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Question 1Question 1
Who are these guys???
a) Two Cornell Trustees
b) Professional Engineering College Grad Students
c) The Mythbusters
d) David Skorton and Hunter Rawlings
Question 2Question 2
What does this have to do with State of the
Planet ??
Answer…..Answer…..
Today’s Lecture:
Infamous Climate Change Myths
BUSTED!Or…..
How to dazzle your climate change skeptic friends with science
Myth 1Myth 1
There’s not enough Carbon Dioxide in the atmosphere to matter.
The TruthThe Truth
But….Size doesn’t matter!
Nitrogen
Oxygen
Argon
CO2
Carbon Dioxide Carbon Dioxide
Carbon Dioxide Carbon Dioxide
4.3 µm
Carbon Dioxide Carbon Dioxide
Carbon Dioxide Carbon Dioxide
15 µm
Water Vapor Water Vapor
Water Vapor Water Vapor
Absorbed Energy is TrappedAbsorbed Energy is Trapped
Without an Atmosphere Without an Atmosphere
2.
2. Earth absorbs sunlight andRadiates it as“heat”
4. Remaining “heat” lost to space
Earth receives 240 Wm-2 from sun.
Earth must lose 240 Wm-2 to space.
E = T4
240 = 5.7x10-8 T4
T = -18ºC= 0°F
With an Atmosphere With an Atmosphere
2.
2. Earth absorbs sunlight andRadiates it as“heat”
4. Remaining “heat” lost to space
Earth receives 168 Wm-2 from sun.
Earth also receives 222 Wm-2 from the atmosphere.
E = T4
168 + 222 = 5.7x10-8 T4
T = 15ºC= 59°F
Doubling Carbon Dioxide Doubling Carbon Dioxide
2.
2. Earth absorbs sunlight andRadiates it as“heat”
Atmosphere absorbs 4 Wm-2
more radiation
Changes:1) Amount of radiation
received from atmosphere2) Temperature
Can Compute: T = 0.3F + feedbacks
1.2°C = 0.3 x 4 Wm-2
Less loss
More absorbed and
returned
Temperature increase
Little Effect
Myth 2Myth 2
Water vapor is a more important GHG than Carbon Dioxide
The Earth’s Climate SystemThe Earth’s Climate System
Components of the System Components of the System InteractInteract
CO2 increasesEarth warms
Evaporation Increases
Atmospheric Water Vapor Increases
Positive Feedback
Components of the System Components of the System InteractInteract
CO2 increasesEarth warms
Ice MeltsLess Solar Energy Reflected (more than 240 W m-2 received)
Positive Feedback
Components of the System Components of the System InteractInteract
CO2 increasesEarth warms
More EvaporationMore Clouds
Positive Feedback
Clouds Trap Terrestrial Radiation
Clouds Reflect Solar Radiation
Earth Cools Negative Feedback
Myth 3Myth 3
Carbon Dioxide will be Carbon Dioxide will be removed from the removed from the atmosphere naturallyatmosphere naturally
Carbon CycleCarbon Cycle
7 100100
90
2
0.1
Climate Carbon FeedbackClimate Carbon Feedback
Feedbacks Drive Ice Ages Feedbacks Drive Ice Ages
Slight Orbital Changes Decrease Solar Received
N.H. Cools
More Ice
N.H. Cools moreCO2 Declines
Earth Cools
Why does COWhy does CO22 decline when decline when
it’s cold?it’s cold?
Which drink is flat?
a) b)
Myth 1 RevisitedMyth 1 RevisitedIce Age Not an Ice Age
Or a Different movieOr a Different movieDinosaurs No Dinosaurs
Myth 5Myth 5
You can’t get tomorrow’s weather right, you expect me to believe your prediction for 100 years from now?
A.K.A.
Climate models are inaccurate
WEATHER
≠
CLIMATE
Typical Climate ModelTypical Climate Model
Scale MattersScale Matters
Model Validation & AttributionModel Validation & Attribution
A QuestionA Question
Choose the best day to swim in Cayuga Lake
a) Memorial Day 5/31 Air Temperature 85°
b) Labor Day 9/4 Air Temperature 85°
Features of the Climate Features of the Climate SystemSystem
Different components have different Different components have different response timesresponse times
• More on this laterMore on this later
Internal ForcingsInternal Forcings• Things like El NinoThings like El Nino
Myth 6Myth 6
There is time to avoid negative global warming
impacts
Current Impacts will persist Current Impacts will persist for centuriesfor centuries
100 years 1000 years
EmisssionsMag
nitu
de o
f R
espo
nse
Myth 7Myth 7
Ah…but what about Ah…but what about IthacaIthaca
and all those other and all those other stations Michael stations Michael
Crichton showed usCrichton showed us
Ithaca Summer TemperatureIthaca Summer Temperature
70
72
74
76
78
80
82
84
86
1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
+1.5°F-2.8°F
What are the chances?What are the chances?
124 years 0.8% chance for a record1/124
What are the chances?What are the chances?
8 years (1997-2004) 8x0.008 = 6.4% Chance of a record
What are the chances?What are the chances?
All 12 months 0.6412 = 0.00000000000047%
Myth 8Myth 8
The problem is so big, it doesn’t matter what we do
WedgesWedges
WedgesWedges
Increased efficiencyIncreased efficiency• Electric, Transportation, Heating (3 possible wedges)Electric, Transportation, Heating (3 possible wedges)• 1 wedge = 60 mpg cars1 wedge = 60 mpg cars
Switch from coal to natural gas Switch from coal to natural gas (2 possible wedges, heat (2 possible wedges, heat and electric)and electric)
• 1 wedge = 1,400 large coal plant to gas1 wedge = 1,400 large coal plant to gas
Carbon capture and storage Carbon capture and storage 2 possible wedges, electric and 2 possible wedges, electric and hydrogen)hydrogen) 1 wedge = 800 coal plants1 wedge = 800 coal plants 1 wedge = 3500 million tons/year stored1 wedge = 3500 million tons/year stored
Nuclear or hydrogenNuclear or hydrogen (2 possible wedges, electric or (2 possible wedges, electric or hydrogen)hydrogen) 1 wedge = doubling of reactors1 wedge = doubling of reactors
WedgesWedges
Wind or hydrogen Wind or hydrogen (2 wedges electric or hydrogen)(2 wedges electric or hydrogen) 1 wedge = area the size of Germany 2 million 1 wedge = area the size of Germany 2 million
windmillswindmills Solar electricity Solar electricity (1 wedge)(1 wedge)
1 wedge = NJ size area1 wedge = NJ size area Biofuels Biofuels (1 wedge)(1 wedge)
1 wedge = 1/6 of present cropland1 wedge = 1/6 of present cropland Natural sinks Natural sinks (1 wedge)(1 wedge)
Halt deforestation and double rate of forest plantingHalt deforestation and double rate of forest planting
Myth 9Myth 9
Adaptation will not be required if we choose to mitigate climate change
