Announcements

• Tuesday Jan 25, 2011: Added links to the class blog, and to Steve's blog.
• Wednesday Jan 12, 2011: Hope you all enjoyed the first class. I've posted the graphs I showed down below...
• Wednesday Jan 5, 2011: Draft course outline posted. Comments welcome!.

About the Course

This course will examine the role of computers and software in understanding climate change. We will explore the use of computer models to build simulations of the global climate, including a historical view of the use of computer models to understand weather and climate, and a detailed look at the current state of computer modelling, especially how global climate models are tested, what kinds of experiments are performed with them, how scientists know they can trust the models, and how they deal with uncertainty. The course will also explore the role of computer models in helping to shape society’s responses to climate change, in particular, what they can (and can’t) tell us about how to make effective decisions about government policy, international treaties, community action and the choices we make as individuals.

The course will take a cross-disciplinary approach to these questions, looking at the role of computer models in the physical sciences, environmental science, politics, philosophy, sociology and economics of climate change. However, students are not expected to have any specialist knowledge in any of these fields prior to the course.

General Course Resources

• Course Information Sheet
• Our Course blog (and a direct link to the login screen)
• Steve's blog
• General info on 199 courses from Arts and Science
• How to avoid plagiarism (a computer science perspective)
• How to avoid plagiarism (a faculty of arts and science perspective)

Seminar Notes & Weekly Readings

All teaching materials on this website are available for use under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License, except where noted otherwise. Links to journal articles should work from anywhere on campus, via the U of T institutional subscription - let me know if they don't. Please respect the copyrights on all material on this site.

As a seminar course, we can be very flexible in what we cover. I've planned a set of core topics that focus on climate models and how they are used, but we can explore much more widely than this if we like.

Core topics:

Part 1: Background & History

• Week 1: Climate Science BC (Before Computers)
  • Jan 11: Fourier, Tyndall, Arrhenius, and The Discovery of Global Warming
  • Additional notes: See Spencer Weart's account of the discovery of the Greenhouse Effect;
  • Here's the video of the experiments demonstrating that CO2 absorbs infrared radiation that I mentioned in class;
  • Here's the figures I showed:
    • Arctic Temperatures for the past 2000 years (from NCAR);
    • Global temperature time series (from IPCC AR4 WG1 Chapter 1);
    • Reconstruction of 800,000 year temperature record (Hansen et al, 2011, figure 2d,e)
    • Reconstricution of 500 million year temperature record (from wikipedia)
    • Slides on key people in the early history of climate change (from Steve's blog)
    • Growth of carbon emissions (from wikipedia)
  • More stuff from Thursday's tutorial:
    • The survey we did was from the Six Americas study
    • Components of the Climate Change Process (from IPCC AR4 WG1 Chapter 2)
    • A schematic of incoming and outgoing radiation (from Prof Bagenal's class at U Colorado)
    • Evidence of Absorption bands for Greenhouse Gases (see: the spectrum, and Harries 2001, also discussed here)
    • Change in Radiative Forcing (from IPCC AR4 SPM)
  • Background on key people from this week:
    • Joseph Fourier - discovered the greenhouse effect, 1820s
    • John Tyndall - first experimental demonstration of the greenhouse effect, 1850s
    • Svante Arrhenius - first calculation of climate sensitivity, 1890s
    • Roger Revelle - discovered oceans absorb much less CO2 than was previously thought, 1950s.
    • Charles David Keeling - set up the first systematic measure of CO2 concentrations, 1960s onwards
• Week 2: Taming Chaos
  • Jan 18: Bjerknes, Lorenz, and the basic equations for modeling the atmosphere, with a gentle introduction to Chaos theory.
  • Additional notes:
    • Basic energy balance model (from IPCC AR4 WG1 FAQ1.1)
    • Where will the energy go? (from the SERC portal)
    • An introduction to Hadley Cells and Rossby Waves (from Youtube)
    • Weather in a tank: experiment1 and experiment2 (from Youtube)
    • Vilhelm Bjerknes - formulated the primitive equations for weather prediction, 1900s
    • Toowoomba Flood, Jan 10th, 2011 (from Youtube)
    • Edward Lorenz - discovered chaos theory, late 1950s
    • The population dynamics formula we talked about in class (from wikipedia)
    • My Excel Spreadsheet for playing with the formula, and the bifurcation diagram
    • Ocean Dynamics visualisation (from GFDL. Try the Avi or Mpg versions first)
    • Cloud and Precipitation Visualization (from NCAR. We looked at the simulation for August)
• Week 3: The Giant Brain
  • Jan 25: von Neumann, Charney, ENIAC and the first general circulation model
  • Here's the figures I used in class this week:
    • An artist's impresstion of Richardson's Forecast Factory (from University College Dublin)
    • A re-assessment of the numbers in Richardson's Forecast factory (From Peter Lynch)
    • A schematic of how modern Global Circulation Models work (origin unknown)
    • A movie explaining the basics of Earth System Modeling (from IPSL in Paris)
    • Some papers on the ENIAC forecast (from Steve's blog)
    • PHONIAC (from Peter Lynch)
    • Graph showing increase in computing power according to Moore's Law (from the wikipedia entry for Moore's Law)
    • Graph showing supercomputing milestones (from AMD's corporate blog)
    • a photo of IBM's Blue Gene (from an interesting article on energy efficient supercomputers at Treehugger)
    • photos of an old Cray and the newer Cray Kraken (from Wired Magazine and Softpedia respectively)
    • The list of the world's fastest supercomputers, from Top500.org
    • Interactive treemap visualization of the world's fastest supercomputers (from the BBC; be sure to check out Canada's fastest...)
    • A diagram explaining the increasing resolution of the models (from the UK Hadley Centre)
    • Increasing resolution of climate models over the four IPCC assessments (from the IPCC AR4 WG1, chapter 1)
  • Background on key people from this week:
    • Lewis Fry Richardson - first numerical weather forecast
    • John von Neumann - designed the first digital computer & assembled a team for the first computer weather forecast
    • Jule Charney - key figure in creating the ENIAC forecasts, later chaired the first US commission that warned of the dangers of climate change.
  • Finally some overviews of geoengineering proposals:
    • Schematic of the main proposals (from an article at Lawrence Livermore Labs)
    • Another schematic with more details on cost, timescale and likely effectiveness (from Next Nature)
    • Alan Robock's article 20 Reasons Why Geoengineering May Be a Bad Idea
    • More resources on Geoengineering (from Steve's blog)

