D E N N I S L . H A R T M A N N D E P A R T M E N T O F A T M O S P H E R I C S C I E N C E S

D A Y 1 : S e p t e m b e r 2 9 , 2 0 1 1

ATM S 111, Global Warming: Understanding the Forecast

About Me

  Professor: Dennis Hartmann   Home town: Sublimity, Oregon

  14 Miles east of Salem, Oregon, in the foothills of the Cascades   Dad was a lumberjack/laborer   Mom was a homemaker/cannery worker

About Me

  <1840 Vast forest opened near Sublimity by large Native American burn (Calapooia, Santiams, Mollalla).

  1850 James M. Denny gets a quarter section lays a plat for the town.

  1857 Sublimity College: Milton Wright, first President (Wright Brothers father)

  1859 Oregon became a State   1860 Three largest cites: Portland (2874), Sublimity (1,221)

and Eugene (1183)   1860 Civil War broke out. Settlers returned to their native

states. Sublimity nearly deserted.

About Me

From Unwanted Tower to a New Hit on eBay By SARAH KERSHAW Published: May 20, 2003

SUBLIMITY, Ore., May 17 — Some things are just a little too expensive these days. For Sublimity, a rural town of 2,580 people in northern Oregon, dismantling the old water tower on Church Street is one of them.

It would cost Sublimity roughly $20,000 to take down the tower, a 50,000-gallon tank built in 1948 and idle for the last four years after a new one was installed. With Oregon and the rest of the region as cash-poor as they are, that's a pretty penny for place like Sublimity.

So would anybody out there like to buy this gorgeous water tower?

Sublimity put the tank up for auction on eBay for $1, after its four city council members voted to list "One (1) 50,000 gallon elevated steel tank" on the auction site.

"We would hope they are aware of what they are getting into," said Josh Williams, a city council member and a captain for the Sublimity Fire District. "But I think one of them will take it away."

The Columbus Day Storm 1962

Education

  BS, University of Portland (Oregon) Mechanical Engr.   PhD, Princeton University (NJ) Geophysical Fluid Dynamics   Postdoc, McGill University (Montreal, Quebec) (1 yr)   Visiting Scientist, National Center for Atmospheric Research

Boulder, CO (1 yr)   Assistant Professor, UW Atmospheric Sciences (1977)

  Expertise is in Climate Science, First time teaching ATM S 111   Very excited about conveying science, but also technology,

economics, politics – from perspective of scientist.

Teaching Assistants

  Two TAs in this class   Chen Zhang

 Studies climate dynamics

  Felipe Lopez-Hilfiker  Studies atmospheric chemistry

Goals of the Class

 We’re going to learn about:   The science behind global warming   How to critically evaluate what you hear about climate and global

warming   Related issues such as energy alternatives   The role of science in formulating effective societal responses

Class Outline

  Weeks 1-2: Overview and global warming science   Weeks 3-5: Impacts of climate change   Week 6: Climate records, long ago and recent past   Week 7: Climate modeling and future projections   Week 8: The debate   Week 9: Solutions   Week 10: Economics and politics

Required Course Materials

  The Rough Guide to Climate Change, 3rd edition by Robert Henson

  Additional articles on class website   “Clickers” for in-class questions and activities

  Turning Technologies ResponseCard RF   Check UW Classifieds (link from course

homepage) for used clickers

Grading

  Comprehensive final: 25%   Quizzes (3): 40%   Homework: 20%   In-class activities: 15%   Extra credit: up to 5%

“Quiz” Sections

  Actually for discussion, review, and problem solving   In class activities for points (no clickers needed)   Go to your registered section only (there’s only room

for 30 students in some classrooms)

Course Webpage

http://www.atmos.washington.edu/~dennis/111/

Check it often! It’ll have all reading assignments, links to the HW, slides from lectures, etc

Homework

  Online using Catalyst (link will be posted on the class website once the first assignment is ready)

  Use Firefox browser and UWIN ID

  Enrollment key: longwave (needed first time only)

  OK to discuss problems with classmates, but turn in your own answers

Clicker Questions

  Half credit for wrong answers   Full credit for right answers or survey questions   Use only your own clicker

Other Ground Rules

  Respect!   This can be a politically charged topic: respect your neighbor’s

views

  No talking, texting, e-mails, etc   We’ll take a 10 minute break each class period

First…

  A basic summary of the science of global warming   Reading assignment for the summary:

 Rough Guide p. 3-22, “Climate Change: A Primer”

  Also for next class:  Rough Guide p. 23-35, “The Greenhouse Effect”

  If it’s about restaurants in Prague, you’ve probably got the wrong Rough Guide

This one!

The Atmosphere From Space

Weather versus Climate

  Weather varies from one day to the next   Climate: averages of the weather over a longer period of time

  Example:   You put on clothes for the weather…

  Should I pack an umbrella?   You buy clothes for the climate…

 Going where the climate suits my clothes – lyrics from Lonesome Road Blues (traditional, e.g., Henry Whitter, 1924)

 Going where the weather suits my clothes - more recently Harry Nillson, Everybody's Talkin' at Me – 1969 Misuse of weather/climate dichotomy unless he is moving very frequently.

  Both weather and climate can be predicted with some fidelity

What Factors Influence Climate?

  Sunshine   And relatedly, latitude

  Topography/mountains   Proximity to oceans and large lakes   Ocean currents   Presence of trees/vegetation   Etc.

