atms 211 climate and climate change winter 2008
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ATMS 211 Climate and Climate Change Winter 2008 . Prof. Thornton T.A. Brian Smoliak. Times and Locations Lectures M - Th: 10:30 – 11:20 JHN 075 Disc: F 10:30 – 11:20/11:30 – 12:20 MGH 389 (AA) MGH 241 (AB). Who Am I?. Prof. in Dept. of Atmospheric Sciences - PowerPoint PPT PresentationTRANSCRIPT
ATMS 211 Climate and
Climate ChangeWinter 2008
Prof. ThorntonT.A. Brian Smoliak
Times and LocationsLectures M - Th: 10:30 – 11:20
JHN 075Disc: F 10:30 – 11:20/11:30 – 12:20
MGH 389 (AA) MGH 241 (AB)
Who Am I?Prof. in Dept. of Atmospheric
Sciences
Ph.D. in Atmospheric Chemistry
Scientific Interests:
Natural and polluted air chemistry
How pollution affects climate
How climate change affects pollution
Contact Info1. After lecture
2. Office hours (TBD) or special appointment
3. Message board (see web page)
4. Email/Phone*
Course Goals
Introduce you to climate science and the scientific process
Give you tools to understand and critically evaluate modern environmental problems
What this course is/isn’t about
YES: Current scientific theories and observations about the workings of Earth’s climate.
i.e. what, how, why?
NO: morals, philosophies, politics, etc
Course Overview
The Climate System (Present)
•Earth’s Energy Balance•Earth’s Atmosphere•Regional Climates
Climate Changes (Past-Present)
•Change and Feedbacks•The Human Influence•Natural Variations
Global Warming (Future)•Evidence•What can we expect?•Mitigation Approaches
Grading PolicyExams and Project ~ 85%•homework (15%): old exam problems•clicker questions: worth ~ 1 exam!
Plagiarism/Working Together•see UW policy on plagiarism•discussions are encouraged•on your own for exams
Grading Method•mean 2.8 – 3.2 (B- to B)
NO LATE HOMEWORKSNO MAKEUP EXAMS or QUIZZES*
Course Guidelines and Philosophy
UW Credit Hours•2hrs outside per credit hr
Lectures/Discussion
•FOR YOUR BENEFIT!•Stop me, ask questions!
•Comfortable Atmosphere•Let me know immediately
How To Do Well1. COME TO CLASS
2. TAKE GOOD NOTES
3. REVIEW YOUR NOTES
4. TEST YOURSELF
5. RELAX
GET YOUR QUESTIONS ANSWERED
MATHMath is the language of
the natural sciences
You will see and learn to use a number of equations
Think positively!
This course and your grades are based on concepts (not mathematical ability)
This Week: The climate system Read Chapter 1
Due Friday (in section): 200 word synopsis of a recent news article on climate change
200 word description of the climate of an area you’ve lived (ideally besides Seattle).
Discussion activities: math and geography surveys, what is/isn’t climate change?
Graphic Analysis Exercise
1. What are the x-y pairs in each plot (3 total)?
2. What are the units for each axis (1 x, 3 y’s)?
3. Do you see correlations, or lack thereof, where?
4. What do you find interesting/important?
5. What do you find misleading or confusing?
Summary of Graphic Analysis
Summary of Graphic Analysis
Summary of Graphic AnalysisThese measurements were
made by examining air trapped in an ice core drilled at Vostok in Antarctica.
How do you measure past Temperature in ice?
Is this just representative of Antarctica’s climate?
Announcements
• Message board
• Extra credit opportunities
• Lecture visuals
Today – Defining the problems
• Climate vs. Weather
• Climate Change (a definition)
• Global Warming
– By way of “myths and misconceptions”
Myths and Misconceptions (1)
“Its 70o today, in January? Global warming is real.”
“Hurricane Katrina was the strongest hurricane in decades. Global warming must be real.”
Weather vs. Climate
“Climate is what we expect. Weather is what we get.” – Mark Twain
What do we mean by climate change?