Part 2: What do we know, and how do we know it?

• Week 4: Any Questions?
  • Feb 1: What kinds of questions can we answer with the models? Plus a broader look at the role of science and politics in resolving key questions about climate change.
  • Some basic science questions that need observational data:
    • Graphs of recent temperature change (from the NASA GISS website; for an in-depth analysis see the 2010 paper by Hansen et. al.)
    • Photos of extraction of ice cores (from the NASA Earth Observatory website, as part of an explanation of paleoclimate studies)
    • The Keeling Curve of CO2 concentrations (from NOAA. See also this wonderful animation)
    • Radiative Forcings, 1850-2000 (from IPCC AR4, WG1, Chapter 2. The second graph is the relevant one. It clearly shows the short-lived influence of volcanoes, along with the long term trend in Long-lived Greenhouse Gases)
    • Greenhouse Gas Emissions by Industrial Sector (from the UN Guide to carbon neutrality - loads of great charts here!)
    • Global temperature time series (from IPCC AR4, WG1, Chapter 1)
  • A reminder about what kinds of models are available:
  • A basic energy balance model and a general circulation model
  • A schematic of different types of model (from Moss et al, Nature, 11 February 2010)
  • Image of the Parallel Climate Model (from International Science Grid This Week, image originally from NCAR)
  • Some experiments that can be done with models:
    • Turn off anthropogenic emissions through the 20th Century (from IPCC AR4, WG1, chapter 9. Explanation here)
    • Run simulations of future temperature response to difference emissions scenarios (from IPCC AR4, WG1, chapter 10)
    • But note: there are different ways of showing the results
    • A little explanation of how the experiments are done (from IPCC AR4, WG1, chapter 10)
    • Run simulations of future precipation, soil moisture, runoff and evaporation (from IPCC AR4, WG1, chapter 10)
    • Explore the impact of climate change on the frequency of extreme weather events (from IPCC AR4, WG1, chapter 9)
    • Evaluate the probable values for equilibrium climate sensitivity (from IPCC AR4, WG1, chapter 10)
    • Answer questions such as "how do we keep below +2°C of warming?" (from Allen et al, Nature, 30 April 2009. See also trillionthtonne.org)
    • Calculate possible emissions pathways to avoid +2°C of warming (from Steve's blog, image originally from the Copenhagen Diagnosis)
    • Explore the nature of climate feedbacks (but note, it's really hard to predict where the tipping points are)
  • And some things boil down to value judgments and cannot be answered by science:
    • Should we judge who is to blame for climate change based on current emissions figures? (from the Guardian)
    • Should be looking at emissions per capita rather than per country? (from GapMinder)
    • Should we applaud the developed nations for big cuts in emissions last year, or ignore it because it was probably due to the recession?
    • Should we take into account past emissions? (you can explore this data at GapMinder)
    • Is +2°C an appropriate target to aim for? (from Steve's blog)
    • Should the least developed countries still get their chance to industrialize? (from the Copenhagen Prognosis)
• Week 5: Planetary Boundaries
  • Feb 8: How are we affecting various planetary systems, and how do we figure out what a safe operating space is for humanity? How do policymakers decide on suitable targets for climate policy?
  • Here's the slides I used in class this week:
    • Ten planetary boundaries (from the Tällberg Forum; see also a good blog post giving an overview of talks and commentary on planetary boundaries; and the special issue of Nature where the papers were published)
    • The "how do we keep below +2°C of warming?" experiment (from Allen et al, Nature, 30 April 2009. See also trillionthtonne.org)
