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Climate Change: The Move to Action
(AOSS 480 // NRE 480)
Richard B. Rood
Cell: 301-526-8572
2525 Space Research Building (North Campus)
[email protected]
http://aoss.engin.umich.edu/people/rbrood
Winter 2010
February 2, 2010
Class News
• Ctools site: AOSS 480 001 W10
• On Line: 2008 Class
• Reading
– IPCC Working Group I: Summary for Policy
Makers
Make Up Class / Opportunity
• Make up Class on March 8, Dana 1040,
5:00 – 7:30 PM, Joint with SNRE 580
– V. Ramanathan, Scripps, UC San Diego
– Please consider this a regular class and make
it a priority to attend.
Think about Projects
• Today we will discuss project topics and think
about teams ….
– Are there groups that have self organized?
• What seems especially interesting and relevant
(to me)?
– The near-term solution space.
• What seems especially difficult to me
– Carbon market versus carbon tax
– Social justice as a driver of the problem versus a part
of the problem
What can we do now?
• Some ideas
– Pacala and Socolow, Science, 2004
– Socolow and Pacala, Scientific American,
2006
– Carbon Mitigation Initiative
Class Projects
• Think about Projects for a while
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The role of the consumer
Energy efficiency / Financing Policy
Science influence on policy, Measurements of carbon, influence
Role of automobile, transportation, life style
Water, fresh water, impact on carbon,
Geo-engineering, public education, emergency management,
warning,
Water, insurance, Midwest development, Michigan, regional
Dawkins, socio-biology
What leads to a decision
What does it really mean in the village
Geo-engineering, urban sustainability
US Policy, society interest, K-12, education
Class Projects
• Think about Projects for a while some previous
ideas
– Impact of local climate change efforts
– Important sources of scientific uncertainty and how
they impact policy
– Urban planning
– Geo-engineering
– Natural sinks in carbon market
– Ecotourism
– Ecosystem services and valuation
– Evaluation of Kyoto Impact
– Public opinion, comparative study, impact on what we
do
Today
• Foundation of science of climate change
(continued)
Some Basic References
• Rood Climate Change Class
– Reference list from course
• Rood Blog Data Base
• Koshland Science Museum: Global Warming
• IPCC (2007) Working Group 1: Summary for
Policy Makers
• IPCC (2007) Synthesis Report, Summary for
Policy Makers
• Osborn et al., The Spatial Extent of 20th-Century
Warmth in the Context of the Past 1200 Years,
Science, 311, 841-844, 2006
Let’s Build up the Scientific Foundation
• Which means lets build up
– The observational foundation
– The theory foundation
– The validation foundation
Let’s look at just the last 1000 years
Surface temperature and CO2 data from the
past 1000 years. Temperature is a northern
hemisphere average. Temperature from
several types of measurements are consistent
in temporal behavior.
{
Note that on this scale, with more time
resolution, that the fluctuations in
temperature and the fluctuations in CO2
do not match as obviously as in the
long, 350,000 year, record.
What is the cause of the temperature
variability? Can we identify
mechanisms, cause and effect? How?
What do we see from the past 1000 years
• On time scales of, say, decades the CO2 and T are not
highly correlated.
• Periods on noted warmth and coolness are separated by
changes in average temperature of only 0.5 F.
• Changes of average temperature on this scale seem to
matter to people.
– Regional changes, extremes?
• Recent changes in both T and CO2 are unprecedented in
the past several hundred thousands of years.
– And the last 10,000 years, which is when humans have thrived in
the way that we have thrived.
Let’s Build up the Scientific Foundation
• Which means lets build up
– The observational foundation
– The theory foundation
– The validation foundation
Conservation Principle
Conservation (continuity) principle
• There are certain parameters, for example, energy,
momentum, mass (air, water, ozone, number of atoms,
… ) that are conserved.
– “classical” physics, we’re not talking about general or special
relativity!
– Simple stuff, like billiard balls hitting each other, ice melting
• Conserved? That means that in an isolated system that
the parameter remains constant; it’s not created; it’s not
destroyed.
• Isolated system? A collection of things, described by the
parameter, that might interact with each other, but does
not interact with other things. Nothing comes into or
goes out of the system … or, perhaps, nothing crosses
the boundary that surrounds the system.