Long-term variation in an average property, related to weather, that is
significant compared to natural variability, or an alteration in the variability.
Recent climate change
From Intergovernmental Panel on Climate Change AR4 2007.
Figure 3.1
13.2
15
Weather Change vs. Climate Change
•A single hurricane is an example of weather.
•An increase in the number per year or average strength is a climate problem.
In the eye of Hurricane KatrinaPhoto courtesy of Prof Bob Houze’s group
Myths and Misconceptions (2)“The decrease in pirates anti-correlates with global
temperature. Thus, global warming is caused by fewer pirates (or it is causing there to be fewer pirates).”
Need to have a physical explanation for correlations to be meaningful
Myths and Misconceptions (3)
“The recent warming is just part of a natural cycle.”
Intergovernmental Panel onClimate Change
A consensus document of the scientific community
IPCC—A good course resource
“Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (sic) due to the observed increase in anthropogenic greenhouse gas concentrations” --2007
Fig 1-2 from text. Known as “Keeling Curve”.
Increasing CO2
Fig 1-3 from text. Keeling Curve and Ice Core data.
Increasing CO2
Global Warming vs. Climate Change
UN Definition of Global Warming:
“A change of climate which is attributed directly or indirectly to human activities that alter the composition of the global atmosphere... “
Myths and Misconceptions (4)
“Is global warming really such a big deal? A few degrees warmer seems harmless.”
Summary of Graphic Analysis
Seattle ice free
Seattle under mile of ice
Tice-no ice ~ -5-8o
Observed Changes in T, Sea Level, Snow/ice
Figure SPM.3
Predictions of Changes to Come
4 – 6O C increase in global average T is predicted to bring:
1. A sea level rise of 0.5 – 1.5 feet (or more) by 2100
2. Wetter wet regions and drier dry regions
3. More frequent and more intense heat waves
4. Stressed drinking and irrigation water supplies (Mtn glaciers)
5. Nearly all multi-year sea ice gone?
arctic sea ice graphic1 meter (3ft) sea level rise - world1 meter (3ft) sea level rise - SEUS
WHY?
• A goal of this course will be to understand why we should expect such changes
– What are the connections between:• Air T and precipitation patterns?• Air T and storms?• Air T and sea level/ice extent
Myths and Misconceptions (5)
“The Earth is too large/complex for humans to cause significant environmental change.”
“The hole in the ozone layer is increasing, causing global warming.”
A molecule containing three oxygen atoms found throughout the atmosphere.
Plays a role in climate, but the role is complex.
The “ozone hole” is NOT the cause of recent warming.
Ozone
Ozone “Hole”
Summary
• Climate: long-term (> 10 yrs!) average of the weather
• Climate Change: long-term variation in an average property related to weather or the natural variability of that property
• Global Warming: human-induced climate change
Today – Environmental Change Concepts
• Determining whether change is significant
• Rates of change – Mass/Energy balance
• No change
Significant?
Figure 3.1
13.2
15
From Intergovernmental Panel on Climate Change AR4 2007.
Recent Changes are Significant
Figure SPM.4
CO2 Rate of Change
1950 1960 1970 1980 1990 2000 2010
310
320
330
340
350
360
370
380
390
CO
2 Mix
ing
Rat
io (
ppm
) at
Mau
na L
oa
Year
Monthly Mean CO2 Mixing Ratio
Annual (running) Mean CO2 Mixing Ratio
Change of CO2 Rate of Change
1950 1960 1970 1980 1990 2000 2010
310
320
330
340
350
360
370
380
390
CO
2 Mix
ing
Rat
io (
ppm
) at
Mau
na L
oa
Year
Monthly Mean CO2 Mixing Ratio Annual (running) Mean CO2 Mixing Ratio
16 ppm
10 yr
Rates are often not constant in time.
1960 1970 1980 1990 2000 20100
1
2
3
R
ate
of C
hang
e of
CO
2 Mix
ing
Rat
io (
ppm
/yr)
Year
From Observations Linear Fit to Observations
Change in the CO2 Rate of ChangeCO2 is increasing faster and faster (on average!)
