Today (Tues 3/3)

1
Today (Tues 3/3)

• Chapter 2 Homework Due
• Newspaper Articles Jeremy Hendrickson and Matt
  Wood
• Molecular Shape Activity
• Start Chapter 3 notes
• Laboratory Greenhouse Gases Lab

2

Review How to draw Lewis structures
1. Determine the sum of valence electrons.
CH4
CCl4
C 4 Valence electrons H 1 Valence electron 4
atoms Total 8 electrons
C 4 Valence electrons Cl 7 Valence electron 4
atoms Total 32 electrons

1. Use a pair of electrons to form a bond between
   each pair of bonded atoms.

Cl
Cl
Used 8 in each
Cl
Cl

1. Arrange the remaining electrons to satisfy octet
   rule.

..
Cl
..
..
..
..
Cl
Cl
Used 8
..
Used 32
Cl
3
Molecular Shape Activity
4
Fig. 3.11 Carbon Dioxide
Lewis structuresshow connectivity.
Space-filling Charge- density

5
Fig. 3.8 - Methane
This Lewis structure is drawn in 3-D.
6
Figure 3.9 Ammonia
7
Fig. 3.10 - Water
8
Nitrate Ion, NO3-
9
Fig. 3.12 - Ozone
10
Summary of Molecular Shape Activity Valence
Shell Electron Pair Repulsion Theory

• Assumes that the most stable molecular shape has
  the electron pairs surrounding a central atom as
  far away from one another as possible.
• Molecules can be classified into shape
  categories.
• If there are lone pairs on the central atom, the
  bond angles will be smaller than predicted.

11
Chapter 3 The Chemistry of Global Warming
12
Chapter 3 Learning Objectives

• The greenhouse effect
• Molecular structure and shape
• Why are some molecules greenhouse gases (absorb
  IR radiation)
• Molecular vibrations
• Moles
• Enhanced Greenhouse Effect andGlobal Climate
  Change
• Global Climate Change Models
• Global Climate Change Policy

13
The Earths Energy Balance
Greenhouse effect Our atmospheric gases trap and
return a major portion of the heat radiating
from the Earth. It is a natural, necessary
process.
Figures Alive
14
What makes a gas a greenhouse gas?

• IR absorption is related to molecular structure
• Dipole moment separation of charge
• Electron density is not uniform in the molecule
  resulting in partial electrical charges

15
Which of the following molecules have a dipole
moment? H2O, CO2, O3, and CH4
16
To absorb IR radiation

• Energy of IR radiation must match the vibration
  energy of the molecule
• For us to see absorbtion of IR radiation on a
  spectrometer the dipole moment (charge
  distribution) must change
• IR Tutor
• Units on IR spectra are wavenumbers, cm-1
• Wavenumber 1/wavelength (in cm)

17
Fig. 3.14 IR spectra of CO2
18
Fig. 3.15 IR spectra of H2O
Stretching
Bending
19
Why arent O2 and N2 greenhouse gases?
Why doesnt the IR radiation coming from the sun
also cause a greenhouse effect?
20
Today (Thurs 3/5)

• Newspaper Articles Eric Noun and Steve Andres
• Chapter 3 notes review and new
• Focus Group project Evaluation of Example
  Papers

21
Chapter 3 Learning Objectives

• The greenhouse effect
• Molecular structure and shape
• Why are some molecules greenhouse gases (absorb
  IR radiation)
• Molecular vibrations
• Moles
• Enhanced Greenhouse Effect andGlobal Climate
  Change
• Global Climate Change Models
• Global Climate Change Policy

22
The Earths Energy Balance
Greenhouse effect Our atmospheric gases trap and
return a major portion of the heat radiating
from the Earth. It is a natural, necessary
process.
Figures Alive
23
(No Transcript)
24
What makes a gas a greenhouse gas?

• IR absorption is related to molecular structure
• Dipole moment separation of charge
• Electron density is not uniform in the molecule
  resulting in partial electrical charges

25
Which of the following molecules have a dipole
moment? H2O, CO2, O3, and CH4
dipole moment
dipole moment
no dipole moment
no dipole moment
26
To absorb IR radiation

• Energy of IR radiation must match the vibration
  energy of the molecule
• For us to see absorbtion of IR radiation on a
  spectrometer the dipole moment (charge
  distribution) must change
• Units on IR spectra are wavenumbers, cm-1
• Wavenumber 1/wavelength (in cm)

