the facts and fiction of climate change kim cobb paideia school april 15, 2008
TRANSCRIPT
The Facts and Fiction of Climate Change
Kim CobbPaideia SchoolApril 15, 2008
Which of the following are scientific statements?
1) Slowing global warming costs too much money.
2) Hurricane Katrina was caused by global warming.
3) The Earth was warmer than today 60 million years ago.
Which of the following are scientific statements?
1) Slowing global warming costs too much money.
2) Hurricane Katrina was caused by global warming.
3) The Earth was warmer than today 60 million years ago.
What is CLIMATE?how the weather acts over many years
What is WEATHER?temperature, rainfall, wind changes over days
Some definitions
Why Study Climate?
CLIMATE is our best guess at what temperatureand rainfall patterns will be
- next year- next ten years- next century
CLIMATE is changing, and we need to prepare forthe future
- crops need enough water to grow- we need water to drink (but not too much) - ice is melting, sea level is rising (very slowly)
1860 1880 1900 1920 1940 1960 1980 2000
Atm
osp
her
ic C
O2 (
pp
m)
280
300
320
340
360
Tem
per
atu
re (
°C)
0.0
0.5
1.0
Average Global Temperature
Atmospheric CO2
What is CO2 (carbon dioxide)?
- represents less than 1% of the atmospheric gases- animals breathe CO2 out, plants “breathe” CO2 in- burning fossil fuels (gasoline, oil) dumps CO2 into the atmosphere- more atmospheric CO2 warms the atmosphere
greenhouse gases in the atmosphere trap heat at the Earth’s surface and prevent it from escaping.
1
2
3
4
without greenhouse gases average temp of Earth would be -18ºC instead of 15ºC
So the greenhouse effect is a good thing!
we are increasing the greenhouse effect by adding CO2 to the atmosphere
The consequences of climate change
in 100 years….
average global temperatures will rise by 2-14F
sea level will rise by 7-22 inches
rainfall patterns will change
Why is there so much uncertainty in future climate?
One uncertainty comes from unknown future CO2
Will we join international plans to reduce CO2?Will we ignore the problem?What will other countries like China and India do?
Decisions made NOW will effect your grandchildren!
Another uncertainty comes from imperfect climate models
Over 20 models are used, because we don’t know whichone is right.
Tools to study Paleoclimates -- “ancient” climates“the past is the key to understanding the present”
Corals
- oceanic, tropical- 100’s yrs long
Sediments
- along coastlines- 10,000’s yrs long- Ice Ages
Tree Rings
- continents-1000’s yrs long
Ice Cores
- North, South poles- 10,000’s yrs long- Ice Ages
Studying Climate with Corals
What is a CORAL?a tiny animal in the shallow tropical ocean that lives colonially and grows a hard rock skeleton
corals can live for hundreds of years
My Research: Studying Climate with Corals
Goal: to compare past tropical Pacific climate with present-day climate
Palmyra Island
Palmyra IslandHow it works:1) coral skeletons record
temperature changes2) we can count back 1000
years to read temperature
Corals provide long records of past climate that can be compared to present climate (is it different? how?)
Science can be fun!
Global warming is very real, but the exact consequences are uncertain.
Example:Driving in a car is dangerous, but you don’t know when youmight have an accident.
Do you wear a seatbelt? YES!
We must begin to act to reduce global warming BEFOREwe know the exact consequences.
The good news: humans are VERY smart!
Three strategies to reduce CO2:1)use less energy
- drive less, drive smaller cars- conserve electricity
2) make “clean” energy- solar power, wind power, nuclear energy
3) take CO2 out of the sky (more difficult)
- 50%
- 50%
CO2
+ $$
cost
- $$
What can YOU do?
Bug your parents to buy flourescent light bulbs!
When you starting driving, don’t drive an SUV.
Save electricity wherever you can.
Think about a job in science and engineeringor politics, or education.
Can you think of three things you can do to start saving the planet?
A climate scientist’s plea to the next generation:
seek out information, ask questions, get the facts, and then VOTE
distinguish the science of global warming from the politics/economics of global warming
recognize uncertainties, but don’t be paralyzed by them
[buy flourescent light bulbs, don’t drive SUV’s, eat your broccoli]
THANK YOU
[email protected] ‘Kim Cobb’ for web-site
Studying Climate with Corals
What is a CORAL?a tiny animal in the shallow tropical ocean that lives colonially and grows a hard rock skeleton
corals can live for hundreds of years
My Research: Studying Climate with Corals
Goal: to compare past tropical Pacific climate with present-day climate
Palmyra Island
Palmyra IslandHow it works:1) coral skeletons record
temperature changes2) we can count back 1000
years to read temperature
Summary
We need to understand more about how climate is changing.
Corals provide long records of past climate that can be compared to present climate (is it different? how?)
Science can be fun!