Question 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 2 What does this have to do with State of the Planet ??

Answer….. Today’s Lecture: Infamous Climate Change Myths BUSTED! Or….. How to dazzle your climate change skeptic friends with science

Myth 1 There’s not enough Carbon Dioxide in the atmosphere to matter.

The Truth But….Size doesn’t matter! Nitrogen Oxygen Argon CO 2

Carbon Dioxide

4.3 µm

Carbon Dioxide

15 µm

Water Vapor

Absorbed Energy is Trapped

Without an Atmosphere Earth absorbs sunlight and Radiates 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 =  T = 5.7x10 -8 T 4 T = -18ºC = 0°F

With an Atmosphere Earth absorbs sunlight and Radiates 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 =  T = 5.7x10 -8 T 4 T = 15ºC = 59°F

Doubling Carbon Dioxide Earth absorbs sunlight and Radiates it as “heat” Atmosphere absorbs 4 Wm -2 more radiation Changes: 1)Amount of radiation received from atmosphere 2)Temperature Can Compute:  T = 0.3  F + feedbacks 1.2°C = 0.3 x 4 Wm -2 Less loss More absorbed and returned Temperature increase Little Effect

Myth 2 Water vapor is a more important GHG than Carbon Dioxide

The Earth’s Climate System

Components of the System Interact CO 2 increases Earth warms Evaporation Increases Atmospheric Water Vapor Increases Positive Feedback

Components of the System Interact CO 2 increases Earth warms Ice Melts Less Solar Energy Reflected (more than 240 W m -2 received) Positive Feedback

Components of the System Interact CO 2 increases Earth warms More Evaporation More Clouds Positive Feedback Clouds Trap Terrestrial Radiation Clouds Reflect Solar Radiation Earth Cools Negative Feedback

Myth 3 Carbon Dioxide will be removed from the atmosphere naturally

Carbon Cycle

Climate Carbon Feedback

Feedbacks Drive Ice Ages Slight Orbital Changes Decrease Solar Received N.H. Cools More Ice N.H. Cools more CO 2 Declines Earth Cools

Why does CO 2 decline when it’s cold? Which drink is flat? a)b)

Myth 1 Revisited Ice Age Not an Ice Age

Or a Different movie Dinosaurs No Dinosaurs

Myth 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 Model

Scale Matters

Model Validation & Attribution

A 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 System  Different components have different response times More on this laterMore on this later  Internal Forcings Things like El NinoThings like El Nino

Myth 6 There is time to avoid negative global warming impacts

Current Impacts will persist for centuries Magnitude of Response

Myth 7 Ah…but what about Ithaca and all those other stations Michael Crichton showed us

Ithaca Summer Temperature +1.5°F -2.8°F

What are the chances? 124 years 0.8% chance for a record 1/124

What are the chances? 8 years ( ) 8x0.008 = 6.4% Chance of a record

What are the chances? All 12 months = %

Myth 8 The problem is so big, it doesn’t matter what we do

Wedges

Wedges  Increased 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 (2 possible wedges, heat and electric) 1 wedge = 1,400 large coal plant to gas1 wedge = 1,400 large coal plant to gas  Carbon capture and storage 2 possible wedges, electric and hydrogen) 1 wedge = 800 coal plants 1 wedge = 800 coal plants 1 wedge = 3500 million tons/year stored 1 wedge = 3500 million tons/year stored  Nuclear or hydrogen (2 possible wedges, electric or hydrogen) 1 wedge = doubling of reactors 1 wedge = doubling of reactors

Wedges  Wind or hydrogen (2 wedges electric or hydrogen) 1 wedge = area the size of Germany 2 million windmills 1 wedge = area the size of Germany 2 million windmills  Solar electricity (1 wedge) 1 wedge = NJ size area 1 wedge = NJ size area  Biofuels (1 wedge) 1 wedge = 1/6 of present cropland 1 wedge = 1/6 of present cropland  Natural sinks (1 wedge) Halt deforestation and double rate of forest planting Halt deforestation and double rate of forest planting

Myth 9 Adaptation will not be required if we choose to mitigate climate change