Physics 140 Greenhouse Effect

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Physics 140Greenhouse Effect

• Professor Amitabh Lath

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What is the global warming controversy?
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The Global Warming Controversy

• Is the earth warming? (Detection)
• Are human activities responsible for this
  warming? (Attribution)
• What should we do about it? (Policy)

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Global Temperature is Rising
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Global Temperature is Rising
But what is Temperature?
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Global Temperature is Rising
But what is Temperature?
Related to HEAT?
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Definition of Temperature
A measure of Energy of motion (kinetic energy)
Calm ? lower temperature
Fidgety ? higher temperature
So what is Energy?
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What is Energy?

• Hard to define (that which does work?)
• Conserved
• Can change from one type to another
• Our focus reversible vs irreversible change
• Irreversible loss or inefficiency etc.
• Physics Definition Force x distance
• How much energy imparted to the eraser
• by lifting it from the floor to the table?

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What is Energy?

• Hard to define (that which does work?)
• Conserved
• Can change from one type to another
• Our focus reversible vs irreversible change
• Irreversible loss or inefficiency etc.
• Physics Definition Force x distance
• How much energy imparted to the eraser
• by lifting it from the floor to the table?

Dont worry, this isnt going to turn into an
intro physics course.
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Turning Energy into Temperature
COLD
Energy
HOT
Putting Energy into cold object makes it hot.
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Turning Energy into Temperature
COLD
Hot object RADIATES Energy and becomes cold.
Not the same sort of energy that you fed into it
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Heat Radiation

• All objects radiate Energy
• Unless you are at absolute zero Kelvin.
• Nothing can be at absolute zero Kelvin.
• If you prevent (some) radiation, object will cool
  down less (example, throw a blanket around it).

WARM
HOT
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Basic Concepts
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Multipliers

• Kilo (k) 1000x (a thousand
  things)
• Mega (M) 1,000,000x (a million, 6
  zeros)
• Giga (G) 1,000,000,000x (a billion, 9
  zeros)
• Tera (T)1,000,000,000,000x (a trillion, 12
  zeroes)
• Example
• Average yearly income in the US is about
  50,000 per household
• 50 kilodollars (k)
• The average yearly salary in major league
  baseball (2008) was
• 3,154,845 3.2 megadollars (M)

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Energy

• Basic SI unit of energy Joules
• 1 Newton of force, used for 1 meter
• A 2 kg mass moving at 1 m/s has 1 Joule of
  Kinetic Energy
• Typical human sheds 100 Joules of heat energy
  per second
• Conversions
• 1 Joule 0.239 calories ?? 1 calorie 4.2
  Joules
• Note food calories are 1000 calories (1 food
  calorie 1 kilocalorie)
• 1 Joule 9.5 x 10-4 BTU ?? 1 BTU 1060 Joules
• 1 Joule 2.8 x 10-7 kilowatt-hours (kWh) ??
• 1 kWh 3,600,000 Joules or 3.6
  MegaJoules (MJ)

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Power

• Energy per unit time
• Joules per second WATTS
• BTU per hour, kilocalories per lunch period
• Measures RATE at which ENERGY flows
• I climb a flight of stairs (70kg, up 3 meters)
• I expended 2060 Joules.
• If I climbed in 1 min ? rate was
• 2060 J/ 60s 34.3 Watts (34.3 W)
• If I climbed in 15 mins ? rate was 2.3 W
• If I climbed in 1 hour ? rate was 0.6 W

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Various Power Sources/Sinks

• Tenth of a Watt (0.1 Watt) 5 solar cell from
  Radio Shack.
• 1 Watt radio speaker (1W), bicycle dynamo (3
  W)
• 10 Watts night light
• 100 Watts Regular (incandescent) light bulb
• 1000 Watts (1kW) 1.34 horsepower
• hair dryer, college FM radio
  transmitter,
• avg solar energy falling on 1 square
  meter at earth