The atmosphere from space…

90% of the mass of the atmosphere is within 16 km (10 miles) Distance from equator to pole = 10,000 km

Relatively speaking, the atmosphere is about half as thin as typical seams on a basketball

It’s remarkably thin…

A thin atmosphere means we can change atmospheric composition

We Modify the Composition of the Atmosphere

  Carbon dioxide (CO2) has been measured at Mauna Loa, Hawaii since 1958

“Keeling curve”: first measured by David Keeling in March ’58

~ 25% increase since the first measurement ~ 30% increase since pre-industrial times

Human induced: Due to fossil fuel burning (80%) and deforestation (20%)

Let’s Look Way Back to 450,000 Years

  We’re at 390 ppm now

Natural variation over Ice Age Cycles: 180-280 ppm

Current rate of increase is 100-1000 times faster than nature can change CO2

Present Past

280

180 Img src: Global Warming Art

CO2 is a Greenhouse Gas

  Greenhouse gases slow heat loss to space   Has been known for a long time (J. Fourier in 1824)

This is why it’s hot

The Sun heats the Earth.

Greenhouse gases cause the Earth to be a lot warmer than if there was no atmosphere:

58o F or 32o C warmer

Joseph Fourier

The natural greenhouse effect

The Earth is Warming

  More CO2 -> warmer atmosphere (eventually)   Has it been getting warmer?

It’s warmed about 0.8o C (1.5o F) in the last 130 years

Especially rapid warming since the mid-’70s

9 out of the top 10 hottest years on record were the last 9 years

0o F

1o F

0.5o F

-0.5o F

Src: NASA GISS

Warming has happened almost everywhere. Northern high latitudes have warmed the most. Land has warmed more than ocean.

Src: IPCC AR3

Hasn’t This Data Been Faked?

  No, we’re confident about the thermometer data   Recent controversy has been about tree ring

reconstructions (known as the “hockey stick”):

This is much less certain, and only represents the Northern Hemisphere anyway (gray area indicates uncertainty).

We’ll discuss this and other controversies more later…

0o F

1o F

-1o F

-2o F

Src: IPCC AR3

What Else is Happening?

  As temperatures rise

  Sea level is rising 20 cm = 8 inches

  Snow cover is decreasing

Src: IPCC AR4

Also glaciers are melting, Arctic sea ice is melting, species are shifting, etc

Could the Sun be the Cause?

  No, the Sun is nearly the weakest it’s been in 30 years

Deepest solar minimum in terms of sunspots in 100 years (more sunspots slightly hotter Sun)

Sola

r ou

tput

1975 Year 2010

In general, strength of solar variability is very weak (0.1% from max to min)

Suns

pot n

umbe

r

Sun is weak now, just coming out of a long minimum

What’s Predicted for the Future?

  A fundamental uncertainty is future human behavior   Will we reduce emissions, or will we burn fossil fuels more and

more rapidly?   How quickly will developing countries get rich?

  Emissions scenarios provided by economists, policy makers, etc:

Src: IPCC AR3

Business as usual

Utopia

Intermediate

Future CO2 levels

  The scenarios produce the following CO2 values:   Really high CO2 levels are possible if we don’t cut emissions

 But even in “utopia” scenario, CO2 will likely increase much more than it has already

Same plot from before of CO2 over last 400,000 years

Business as usual

Intermed.

Utopia

Future Temperature Rise Predictions

  Uncertainty both in human behavior (colors) and climate feedbacks (shaded area around)

Climate models are saying “you ain’t seen nothin yet”

  Business as usual would mean 3-4o C (5.5-7o F) more warming

 “Utopia”: 1.5-2o C (3-4o F) warming

  Even if we kept present CO2 levels, there would still be a bit more warming

0o F

2o F

4o F

6o F

8o F

10o F

Src: IPCC AR4

Controversy About All This?

  No doubt about these things:   The greenhouse effect   That CO2 and other greenhouse gases are increasing due to man   That temperatures are rising

  Skeptics tend to argue for:   “Negative feedbacks” that keep the temperature changes small   Or that warming wouldn’t be such a bad thing   Or about flaws in a particular study

  Be wary:   Much of “the debate” (on both sides) is not very scientific   Let’s sort out fact from fiction!

A Sampling of Future Topics

  “Paleoclimate”:   Ice Ages and hot climates of the past like the Cretaceous

Last Glacial Maximum Present

Ice sheet extent

The Cretaceous Seaway

Volcanoes and Climate

  How the Earth cools after certain types of volcanoes…

Eruption of Mount Pinatubo in June 1991 and its effect on global temperatures

And Man-Made Volcanoes!

  “Geoengineering”: using technology to cool the Earth   People are considering things like

  Putting volcanic-type particles into the stratosphere   Space mirrors   Cloud machines   Fake trees

Right picture from Rolling Stone article “Can Dr. Evil Save the World?”

The Effect of Climate on Nature

  Cute animal pictures!!

Climate and the Rainforests

  The effect of burning tropical rainforests on climate   And the effect of climate change on rainforests

Rainforests burning over the Brazil-Bolivia border

Satellite photo from NASA (MODIS): Locations of fires marked by (enhanced) red dots

Winners and Losers

  Who will benefit… •  And who will it hurt the most?

New shipping lanes

Floods

  Floods in Mississippi Basin 2011

Red River Fargo, ND

Floods

  Floods in Australia 2010

And Droughts…

  Lake Chad

UNEP

Alternative Energies & Fuels

  Pros and cons of wind, solar, nuclear, ethanol, etc

Science and Policy

  The ozone problem   This was solved by the most efficient interaction between

science and policy to date

✕ Discovery of the ozone hole led to a ban on all CFCs

Why is global warming so much more difficult from a policy perspective?

Let’s Get Started!

  First topic: the science of climate   What are the key factors that determine the

temperature of Earth?