27
Fig. 3.14 IR spectra of CO2
28
Fig. 3.15 IR spectra of H2O
Stretching
Bending
29
The Greenhouse Effect

• Established
• Proven
• Fact
• Not controversial
• Temperature of the earth would be 60 F cooler
  without the Greenhouse Effect
• Global Warming is the theory that the greenhouse
  effect has been enhanced by carbon dioxide and
  other greenhouse gases

30
Amplification of Greenhouse Effect Global
Warming What we know
1. CO2 contributes to an elevated global
temperature.
2. The concentration of CO2 in the atmosphere has
been increasing over the past century.
3. The increase of atmospheric CO2 is a
consequence of human activity.
4. Average global temperature has increased over
the past century.
3.2
31
What might be true
1. CO2 and other gases generated by human
activity are responsible for the temperature
increase.
2. The average global temperature will continue
to rise as emissions of anthropogenic greenhouse
gases increase.
3.8
32
Loss of Polar Ice Cap
NASA Study The Arctic warming study, appearing
in the November 1 2003 issue of the American
Meteorological Society's Journal of Climate,
showed that compared to the 1980s, most of the
Arctic warmed significantly over the last decade,
with the biggest temperature increases occurring
over North America.
1979
2003
Perennial, or year-round, sea ice in the Arctic
is declining at a rate of nine percent per
decade.
3.9
33
Loss of Polar Ice Cap
1979
As the oceans warm and ice thins, more solar
energy is absorbed by the water, creating
positive feedbacks that lead to further melting.
Such dynamics can change the temperature of
ocean layers, impact ocean circulation and
salinity, change marine habitats, and widen
shipping lanes.
2003
3.9
34
The snows of Kilimanjaro
82 of ice field has been lost since 1912
3.9
35
Main greenhouse gases

• Water vapor
• Carbon dioxide
• Methane
• Chlorofluorocarbons (CFCs)
• Tropospheric ozone
• Nitrous Oxide N2O

36
Carbon Cycle
Fig. 3.17
37
Fig. 3.4
CO2 and Temperature
38
McMurdo Station, Antartica
Ice Core
Ice Layers
Drilling Tent
39
CO2 concentrations by ice core and IR data
Fig. 3.5
40
Cool Links

• IR spectra of CO2 and other GHGs

http//chemistry.beloit.edu/Warming/pages/infrared
.html

• NOAA National Oceanic and Atmospheric
  Administration
• Measuring CO2
• Ice Core Data
• Oceans Warming

http//www.esrl.noaa.gov/gmd/ccgg/about/co2_measur
ements.html
http//www.ncdc.noaa.gov/paleo/icecore.html
http//www.noaanews.noaa.gov/stories/s399.htm

• National Glaciology Group, Canada

http//cgc.rncan.gc.ca/glaciology/national/drill_e
.php
41
CO2 trends

• CO2 increasing 2.1 ppm/yr (for 2001-2005)
• 1963 increase 0.76 ppm
• 1998 increase 2.87 ppm (biggest leap)
• 2002 increase 2.1 ppm
• 2007 increase 2.4 ppm

http//www.esrl.noaa.gov/gmd/publications/annmeet2
006/pdf_2006/talks202006202.pdf
42
Today (Tues 3/10)

• Newspaper Presentations Brock Hill and Andrew
  Griesman
• GHGs and IR Spectra (Lab Prep)
• Library Time (3-420)

For Next Time (Thurs 3/12)

• Print new slides (I added some to the end)
• Read Chapter 3
• Work on Homework 3

43
Why is CO2 increasing?

• Burning fossil fuels converts the carbon in the
  fuels to carbon dioxide (CO2)
• Fossil fuels coal, gasoline, natural gas
• Actually CO2 levels have not increased in the
  atmosphere as much as predicted
• Also been contended that CO2 levels have
  increased due to temperature increasing
• Scientific understanding is key models developed

44
CO2 IR Spectra
45
Tab. 3.2
46
Methane

• Sources
• 40 Natural Sources
• Natural Gas escaping from rocks
• Decaying plant material in wetlands
• Agriculture
• Rice Paddies (Anaerobic Bacteria)
• Cattle (500 L of CH4 per day!)
• Landfills
• Termites
• Release from oceans, bogs, permafrost

47
IR Spectra of Methane
CO2 Contamination
48
Laughing Gas, N2O

• Sources
• Bacterial removal of nitrate ion (NO3-) from
  soils
• Ocean upwelling
• Statrospheric reactions
• NH3 fertilizers
• Catalytic converters

49
IR spectra of Water vapor
CO2 Contamination
50
IR Spectra of some GHGs
51
Tab. 3.3
The bigger the number, the greater the effect.
52
Today (Thurs 3/12)

• Newspaper Articles Tom Jaede
• Can we have global cooling?
• Global Climate Change Models
• Global Climate Change Policy
• Group Activity

For Next Time (Tues 3/17)

• Finish reading Chapter 3
• Homework 3 Due
• Start studying for the exam (on 3/19) bring
  questions to class!

