AAUW St. George UT Branch Member Candice Hansen-Koharcheck, PhD, gave a presentation on "Climate Change: Scientific Fact vs. Political Fiction" at the March 2015 luncheon. Candice is a senior research scientist at the Planetary Science Institute who works on NASA un-manned (robotic) spacecraft missions. She has a Ph.D. in Planetary Science. Currently she is a member of the flight teams for the Cassini spacecraft, in orbit around Saturn, the Mars Reconnaissance Orbiter, at Mars, and the Juno mission, headed to Jupiter, from her office in St. George.

1. Climate Change: Scientific Fact
vs. Political Fiction
C. J. Hansen-
Koharcheck

2. The Difference between
Climate and Weather
• Weather is what happens on any given day
– Sunshine
– Hurricanes
– Snow
– Wind
– …
• Climate is the long-term average of atmospheric
conditions, usually averaged over 30 years
– A consistent increase in the average winter (or summer or
yearly) temperature over a number of years is considered
climate change
– The average global temperature has increased 0.5 deg over
the last 30 years

3. Just the Facts…
1. CO2 is a greenhouse gas
2. The amount of CO2 in our atmosphere is
increasing
3. We are responsible for the rising levels of CO2
in our atmosphere
Not so clear
• What are the consequences?

4. 1. CO2 is a greenhouse gas
• What is a greenhouse gas?
– A gas which absorbs thermal radiation (heat)

5. 1. CO2 is a greenhouse gas
• How does a greenhouse gas warm the
atmosphere?

6. Other greenhouse gases
• Other molecules:

7. Our Goldilocks Planet
Venus:
Too much
Average surface
temperature =
864 F
Mars:
Too little
-80 F
Earth:
Just right
57 F
Currently the earth has just the right amount of
greenhouse gases …

8. The Earth has experienced
Climate Change in the Past
• Much warmer climate millions of years ago
0

9. 2. The amount of CO2 in our atmosphere
is increasing
• These are measurements from ice cores
• The steep upward trend began around 1850, the
beginning of the industrial revolution

10. 2. The amount of CO2 in our atmosphere
is increasing
• These are direct measurements, made in Hawaii since 1958
• Last year the level reached 400 ppm

11. 3. We are responsible for the rising levels
of CO2 in our atmosphere
Sources of CO2:
• Electricity generation, especially coal-powered
power plants
• Transportation
• Industrial sources (manufacturing)
• Agriculture (deforestation)

12. What is the Evidence for Climate
Change?

13. Evidence for Climate Change
• Thinning of Greenland ice cover
• Retreat of mountain glaciers
• Melting permafrost
• Rising sea levels
– From melting ice
But mostly, as
water warms it
expands

14. Evidence for
Climate Change
• Loss of arctic sea ice
• Problem: this will
have feedback
consequences
– Ice reflects sunlight
back to space
– Liquid water absorbs
sunshine and warms
up
• Affect on ocean
currents?
• Loss of polar bear
habitat

15. Evidence for Climate Change –
Flora and Fauna
• Too many to list!
• Shift to timing of life cycle events
– Earlier budding of trees
– Bird migration earlier
• Shift to range boundaries
– Butterflies have shifted their range 200 km northward in Europe
– Shift of tree lines
– Flagstaff “island in the sky”
• Pinion-Juniper –to – ponderosa pine – to – alpine tundra
• Zones defined by altitude, are shifting up
• A local example: Bark Beetles

16. Bark
Beetles
• British Columbia has lost 33 million acres
of lodgepole pines
• Colorado and Wyoming have lost > 3
million acres
• Due to drought and bark beetle
infestation
• Longer warmer summers -> reproductive
cycle reduced from 2 years to 1 year

17. The Role of Earth’s Oceans
• Earth’s oceans have already absorbed a
significant amount of CO2 and heat
• The oceans are more acidic now – with unknown
consequences for ocean life
• The oceans are warmer now – displacing species?
• More fresh water introduced at the north pole as
the arctic ice sheet melts
• What will be the effect on the oceans’ currents?

18. • Thermo (temperature) – haline (salt content, which affects density)
• The oceans currents are driven by temperature and salt content – both of
which are affected by climate change

19. What are the consequences for the
Future?
• This is where the most uncertainty is…
• If the global temperature rises a few degrees is that
really so bad?
– It’s the energy -> more intense storms
• Too much water in some places, too little in others
– Most important resource we need to manage
• Probably the biggest threat is to the world food supply

20. What will happen in the future?
• Three possibilities
– We stabilize the CO2 levels in our atmosphere
• Consequences we can live with
– We continue to put CO2 into the atmosphere
• Global average temperature will continue to rise
• More severe consequences
– We continue to blithely put CO2 into the
atmosphere and trigger a tripping point
• Likely catastrophic for civilization – food supply
collapse, political chaos

21. Mis-information
• “This is a natural phenomena that has happened
before”
– Yes, but never at this rate
• “China needs to be a part of the solution”
– Well yes, but American’s carbon footprint is far higher
per capita than the chinese
• “This is a hoax for scientists to get funding”
– We need scientific literacy
• An inconvenient truth…

22. • This chart triggered a great deal of skepticism about climate
change…
The Controversy

23. We need data
• (Note historic record)

25. The Solution: We have the
technology…
• Most important – wean ourselves from coal
– Solar power
– Geothermal power
– Wind power
• Cut back on use of fossil fuel for transportation
– Fuel efficient vehicles
• Energy efficient appliances
Natural gas is good if there
are no leaks in pipelines
No more of these!

26. The Solution: We have the
technology…
• CO2 removal at the source (power plants)
• Pull CO2 out of the atmosphere
– Very costly
• Re-forestation
• Carbon limits and markets

27. The War on Coal
• Yes, this is one of the most important
solutions
• But it is an unfortunate consequence for
states that rely heavily on coal for jobs
• As a country we should help those states find
other industries to employ people

28. A Family Values Issue
• The impact will be on our children and
grandchildren
• There are many uncertainties, but …
• Do we really want to experiment with our
children’s future?

29. The
Importance of
STEM
• We all need to be
scientifically literate
• There are numerous
policy decisions to be
made in the upcoming
years with regard to
resource management
and mitigation of
coming changes to our
environment
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