    • Growth of carbon emissions (from wikipedia)
    • Growth of atmospheric concentrations of greenhouse gases ( IPCC AR4 WG1 FAQ 2.1, Figure 1)
    • My thought experiment graphs (what happens to concentrations and temperatures for different shaped emissions profiles? - for more background, see John Sterman's experiments)
    • 2°C as an important threshold and how it might relate to climate tipping points (taken from Ramanathan and Feng)
    • Getting back below 350ppm (with a better explanation, Understanding 350 and 350 Science at the 350.org website)
    • Photos from the 350.org campaign: (1) A human sunflower, (2) Divers in the Maldives, (3) Done with fireworks, (4) At a protest rally
    • A Trillion Tonnes of Carbon (cover from the special issue of Nature)
    • Possible emissions pathways to avoid +2°C of warming (from Steve's blog, image originally from the Copenhagen Diagnosis)
    • Another look at current emissions figures (from the Guardian)
    • Another look at past emissions (from GapMinder)
    • What an equal lifetime emissions ration would look like (from a talk by Ray Pierrehumbert)
    • What some key countries might get under such a scheme (from the Copenhagen Prognosis)
• Week 6: Avoiding Dangerous Climate Change
  • Feb 15: Where do greenhouse gas emissions come from, how do we cut down, and can we do it fast enough?
  • Here's the slides I used in class this week:
  • Schematic of the systems of interest - earth systems and human systems (from IPCC AR4 Synthesis Report, Intro)
  • A reminder of 3 different kinds of targets:
  1. Keep emissions below 1 trillion tonnes cumulative emissions (ever)
  2. Get concentrations back down to 350ppm
  3. Keep temperature changes to below +2°C (or below +1.5°C, as some have advocated)
  • A reminder of where Greenhouse Gas Emissions come from (by Industrial Sector) (from the UN Guide to carbon neutrality)
  • A simpler breakdown of emissions by industrial sector (from IPCC AR4 WG3 chapter1)
  • One way of breaking down the challenge - the stabilization triangle (from Princeton U's Carbon Mitigation Initiative)
  • ...and the idea of stabilization wedges (from the same place)
  • but of course, emissions stabilization isn't enough, so we need more wedges (analysis from National Geographic - see also the learn more section)
  • To explain that each wedge starts small and builds over 50 years (from the presentation at CMI)
  • Another view of a set of possible stabilization wedges (from Stenger's blog)
  • Where we waste energy - an example of how much energy it takes to power a lightbulb (from IPCC AR4 WG3 chapter 4)
  • Passive Houses - houses that need no heating system (from the Wikipedia entry on Passive Houses)
  • Electric Cars: The Toyoto Prius, a hybrid electric vehicle, and the Chevvy Volt, a plug-in hybrid electric vehicle
  • But batteries have a long way to catch up with the energy density of petroleum & Diesel (from Toyota's analysis)
  • And the Moore's law for battery technology is much slower than for computers - doubling every 10 years (from a comparison by Kevin Kelly)
  • So we also need to look at changing how people travel (from IPCC AR4 WG3 chapter 5)
  • And if we can't achieve a massive switch away from fossil fuels across all industry and agriculture, what else can we do? Is geo-engineering viable? (a longer look at this material from week 3):
    • Schematic of the main proposals (from an article at Lawrence Livermore Labs)
    • Another schematic with more details on cost, timescale and likely effectiveness (from Next Nature)
    • Alan Robock's article 20 Reasons Why Geoengineering May Be a Bad Idea
    • More resources on Geoengineering (from Steve's blog)
  • And finally, to lighten the mood, a fun video:
  • The Blue Man Group does Global Warming

