Chapters 7, 18.1, 19.1-3

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Climate, Biodiversity, and Global Climate Change

• Chapters 7, 18.1, 19.1-3

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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.

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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.

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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

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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).

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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

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• 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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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

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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

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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)

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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)

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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.

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Deserts
Tropical Rainforests
30 degrees latitude
Equator
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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)

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• 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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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.

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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.

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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

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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

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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)

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Climatogram
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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.

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• 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?

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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.

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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)

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Global temperature graphs
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• 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

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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

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Greenhouse Effect
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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)

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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)

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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.

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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

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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

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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

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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.

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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)

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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

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• 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.

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• 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.

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• 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

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• 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)

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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

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• 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

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• 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