Conservation (continuity) principle
• There are many other things in the world
that we can think of as conserved. For
example, money.
– We have the money that we have.
• If we don’t spend money or make money
then the money we have today is the
same as the money we had yesterday.
Mtoday = Myesterday
That’s not very interesting.
Conservation (continuity) principle
Mtoday = Myesterday
Living in splendid isolation
Conservation (continuity) principle
Income
Mtoday = Myesterday + I - E
Let’s get some money and buy stuff.
Expense
Conservation (continuity) principle
Income
Mtoday = Myesterday + N(I – E)
And let’s get a car
Expense per month = E
Get a job
Income per month = I
N = number of months
I = NxI and E= NxE
Expense
Some algebra and some thinking
Mtoday = Myesterday + N(I – E)
Rewrite the equation to represent the difference in money
(Mtoday - Myesterday ) = N(I – E)
This difference will get more positive or more negative as time goes on.
Saving money or going into debt.
Divide both sides by N, to get some notion of how difference changes with time.
(Mtoday - Myesterday )/N = I – E
Some algebra and some thinking
(Mtoday - Myesterday )/N = I – E
If difference does NOT change with time, then
I=E
Income equals Expense
With a balanced budget, how much we spend, E, is related to how much we have:
E = eM
(Mtoday - Myesterday )/N = I – eM
Some algebra and some thinking
(Mtoday - Myesterday )/N = I – eM
If difference does NOT change with time, then
M = I/e
Amount of money stabilizes
Can change what you have by either changing
income or spending rate
All of these ideas lead to the concept of a budget:
What you have = what you had plus what you earned minus what you spent
Conservation Principle seems intuitive for money
• The conservation principle is posited to apply to
energy, mass (air, water, ozone, ... ),
momentum.
• Much of Earth science, science in general, is
calculating budgets based on the conservation
principle
– What is the balance or imbalance
• If balanced, then we conclude we have factual information on
a quantity.
• If unbalanced, then there are deficiencies in our knowledge.
Tangible uncertainties.
Conservation (continuity) principle
EnergyIncome
from the Sun
Mtoday = Myesterday + I - E
Earth at a certain
temperature, T
Let’s get some money and buy stuff.
Energy emitted
Expenseby Earth
(proportional to T)
Some jargon, language
• Income is “production” is “source”
• Expense is “loss” is “sink”
• Exchange, transfer, transport all suggest
that our “stuff” is moving around.
The first place that we apply the conservation
principle is energy
• Assume that Energy is proportional to
temperature, T, if the average temperature of
the Earth is stable, it does not vary with time.
Tnext year - Tlast year
 0  Production - Loss
change in time
Production  Loss
And the conservation of CO2
• Assume that total CO2 is balanced. It sloshes
between reservoirs and gets transported
around.
CO2 next year - CO2 last year
change in time
Production  Loss
 0  Production - Loss
Let’s think of this as a cycle
SOURCES
CHANGE
[CO2 ]
 PCO2  LCO2
t
SINKS
EXCHANGE
Equilibrium and balance
• We often say that a system is in equilibrium if
when we look at everything production = loss.
There might be “exchanges” or “transfers” or
“transport,” but that is like changing money
between a savings and a checking account.
– We are used to the climate, the economy, our cash
flow being in some sort of “balance.” As such, when
we look for how things might change, we look at what
might change the balance.
Need to think about our “system”
• What about carbon dioxide?
What are the
mechanisms
for production
and loss of
CO2?
Important
things in this
figure.
System?
• When we look at the Earth and talk about
climate change what is our system?
System?
• When we look
at the Earth
and talk about
climate change
what is our
system?
Energy from the Sun
Energy emitted by Earth
(proportional to T)
System?
• But our focus is at the
surface of the Earth.
We change “stuff” in
the system as a
whole, and then we
want to know how the
balance of energy at
the Earth’s surface will
change.
In both of these cases our
definition of system implicitly
looks at the intersection of
climate and people.
Energy from the Sun
Energy emitted by Earth
(proportional to T)
One of my rules
• In the good practice of science, of problem
solving, to first draw a picture.
Conservation (continuity) principle
Energy from the Sun
Stable Temperature of
Earth could change
from how much
energy (production)
comes from the sun,
or by changing how
we emit energy.