Has the CO2 rate of change ever been negative (<0), i.e. has CO2 decreased
at any time since 1955?
Yes No
60%
40%
1. Yes2. No
1950 1960 1970 1980 1990 2000 2010
310
320
330
340
350
360
370
380
390
CO
2 Mix
ing
Rat
io (
ppm
) at
Mau
na L
oa
Year
Monthly Mean CO2 Mixing Ratio Annual (running) Mean CO
2 Mixing Ratio
Because the CO2 rate of change is constant at 1.6 ppm/yr, it will take 175 years to
double the preindustrial amount of atmospheric CO2 (280 ppm)
Valid st
atemen
t
Inva
lid st
atemen
t
89%
11%
1. Valid statement2. Invalid statement
Summary• Rate of change of Y is the slope of a
plot of Y vs time
• Rate < 0 quantity is decreasing, Rate > 0 quantity is increasing, Rate = 0 quantity in steady state
• Rates of change are often not constant
Announcements• Two short assignments due tomorrow
(FRI) in discussion section.
• Lecture slides will appear on the course web site weekly.
• Office hours determined Monday in class by clicker vote– Tu or Th 11:30 – 12:30 or 4 – 5 pm– Brian (TA): M, Tu, W, or Th 9 – 10 AM
» And Tu or Th 5 – 6 pm
Today – Environmental Change Concepts
• Rates of Change – what they tell us
– Concepts of Mass and Energy Balance
– Residence time
• Measuring Change in the Past
1960 1970 1980 1990 2000 20100
1
2
3
R
ate
of C
hang
e of
CO
2 Mix
ing
Rat
io (
ppm
/yr)
Year
From Observations Linear Fit to Observations
Change in the CO2 Rate of ChangeCO2 is increasing faster and faster (on average!)
Summary from Yesterday• Rate of change of Y is the slope of a
plot of Y vs time
• Rate < 0 quantity is decreasing, Rate > 0 quantity is increasing, Rate = 0 quantity in steady state
• Rates of change are often not constant
Record: 1000 ~ Present day“Length” of growing seasonGood versus stressed yearsMajor fires
Unlocking “Stored” Climate Change
• Modern Instrumental Record
• Tree Rings
• Ice Cores
• Sediment cores
• Rock formations/types
Record: ~ 1Mya to ~ 20th centInert gases (CO2, CH4, N2O,…)Particulates (soot, ash, etc)Temperature??
Unlocking “Stored” Climate Change
• Modern Instrumental Record
• Tree Rings
• Ice Cores
• Sediment cores
• Rock formations/types
Record: ~ 200 MyaMicrofossils (ocean T),Volcanic glassOrganic detritusMagnetic pole location
Unlocking “Stored” Climate Change
• Modern Instrumental Record
• Tree Rings
• Ice Cores
• Sediment cores
• Rock formations/types
Detecting Change With ProxiesScientifically, the best way to detect change is to directly measure it.
Unfortunately for the timescales of interest in climate science, we weren’t always able (interested in?) to measure quantities such as temperature, precipitation, wind speed, direction, greenhouse gas levels, etc.
But, obviously we want to know what these properties were and how they changed in the past to test our understanding of how climate changes.
The study of past climate is known as paleoclimate science.
Detecting Change With Proxies
Another property/qty that is a function of property of interest.
The measured property is a PROXY for the one of interest.
Think approximate
18O/16O low
18O/16O high
18O/16O lower18O/16O evenlower
Water Cycle – Water Isotope T Proxy
Vostok Ice Core Record
T based on water isotope proxy
Stratospheric Ozone “Hole”
Course Format Course Web Site
•Consult often (weekly schedule, problem sets, lecture material)
Course Discussion Board
•Remain anonymous (or not)•Your post•TA and Prof monitor/respond
Mon-Thurs •lectures, in-class activities and quizzes (Prof)
Fridays •discussions, reviews, working examples, quizzes & exams (TA)
Global Climate Change?
Time scales
Spatial Scales