems as our climate warms up?
  • Make a list (from your highlighting) of the most
    common effects from climate change that we could
    see.

41
Effects of Climate Change
  • Most historic climate changes took place over
    several thousand years.
  • We are now facing a rapid increase in the average
    temperature of the lower atmosphere in this
    century. (climate disruption)

42
Effects of Climate Change
  • Severe Drought
  • Caused by decreased rainfall
  • Growth of trees and other plants declines,
    reducing amount of CO2 taken from atmosphere
  • Wildfires increase
  • Declining streamflows and less available surface
    water, water shortages

43
  • Ice and Snow Melt
  • Climate change most severe in polar regions
    (poles warm faster than other areas)
  • Arctic sea ice disappearing faster than projected
  • Mountain glaciers slowly melting and disappearing
  • Major source of water for rivers
  • Melting Permafrost
  • As this melts releases large amounts of CH4 and
    CO2 into atmosphere
  • Creates positive feedback loop with continued
    global warming.

44
  • Rising Sea Levels
  • Predicted to rise 3-6.5 feet by the end of the
    century, currently they have risen about 9 inches
    since 1870.
  • Due to melting ice, and expansion of water as it
    warms
  • Cause disruption of coastal estuaries, wetlands
    and coral reefs flooding of lowlands, coastal
    cities and islands saltwater contamination of
    groundwater.
  • A sea level rise of just 1.6 feet is estimated to
    affect 150 million people.

45
  • Extreme Weather
  • Severe droughts and heat waves
  • Crop damage
  • Increased flooding, heavy rain or snowfall
  • Increase in hurricanes and tropical storms
  • Biodiversity
  • Loss of biodiversity due to disruption of
    ecosystems
  • Most vulnerable are coral reefs, wetlands,
    tundra, mountaintops
  • Warmer climate increases populations of fungi and
    insects that damage trees and plants

46
  • Agriculture
  • Production will drop in some areas, especially
    those that need specific temperatures/rainfall
  • Production might increase in some areas with
    favorable temperatures
  • Health
  • Increase in death an illnesses with heat waves
  • Increase in pollen, insects, toxic molds and
    other microbes (asthma, allergies)
  • Mosquito-borne diseases more prevalent (malaria,
    yellow fever, dengue fever)
  • Displacement from home (environmental refugees)

47
Solutions to Slow Climate Change
  • Slow and prevent greenhouse gas emissions
  • Improve energy efficiency from all sources
  • Shift to renewable energy sources
  • Decrease/stop deforestation, plant more trees
  • Sustainable agriculture

48
  • Carbon sequestration
  • Removing carbon from atmosphere and storing it
    elsewhere
  • Global tree planting effort
  • Restoring wetlands
  • Plant fast-growing plants which could be used as
    biofuel
  • Carbon capture and storage

49
  • Global treaties, initiatives, or legislation
  • Montreal Protocol (1987) international treaty
    that restricts the use of chemicals that deplete
    the ozone layer.
  • Kyoto Protocol 187 countries ratified this
    agreement to limit greenhouse gas emissions to
    below 1990 levels by 2012. Affects limitations in
    developed countries only.
  • The US never ratified this agreement due to
    exemptions for developing countries, but it was
    signed symbolically by the Clinton Administration
  • Clean Air Act CO2, CH4 and N2O are listed as
    pollutants and should be subject to regulation
  • Carbon/Energy Taxes
  • Cap and Trade Emissions
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