53
Aerosols and Particulates

• Aerosol small atmospheric particle can be a
  solid particle, liquid suspension, or combination
• Subject to Brownian motiondont settle for a
  long time. ( unlike bigger particles which settle
  out quickly).
• Coal combustion sulfates
• Sulfates seed condensation clouds
• Aerosol particles and clouds reflect incoming
  radiation - this is a cooling effect
• However, some aerosols are black and absorb
  radiation

54
Volcanoes

• Mt Pinatubo in Phillipines erupted in 1991
• 20 million tons of sulfur dioxide and
  particulates into the stratosphere
• Particulates reflected sunlight in the
  stratosphere before the radiation got to the
  troposphere.
• Cooled the planet for 2 years.

55
Aerosols

• In conclusion they act to cool the globe.
• We produce a lot of them
• Earlier models predicted warmer climates than we
  are seeing
• Aerosols are off-setting some effects of the
  increase in greenhouse gases.

56
Modeling Global Warming
57
Climate Forcing

• A relatively simple way to look at climate change
• Climate Forcing an imposed perturbation on
  the earths energy balance
• Positive forcing adds energy creates warming
• Negative forcing reduces energy leads to
  cooling
• Climate models predict
• Forcing of 1 W/m2 3/4oC (equilibrium)
• This relation consistent with last Ice Age
• James Hansen (NASA)
• http//naturalscience.com/ns/articles/01-16/ns_jeh
  .html

58
Climate forcing agents in the industrial era
(18502000) (W/m2).
59
Pinatubo
El Chichon
60
Fig. 3.22
61
Worldwide Emissions and Policies
62
Fig. 3.23
Good Source for Additional Data
http//cdiac.ornl.gov/trends/emis/meth_reg.html
63
Fig. 3.27
64
Page. 147.2
65
Policy History

• 1988 IPCC (Intergovernmental Panel on Climate
  Change) established by World Meteorological
  Organization (WMO) and the United Nations
  Environment Programme (UNEP)
• 1992 Earth Summit
• 1997 Kyoto Conference
• 2007 IPCC states in a report that scientific
  evidence for global warming was unequivocal and
  that human activity is the main cause.

66
What IPCC Does

• Run from offices in Geneva, but open to any of
  the nearly 200 member states belonging to the UN
  or WMO
• Functions through its working groups focusing on
  the science, impact and mitigation of climate
  change, and developing greenhouse gas
  inventories.
• The findings of the IPCC are presented as
  'Assessment reports', synthesizing the views of
  the working groups, which are produced
  approximately every 5 years.
• The fourth and next report is due at the end of
  2007.

Back
67
Nobel Peace Prize 2007

• http//www.ipcc.ch/ipccreports/tp-climate-change-w
  ater.htm

Nobel Peace Prize Laureates Al Gore (left) and R.
K. Pachauri, Chairman of the Intergovernmental
Panel on Climate Change (IPCC) with their Nobel
Peace Prize Medals and Diplomas at the Award
Ceremony in Oslo, Norway, 10 December 2007.
R. K. Pachauri will be at Gustavus for Nobel
2009!
68
The Kyoto Protocol

• 160 nations met in Kyoto Japan in 1997 to
  negotiate the Protocol
• The protocol states that developed nations will
  limit GHG emissions at 5 below 1990 levels (US
  7)
• CO2, CH4, NO, HFCs, PFCs, and SF6
• Short-term goals no long-term fixes (major
  criticisms)
• Emissions could be traded
• Credits for creating carbon sinks? -removed
• U.S. signed the Protocol but would not ratify it
• Kyoto went into effect Feb 16, 2005 w/o the US
  participating

69
Who has ratified - who hasnt

• Protocol went into effect when 55 parties
  representing 55 of heat-trapping emissions have
  ratified
• All 15 nations in the European Union have
  ratified, Canada and Japan
• Russia ratified in November 2004, Protocol went
  into effect in February 2005
• US is responsible for 25 of carbon emissions
• Developed nations emit about 62 of carbon
  emissions

70
What would U.S. have to do to meet emission
requirements

• We could easily reduce emissions by 7 by simply
  conserving, raising fuel mileage stds, increasing
  investment in renewable energy
• US already 13 above 1990 emissions link
• 20 reduction would be required
• Any policy to reduce emissions will have
  significant implications for energy industry and
  the whole U.S. economy. We need more energy
• Commitment period would be between 2008-2012

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(No Transcript)
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back
73
National Policy What has the Bush
Administration Done?

