Course-Related Readings and Assignments
Class #2-3 (Greenhouse Gases on The Rise):
Readings:
Intergovernmental
Panel on Climate Change (IPCC) Fourth Assessment (“AR4”) Working Group 1
(“WG1”) Report, Summary For Policy Makers, pages 2-3
Assignment:
Write a short (1-2 paragraph) critique of this news
article that appeared in the British newspaper The Scotsman based on your readings and any possible supplementary
sources of information you wish to use
(though note the instructions regarding use of supplementary sources of
information in the course
syllabus)
Class #4-5 (The Greenhouse Effect):
Readings:
IPCC AR4 WG1
Repot, Frequently
Asked Questions,
Question #1.3 “What is the Greenhouse Effect”, pages
6-7
“The Discovery of Global Warming” by Spencer Weart (American Institute of Physics) The
Carbon Dioxide Greenhouse Effect
Assignment:
Use this online
calculator from the University of Massachusetts Geosciences Department to
investigate the impact of
the Greenhouse Effect (you
can ignore the list of questions). In this simple model, the greenhouse
effect is represented by a single
parameter, the fraction of the longwave radiation emitted from the Earth that
is radiated back down towards the surface rather than escaping to space (due to
the ‘greenhouse effect’). The current greenhouse effect is approximated by
assuming that this fraction is 0.40 (i.e. 40%).
Do the following
calculations. Convert all answers from Kelvin to Fahrenheit.
1. The default fraction of the online calculator is 0.397. Change this to
0.40 to estimate the current average
surface temperature of the Earth.
2. What would the average temperature of the Earth be if there were no
greenhouse effect at all? What are the implications of your answer?
3. Assume that doubling of CO2 concentrations relative to their
pre-industrial levels will increase the
back radiation from 40% to 41% (at the
low end of the range that has been calculated by scientists). How much warming will be expected?
4. Assume that instead, this doubling increases the back radiation from
40% to 44% (at the upper end of the
calculated range). Now how much warming would be expected in this case?
Class #5-6 (Humans vs. Nature: The Competing Impacts of
Humans and Nature on Climate):
Readings:
IPCC AR4 WG1
Report Frequently
Asked Questions, Question #2.1
“How do Human
Activities...Compare with Natural Influences?”, pages 8-10 of document
IPCC AR4 WG1
Report Frequently
Asked Questions, Question #6.1 “What caused...climate
changes...before the industrial era”, pages 20-21 of document
Class #7 (Scientific Uncertainty):
Readings:
IPCC Fourth
Assessment Report, WG1 Summary For Policy Makers, table on page 8
RealClimate article: Just what is this consensus anyway?
Assignment:
Read the news article The
Truth About Denial from the August 13 2007 issue of Newsweek magazine. Come to class prepared to participate in a group discussion.
Class #8 (Observations of Modern Climate Change):
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #3.1 “How are temperatures...changing?”, pages 11-12
RealClimate article: The Global Cooling Myth
Assignment:
Perform a google
news search using appropriate key words to determine how many news articles
in the past month (among those listed by google) refer to the claim
that scientists were predicting global cooling in the 1970s. Briefly summarize
your findings. Come to class prepared to
discuss some of the examples you found.
Class #9 (Observations of Modern Climate Change, continued):
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #3.2 “How is precipitation...changing?”, pages 13-14
IPCC AR4 WG1 Report Frequently Asked Questions, Question #3.3 “Has there been a Change in Extreme Events...?”, page
15-16
IPCC AR4 WG1 Report Frequently Asked Questions, Question #9.1 “Can Extreme Events be explained...Greenhouse Warming?”, page
27
Assignment:
Read this BBC article from July 25, Is Extreme
Weather Due to Climate Change? and be prepared to
participate in an in-class discussion of the article.
Class #10 (In-Class
Writing Workshop):
Readings:
New York Times article (Feb 6 2007) “On the Climate Change Beat, Doubt Gives way
to Certainty”
Assignment:
Come to
class prepared to participate in a writing workshop based on the above New York
Times article.
