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