1. The Physics and History of Climate
Dan Britt
University of Central Florida

2. PSC 1121
This course is an introduction to the fundamental laws of physics using the history and dynamics of the Earth’s climate as our example and unifying theme
We will use physics to understand the nuts and bolts of how the climate works
How we know about past climates
How we can understand the changes
Textbook
Visualizing Weathering and Climate, by Bruce Anderson and Alan Strahler.
Extra readings in pdf

3. Class Mechanics 3 Exams: Quizzes: Make-up work
all equal weight, 80% of grade
2 in-class exams as listed in the schedule
A final which will be comprehensive
Quizzes:
I will give short in-class quizzes once or twice a week using a red half-sheet. Bring one to class!
There will be up to 20 quizzes. I will count 18, so you can miss 2 for free.
Quizzes will count 20% of the overall grade.
Make-up work
Only permitted for University-sanctioned activities and bona fide medical or family reasons.

4. Class Mechanics Extra Credit Your Professor
Write a 5-page (single spaced) research paper on a climate science topic
I will provide a list of topics
Worth up to 4% extra credit
Your Professor
Office is Physical Sciences 442
Office hours are M-W 1:30-2:30 or by appointment
Scheduling issues…..

5. Lectures I am not here to read you the book
I am what is called an “expert”
There are lots of important things that I think you NEED TO KNOW are NOT in the book….they will be in the lectures
I will post the powerpoints I use
BUT….This is NOT an on-line class
Almost every class will have a section that is NOT in the Book and will NOT be put in the on-line powerpoints….but will be on the tests.
There is no substitute for coming to class

6. How to Get an “A”
ALL of you can get A’s in this class…..I have tenure.
How to do it #1: Attend class!
People who blow off the lectures don’t do very well….figure 30% of test questions will NOT be from the book or posted slides
Sit in the front….
#2: Read the book!
Quizzes will tend to be on book material in advance of the lectures
#3: DO the extra credit!
That will usually up you a grade level

7. Dr. Britt’s quirks I ask questions….. I invite you to ask questions.
Correct answers get extra points.
I prowl around the class to ask questions.
I will always ask a couple of questions of those in the back row.
If you are shy, sit in the front row.
I invite you to ask questions.
You do get points for good questions….

8. Why am I Teaching this subject?
My “day job” is Astronomy
Background in Planetary Geology.
My work is on the geology of asteroids and comets.

9. I did climate work early in my career.
I was involved in taking some of the data that will be presented in this course
б18O from ice cores
б18O from Corals
I also worked with some of the founders paleo-climatology

10. You Hear a Lot about Climate…..
Greenhouse gasses are warming the globe
Sunspots cause warming
We are in an Ice Age
Glaciers are melting
Glaciers are advancing
Sea level is rising
CO2 is natural
CO2 is a lot higher now than in the past
CO2 is a lot lower now than in the past
The Earth was a lot warmer in the past
The Earth was a lot colder in the past

11. You Hear a Lot about Climate…..
Greenhouse gasses are warming the globe
Sunspots cause warming
We are in an Ice Age
Glaciers are melting
Glaciers are advancing
Sea level is rising
CO2 is natural
CO2 is a lot higher now than in the past
CO2 is a lot lower now than in the past
The Earth was a lot warmer in the past
The Earth was a lot colder in the past
And everything here is true…..

12. What is "Normal" for the Earth?

13. Is today's climate NORMAL for the Earth?

14. Weather and Climate
Weather is a set of all the phenomena occurring in a given atmosphere at a given time.
Weather occurs due to density (temperature and moisture) differences between one place to another.
Climate encompasses the meteorological factors in a given region over long periods of time

15. Cold snaps of times past
The first Thames frost fair was in 1607; the last in
In the 1600’s ice racing became a national sport in Holland.
The major race was thru nine cities along the canals
It was last held in the 1960’s
Winter of 1780, New York Harbor froze, allowing people to walk from Manhattan to Staten Island.

16. What is Normal?

17. What is Normal for Sea Level?

18. What is Normal?

19. What is Normal? Venus Earth Earth w/o Life Carbon Dioxide 98% 0.03%
Nitrogen
1.9%
79%
Oxygen
trace
21%
Surface Temp
477ºC
13ºC
290 ºC
Atm. Pressure (bars) 90
1.0 60

20. By 2.5 Billion years ago plankton were altering the oxygen content of the atmosphere

21. Banded-Iron Formations
Caused by the oxidization of iron
Contain about 20 times the mass of the current atmosphere in oxygen
Where did the Carbon go?
Is the current level of oxygen normal?

22. Anything Special About 21% Oxygen?

23. Lets look at conditions during the last hot period

24. Cretaceous: “abundance of chalk”

25. Climate in the Cretaceous

26. Evidence Pretty nice, but there is a down side…..
Warm-adapted vegetation and critters north of the Arctic circle
Brown-leaf evergreens
Turtles and crocodiles
No continental glaciation
Tropical conditions to 40
Coral growing at the paleolatitude of New York
NO HARD Freezes in temperate latitudes.
Pretty nice, but there is a down side…..

27. Sea Level was up to 200 meters HIGHER!

28. Why so much warmer? CO2 Geography Ocean Circulation
at ~1700 ppm… about 6 times pre-industrial levels
Geography
Continents closer to the equator
Ocean Circulation
Today the atmosphere transports about double the heat that the oceans transport
In Cretaceous that ratio was probably reversed

29. FYI: Toxicity of CO2 Current atmosphere level is ~400 ppm
OSHA says that average exposure for healthy adults during an eight-hour work day should not exceed 5,000 ppm (0.5%).
CO2 concentrations exceeding 4% are immediately dangerous to life and health.
Concentrations higher than 1,000 ppm will cause discomfort in more than 20% of occupants, and the discomfort will increase with increasing CO2 concentration.

30. Since the Cretaceous….

31. Over the past 2.7 million years the Earth’s climate has cooled and caused a series of glaciations.

32. NORMAL for the last 500,000 years is MUCH COLDER

33. 18,000 years ago the world was a much different place

35. Go to Central Park, look for yourself

36. What is the Earth’s NORMAL climate?

37. Is this NORMAL climate? There is NO “normal” climate
On average Earth’s climate has been MUCH warmer over the last 500 Myrs
Average means:
NO continental glaciation
Sea level about 350 feet higher
Temperate vegetation north of the arctic circle
Climate of the Keys as far north as Ohio