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Various Power Sources/Sinks

• 100 kW (134 hspwr)
• mechanical energy
  output of typical car.
• 1 MW AM radio transmitter, Solar Power array
• 10 MW Rutgers Co-Generation power plant (Busch
  Campus)
• 100 MW Refinery on NJ Tpke, Big wind farms,
  small nuclear reactor
• 1 GW Coal Power plant (0.5 GW), small US city.
• 1 TW US power consumption (1.4 TW Electrical,
  3TW all)

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Power x Time Energy

• My refrigerator uses 500 W (Power).
• How much Energy do I use in 1 month?
• Answer 1 month 30 days 259,200 seconds
• so, Energy 500 J/sec x 259200 sec
• 1,296,000,000 Joules
• ? 1.3 x 109 J (1.3 GJ or
  1300 MJ)
• But my utility bill will say
• 360 kilowatt-hour (kW-hr) (if I only ran the
  fridge).
• 1 kW-hr 3.6 MJ

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SYLLABUS
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Physics 140 Plan

• Lectures 1 and 2
• Define Energy and Temperature
• Do some units
• Whats the difference between
• Joules and BTU?
• Kilowatts and Kilowatt-hours?
• Watts and horsepower?
• Sun as a source of Energy
• It all starts here.

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Physics 140 Plan

• Lecture 3
• Radiation Law
• Basic Mechanism behind Greenhouse Effect
• Compare Earth/Mars/Venus
• Mid/low/hi greenhouse effect planets
• Lecture 4
• Earths atmosphere (including history)
• Greenhouse gases in the atmosphere

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Physics 140 Plan

• Lecture 5
• How do Greenhouse Gases get into atmosphere?
• Historical data
• Keeling Plot
• How much is too much?
• Correlate with global temperature

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Basic PlotsTemperature and CO2 vs time
NASA Goddard Institute for Space Studies
Keeling Plot
Are these correlated? Is the right one causing
the left one?
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Physics 140 Plan

• Lecture 6
• Human Energy consumption and Greenhouse gases.
• How much are we putting into the atmosphere?
• Given the mechanism (Lecture 3) could we be
  causing Global Warming?
• Which gases contribute most
• (concept of CO2 equivalents)

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Physics 140 Plan

• Lecture 7
• Human energy budget
• How much energy does world population need to
• Various scenarios (America vs. Europe vs. others)
• Needs housing, transport, etc
• Lecture 8
• Filling our need for energy
• Sources Fossil fules (coal/oil gas)
• Renewables (solar PV, solar
  thermal, wind, etc)

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Physics 140 Plan

• Lecture 9
• World energy consumption future
• What is going on now
• By Country/region
• By source
• What is the future?
• Various scenarios
• EXAM 1

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Physics 140 Plan

• Lecture 10
• Climate modeling
• Basic methods and their drawbacks
• Successes and limitations of various models
• Projections (based on different CO2 scenarios)
• Lecture 11
• Impacts of Global Warming (Overview)
• Lecture 12
• Impacts of Global Warming (heat/ sea level rise

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Physics 140 Plan

• Lecture 13
• Impacts of Global Warming (cont.)
• Droughts and floods
• Ecosystems and agriculture
• Frequency of severe weather events
• Lecture 14
• Impacts of Global Warming
• The Arctic
• Lecture 15
• Impacts of Global Warming
• Assesing impacts and assigning costs/probabilities
  

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Physics 140 Plan

• Lecture 16
• Addressing Global Warming
• What works
• Mass Media and GW
• Lecture 17
• Conservation
• New Technologies
• EXAM 2

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Physics 140 Plan

• Lecture 18
• Technological Solutions (continued)
• sequestration
• Ocean seeding
• Troposphere seeding
• Lecture 19
• Putting it all together
• Socolows Wedges
• International efforts (Kyoto, etc)

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Physics 140 Plan

• Lecture 20
• Economics of Global Warming
• Cap and Trade
• Carbon Tax
• Lecture 21
• Guest lecture on Energy Trading
• Lecture 22
• Open discussion What can we do today?
• FINAL EXAM