Class #11 (Observations of Modern Climate Change,
continued):
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #3.2 “How is precipitation...changing?”, pages 13-14
IPCC AR4 WG1 Report Frequently Asked Questions, Question #3.3 “Has there been a Change in Extreme Events...?”, page
15-16
IPCC AR4 WG1 Report Frequently Asked Questions, Question #9.1 “Can Extreme Events be explained...Greenhouse Warming?”, page
27
Assignment:
Read this BBC article from July 25, Is Extreme
Weather Due to Climate Change? and be prepared to
participate in an in-class discussion of the article.
Class #12 (Observations of Modern Climate Change,
continued):
Readings:
see class #11
Assignment:
see class #11
Class #13 (A Tempest in a Greenhouse: Have Hurricanes Become
More Frequent or Intense?):
Readings:
RealClimate article: Hurricanes and Global Warming – Is there a connection?
Pew Center on Climate Change, Hurricanes and
Global Warming Q&A
Assignment:
Listen to this video
from the “Forecast Earth” series on The
Weather Channel. Write a 1 or 2
paragraph summary discussing the main point of
scientific contention, interpreting this within the context of the
readings. Come to class prepared to
participate in a debate.
Class #14 (The Paleoclimate Perspective):
Readings:
RealClimate article: What does the lag of CO2 behind
temperature in ice cores tell us about global warming?
RealClimate article: The lag between temperature and CO2
IPCC AR4 WG1 Report Frequently Asked Questions, Question #6.2 “Is the Current Climate Change Unusual......?”, page 22
RealClimate article: Medieval Warmth and English Wine
Class #15 (The Paleoclimate Perspective, continued):
Readings:
see class #14
Class #16 (‘The Day After Tomorrow’: A Possible
Scenario?):
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #10.2 “How Llikely are..Abrupt
Climate Changes......?”, pages 31-32
Assignment:
Read synopses (e.g. here and here) of the movie
‘The Day After Tomorrow’ and view
these traliers and video clips for the movie. Write a brief
(roughly 1 page) assessment of the accuracy of the science and the plausibility
of the scenario outlined in the movie based on your readings. Come to
class prepared to participate in a debate.
Class #17 (Climate Modeling; Can’t we Explain Past Trends by
Natural Factors Alone):
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #1.1 “What Factors Determine Earth’s Climate?”, pages 2-3
IPCC AR4 WG1 Report Frequently Asked Questions, Question #1.2 “What is the Relationship Between Climate and Weather?”, pages
4-5
IPCC AR4 WG1 Report Frequently Asked Questions, Question #8.1 “How Reliable Are the Models...?”, pages 25-26
IPCC AR4 WG1
Report Frequently Asked Questions, Question #9.2
“Can
the Warming...be explained...Natural Variability?”, pages 28-29
Assignment:
Perform a google
news search using appropriate key words to determine how many news articles
in the past month (among those listed by google)
suggest that the warming of the past century is likely to have been due to
natural, rather than human, influences. Briefly summarize your findings. Come to class prepared to discuss some of
the examples you found.
Class #18 (How Sensitive is the Climate?)
Readings:
‘Greenhouse Gas
Effect Consistent Over 420 Million Years’: News
article summarizing research article in Nature
by Royer et al
Assignment:
Reconsider the online calculator
we used earlier in the course (see lecture #3 assignment). We will assume that
a ‘climate sensitivity’ of 1.5 degrees C (that is, a sensitivity such that a
doubling of CO2 concentrations leads to 1.5 degree C warming of the globe)
corresponds to an increase in back-radiation fraction from 0.40 to 0.41 for
doubling of CO2. Also assume that for
each increase in the sensitivity of the climate of 1 degree C, the size of the
increase in the back-radiation factor fo CO2 doubling
grows by 0.01. What range in climate sensitivity is then implied by the
back-radiation fractions that were cited (see lecture #3 assignment above) for
the low-end vs high-end of the estimated range. This
represents the approximate range within scientists believe the true ‘climate sensitivity’
likely lies. How does your calculated climate sensitivity range compare with
the estimates you came across in your assigned readings?
