Transcript ClimateChange1

Climate Change, and the
Scientific Process
Let’s review last week: sometimes Venus, Earth and
Mars are called the Goldilocks planets
Compare these Three:
Venus
Earth
Mars
Temp at surface
880 F
59 F
-58 F
Pressure at surface
~ 90 atmospheres
1 atmosphere
(14.7 lbs/sq in)
0.007 atmospheres
Atmosphere
composition
CO2 and sulfuric
acid clouds
Nitrogen, oxygen,
water vapor clouds,
CO2, nitrogen
Dist. from sun
0.7 A.U.
1 A.U.
1.5 A.U.
One word description?
Let’s look at atmosphere more carefully:
Venus
Earth
Mars
Carbon Dioxide:
96%
Nitrogen: 78%
Carbon Dioxide:
95%
Nitrogen: 3.5%
Oxygen: 21 %
Argon: 0.9%
Water: > 1%
Carbon Dioxide:
0.004% *
Nitrogen: 3%
Argon: 2%
How did Venus get so hot?
A planet with an atmosphere
Solar
radiation
comes in
The greenhouse gases
reradiate. Some of
the energy goes
towards the surface.
Greenhouse gases
Planetary surface
Planetary
radiation goes
out, but gets
absorbed
In class, or lab exercise: Greenhouse effect
Go to http://phet.colorado.edu/en/simulation/greenhouse
How do greenhouse gases naturally get into the atmosphere?
Water: evaporation
CO2: vaporization of rocks,
release from volcanos,
vaporization of biotic material
(like fossil fuels), respiration
Methane: release from earth,
biology (bacteria, cows, rice)
1. Volcanos brought up gas trapped in rock
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2. Comets hitting the young earth brought
water, water vapor and carbon dioxide.
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3. Earth developed an oxygen atmosphere from plant life
What is happening to the atmosphere today?
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Report on Global
Climate Change –
IPCC 2013*
“Warming of the climate system
is unequivocal, and since the
1950s, many of the observed
changes are unprecedented over
decades to millennia. The
atmosphere and ocean have
warmed, the amounts of snow
and ice have diminished, sea
level has risen, and the
concentrations of greenhouse
gases have increased .”
* Intergovernmental Panel on Climate Change: A total of 209 Lead
Authors and 50 Review Editors from 39 countries and more than
600 Contributing Authors from 32 countries contributed to the
preparation
Articles published in peer review journals support
idea that this is happening, and that it is caused by
humans
Peer review, or refereed: article has been anonymously approved
by another expert in the field before publication
Global warming: a look at the data
These temperatures are derived from different methods
CO2 levels in ppm (parts per million)
Class exercise with Mauna Loa (top of volcano in Hawaii) data:
Plotting some data on the CO2 concentration in the atmosphere
Date
CO2 (ppm)
Each team will plot one
year’s worth of CO2 data
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Group #
______
394
393
392
CO2 Concentration (ppm)
391
390
389
388
387
386
385
384
383
382
381
380
379
378
377
376
2011
July
2010
July
2009
July
2008
July
2007
July
2006
July
2005
July
375
2012
395
Keeling Mauna Loa CO2 Data (2005-2011)
Carbon Dioxide in ppm
390
385
380
375
370
Jan-05
Jan-06
Jan-07
Jan-08
Jan-09
Time
Jan-10
Jan-11
Jan-12
Various effects of climate change today
Summary of effects:
Shrinking ice
sheets
Declining
arctic ice
Melting
glaciers
Sea level
rise
Global
temperature
rise
Warming
oceans
What can we do to reverse this?
Currently, 30% of both the US House and Senate are on
record as denying climate change, or its importance.
Solution requires many nations to address the problem:
China in particular
What can we do…
•Buy more fuel efficient cars and trucks,
do less driving, do more car pooling, use
CFL (compact fluorescent) light bulbs, use
solar cooker…
•Develop Solar power on homes
•Burn less coal (which creates much of
our electricity)
•Develop alternative energy: wind, nuclear
•What are your ideas?
Take away message:
Earth’s temperature is increasing
because carbon dioxide concentration is
increasing.
All evidence is that this is caused by
human activity.
Lecture tutorial, Greenhouse effect
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Index: Change in earth’s temperature
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