• During 2000 campaign President Bush promised
  mandatory reduction targets for CO2 emissions
• The Kyoto Protocol is fatally flawed India and
  China are not required to do anything the
  Protocol would hurt the economy
• Most future GHG emissions will come from
  developing nations and they arent required to do
  anything! - besides we need to meet future
  energy needs and our economy has become more
  energy efficient
• Kyoto doesnt solve the problem anyways

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(No Transcript)
76
Bush Global Climate Change Initiative

• GHG intensity cut by 18 over next 10 yrs link
• GHG intensity
• GHG emissions allowed to increase by 31 over
  this time (assumes GDP increase is 3.3/yr) GHG
  intensity decreased 17 in the 90s
• This goal is comparable to the avg progress that
  nationsin Kyoto Protocol are required to
  achieve
• Yes, because Kyoto requires nothing of developing
  nations
• as the science justifies
• The data are very clear the earth has warmed
  and considering only extreme weather events, the
  cost to the US was over 40 billion dollars in
  2004

77
GHG Intensity
78
Latest Data from EPA
http//www.epa.gov/climatechange/emissions/downloa
ds09/07Trends.pdf
79
Impacts of Global Warming

• Drought and wildfire due to increased evaporation
• Sea level rise (10-25 cm increase to date 48-95
  cm by 2100) inundation of low-lying areas
• More intense rainstorms and more hurricanes
• Ecological Impacts
• Migration, breeding, population, species
  composition, lakes/fish, forests, coral reefs

80
What would we have to do to curtail warming?

• Burn less fossil fuels
• Increase the cost (carbon tax tax on gas, coal,
  and natural gas burning)
• More efficient vehicles, houses, appliances, etc.
• Use non-carbon based or renewable fuels
• Wind energy, solar energy
• Hydrogen fuel cells
• Ethanol, biodiesel
• Remove CO2 from emissions / atmosphere
• Who is responsible?

81
Group Activity

• To stabilize the current climate, scientists
  estimate an 80 reduction in greenhouse gas
  emissions is necessary
• Within in your group choose one of the three
  scenarios
• Immediate, significant greenhouse gas emission
  reductions
• Gradual reductions of greenhouse gas emissions
• Next, give suggestions for how you would make
  your scenario a reality
• Why do you think this approach is best? What are
  the pros and cons of your approach? Are you free
  to realize the environmental future that you
  envision?

82
Today (Tues 3/17)

• Newspaper Articles Peter Dierauer, Wai Yang
• Discussion Obama Administration
• Finish Chapter 3 notes
• In-class worksheet on Chapter 3
• Lab time Optional Exam Review

For Next Time (Thurs 3/19)
First Exam!!
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Tab. 3.6
84
The Mole
85
The mole

• Avogadros number 6.02 x 1023 of anything per
  mole (anything atoms, molecules, etc.)
• Molar mass or molecular weight is usually
  expressed as grams per mole
• What are the molar masses or molecular weight of
  C and CO2?
• Carbon in CO2-mass ratios and mass

86
Keep these relationships in mind
use molar mass
molecules
grams
use Avogadros number
moles
Remember the critical link between moles and
grams of a substance is the molar mass
ITS SIMPLE THINK IN TERMS OF PARTICLES!
3.7
87
Quantitative Problems

• Cover problems on chalkboard
• What is the molar mass of ammonia, NH3?
• What is the mass ratio and mass of nitrogen in
  ammonia?
• For each mole of CH4 combusted, how many moles of
  CO2 and H2O are formed?
• How many CO2 molecules are formed when one mole
  of CH4 is combusted?
• There are 2.4 kg of C in a gallon of gasoline,
  how much CO2 is emitted from your tailpipe when
  you burn 1 gallon of gasoline?
• My car gets 20 miles/gallon. If I drive 10,000
  miles a year, how much C (in kg) is emitted each
  year?

My car weighs 2000 kg!
88
Quantitative Problems

• Answers to problems on chalkboard
• 17.034 g/mol
• 0.822 g N per g NH3 or 82.2 N in NH3
• For 1 mole of CH4 combusted, 1 mole of CO2 and 2
  moles of H2O are formed
• 6.02 1023 molecules of CO2
• 8.8 kg CO2
• 1200 kg C

My car weighs 2000 kg!