Class #19 (Projections of Future Climate Change: Emissions
Scenarios)
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #10.3 “If Emissions are Reduced, How Quickly do..Concentrations
Decrease...?”, pages 33-34
Assignment:
Read the RealClimate article: Make your own forecasts of future energy,
carbon emissions, and climate and experiment with this simple online
model for carbon emissions scenarios. First, take note of the default
values the three variables (leveling-off value of human population, and rates
of change in GDP/capita, energy intensity, and carbon efficiency,) and run the model
(i.e., click on ‘do the math’) with these default values. Note the trajectories
of the various output variables. Pay particular attention to the set of curves
shown in the plot entitled “Carbon-Free Energy Required for CO2 stabilization”.
This shows how much energy we would need to produce from non carbon-related
forms of energy (e.g. renewals such as wind, solar, and hydroelectric energy,
and nuclear energy) to achieve stabilization of atmospheric CO2 concentrations
at some maximum level. Suppose we decide that it is necessary to stabilize global
CO2 concentrations at 450 ppm to avoid dangerous interference with the climate.
Then the relevant curve is the green curve. This curve shows that we would need
to be able to produce roughly 20 terawatts of energy from non-carbon sources by
2100 to achieve stabilization at 450ppm given the default assumptions in the
model. Now, perform the following exercises:
1. The default value for Energy Intensity rate of change (-1.0) doesn’t
provide a great fit with the observed data (see plot labeled ‘Energy Intensity’).
So play around with the input Energy Intensity rate value, and see if you can
find a value that yields a slightly
better fit to the actual data (hint: the value should be somewhere between -1.0
and 0). If we adopt this value as being more accurate, will stabilization of
CO2 concentrations at 450ppm require a greater or lesser production of
carbon-free energy than calculated above, i.e. will it be easier or more
difficult to achieve CO2 stabilization at 450 ppm? How much carbon-free energy
would be required to meet demands in 2100 in order to stabilize CO2 at 450 ppm?
2. Suppose that it is only possible to produce at most 19 terrawatts from non-carbon energy sources by 2100 (note
that that is 50% larger than 13 terrawatts, the current total rate of global energy
production from all sources). In this
case, we would obviously not be able to
meet the non-carbon energy demands calculated in question 1. Alternatively, we
could meet those demands by stabilizing global population at a lower level than
the default level of 11 billion. What is
this level? Given that the current population is roughly 6.7 billion, do you
think this is a realistic goal?
Class #20 (Projections of Future Climate Change: The Next
Century)
Readings:
IPCC AR4 WG1
Report Frequently Asked Questions, Question #11.1
“Do
Projected Changes...Vary from Region to Region?”, page 35
Class #21 (Projections of Future Climate Change: Melting Ice
and Rising Sea Level)
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #5.1 “Is Sea Level Rising?”, page 19
RealClimate article: The IPCC Sea Level Numbers
Assignment:
Perform a google
news search using appropriate key words to determine how many news articles
in the past month (among those listed by google)
discuss scientific linkage between global warming and observed or future sea level
rise. Skim the first ten or twenty articles that turn up in your search. Do any
of the articles express doubt about future rises in sea level? Do the views
expressed tend to correspond more closely first (IPCC) or second (RealClimate Aritlce) of the two readings? Briefly summarize your
findings. Come to class prepared to
discuss some of the examples you found.
Lecture 22 (In-Class
Internet/Web Workshop):
Instructions will be sent from guest speaker prior to class meeting
Class #23 (Projections of Future Climate Change: Changes in
Extreme Weather)
Readings:
IPCC AR4 WG1 Report Frequently Asked Questions, Question #10.1 “Are Extreme Events...Expected to Change?”, page 30
Lecture #24 (The Science in ‘An Inconvenient Truth’)
Readings:
RealClimate article: Al Gore’s Movie