Earth at a certain
temperature, T
Energy emitted by Earth
(proportional to T)
The Greenhouse Effect
(Is this controversial?)
SUN
Based on conservation of energy: If the
Earth did NOT have an atmosphere,
then, the temperature at the surface of
the Earth would be about -18 C ( ~ 0 F).
Earth
But the Earth’s surface temperature is
observed to be, on average, about 15 C
(~59 F).
This greenhouse effect in not controversial.
This surface temperature,
which is higher than
expected from simple
conservation of energy, is
due to the atmosphere. The
atmosphere distributes the
energy vertically; making the
surface warmer, and the
upper atmosphere cooler,
which maintains energy
conservation.
The Greenhouse Effect
(Is this controversial?)
SUN
Based on conservation of energy: If the
Earth did NOT have an atmosphere,
then, the temperature at the surface of
the Earth would be about -18 C ( ~ 0 F).
Earth
But the Earth’s surface temperature is
observed to be, on average, about 15 C
(~59 F).
This greenhouse effect in not controversial.
This surface temperature,
which is higher than
expected from simple
conservation of energy, is
due to the atmosphere. The
atmosphere distributes the
energy vertically; making the
surface warmer, and the
upper atmosphere cooler,
which maintains energy
conservation. We are making
the atmosphere “thicker.”
Some aspects of the greenhouse effect
• Greenhouse warming is part of the Earth’s natural
climate system.
– It’s like a blanket – it holds heat near the surface for a while
before it returns to space.
• Water is the dominant greenhouse gas.
• Carbon dioxide is a natural greenhouse gas.
– We are adding at the margin – adding some blankets
• Or perhaps closing the window that is cracked open.
• N20, CH4, CFCs, ... also important. But in much smaller
quantities.
– Molecule per molecule stronger than CO2
• We have been calculating greenhouse warming for a
couple of centuries now.
The first place that we apply the conservation
principle is energy
• If we change a greenhouse gas e.g. CO2, we change
the loss rate. For some amount of time we see that
the Earth is NOT in balance, that is ΔT/Δt is not zero,
temperature changes.
temperatur e difference T

 H - T
time difference
t
H  Heating  Production
T  Cooling  Loss
Conservation (continuity) principle
Energy from the Sun
Stable Temperature of
Earth could change
from how much
energy (production)
comes from the sun,
or by changing how
we emit energy.
Earth at a certain
temperature, T
Energy emitted by Earth
(proportional to T)
The first place that we apply the conservation
principle is energy
• We reach a new equilibrium
T
 0  H - T
t
Production  Loss
H
Changing a greenhouse gas
T
changes this

The sun-earth system
(What is the balance at the surface of Earth?)
SUN
Based on conservation of energy: If the
Earth did NOT have an atmosphere,
then, the temperature at the surface of
the Earth would be about -18 C ( ~ 0 F).
What else could be
happening in this system?
Earth
But the Earth’s surface temperature is
observed to be, on average, about 15 C
(~59 F).
This greenhouse effect in not controversial.
Conservation of Energy
• The heating could change. That is the sun, the
distance from the sun, ... .
T
 H - T
t
H  Heating  Production  Loss
T  Cooling  Loss
The first place that we apply the conservation
principle is energy
• We reach a new equilibrium
T
 0  H - T
t
Production  Loss
H
T

Can we measure the
imbalance when the Earth is
not in equilibrium?
Changes in orbit or solar
energy changes this
Still there are many unanswered questions
•
We know that CO2 in the atmosphere holds thermal energy close to the
surface. Hence, more CO2 will increase surface temperature.
– Upper atmosphere will cool.
– How will the Earth respond?
• Is there any reason for Earth to respond to maintain the same average surface
temperature?
•
Why those big oscillations in the past?
– They are linked to solar variability.
– Release and capture of CO2 by ocean plausibly amplifies the solar oscillation.
• Solubility pump
• Biological pump
•
What about the relation between CO2 and T in the last 1000 years?
– Look to T (temperature) variability forced by factors other than CO2
•
• Volcanic Activity
• Solar variability
• CO2 increase
Radiative forcing other than CO2?
– Other greenhouse gases
– Aerosols (particulates in the atmosphere)