(Break for reading week)

Part 3: Choosing and Using Models

• Week 8: Experiments, Models, and Modeling Experiments
  • Mar 1: Experiments with CO2, and Experiments with simulation models
  • Here's the videos of experiments I used:
    • Dan Miller's CO2 and ink demonstration
    • Ian Stewart's experiment with an infra-red camera and a candle
    • An experiment that claims to debunk global warming for $5 (check you understand what's wrong with this experiment)
    • Linda's first CO2 experiment (why is her experiment not doing what she thinks it's doing?)
    • Global warming in a jar (a better experiment, but are there still flaws?)
    • Mythbusters do it on a grander scale (but is there anything wrong with their experiment too?)
  • And here's the slides I used about models and experiments:
    • A ridiculously simple model - the bathtub (from National Geographic)
    • The bathtub simulator - have a play! (from Climate Interactive at MIT. See also the Momentum Simulator, and for more explanation see this short paper and a longer one from John Sterman)
    • putting together a model of the globe (as a jigsaw puzzle)
    • A schematic of the main relationships we might want to model (from Flickr user ClimateSafety)
    • Basic energy balance model (from IPCC AR4 WG1 FAQ1.1)
    • A schematic of the different timescales we might be interested in (from McGuffie & Henderson-Sellers, 2005, p74)
    • A schematic of different processes on both time and spatial scales (from Prof Dudley Chelton)
    • Another view of the hierarchy of model types (from McGuffie & Henderson-Sellers, 2005, p51)
    • Another schematic of different types of model (from an overview by David Kemp)
    • A comparison of climate and integrated assessment models (from Moss et al, Nature, 11 February 2010)
    • A reminder of how general circulation models work (from CMMAP's primer)
    • A single column model, which can be compared with single column measurements (from ARM)
    • The Bretherton Diagram: a conceptual model of earth system processes
    • A diagram explaining the increasing resolution of the models (from the UK Hadley Centre)
    • Increasing resolution of climate models over the four IPCC assessments (from the IPCC AR4 WG1, chapter 1)
    • Development of climate models to include more earth system processes (from CSIRO's overview)
    • Architecture of a coupled climate model (from Easterbrook and Johns, 2009)
    • Example coupled model: The Community Earth System Model (CESM)
    • Simpler model for running on a desktop: Educational Global Climate Model (EdGCM)
    • Example Integrated Assessment model: Climate Rapid Overview and Decision Support (C-ROADS)
    • Simplified version, runnable in a web browser: C-Learn
  • For more background on models, see:
    • Modeling the Climate System (chapter 3 of the online textbook by Goosse et al)
• Week 9: Experimentation
  • Mar 8: How to run a model
  • Here's the visualization of the growth of CO2 that we watched:
    • Time history of atmospheric CO2 (from NOAA; see also the latest CO2 measurements)
  • We spent most of the seminar getting familiar with EdGCM:
    • EdGCM website
    • EdGCM tutorial notes
• Week 10: How good are the models?
  • Mar 15: testing, validation, and doing science

Part 4: What we can know, and what we can do

• Week 11: Knowledge and Uncertainty
  • Mar 22: Can we trust the models? Can we predict the future?
  • Well, we didn't get to have this seminar, but here's some things we would have talked about:
    • All models are wrong, but some are useful (a famous quote by George Box, here illustrated by Calvin and Hobbes)
• Week 12: Decisions, Decisions, Decisions
  • Mar 29: What policymakers need, and what they get.
• Week 13: Enough talk, time for action!
  • Apr 5: Managing the Earth's systems - what should we be doing about climate change, and what other tools do we need to be successful?

Additional Topics:

We can include any of these based on interest and enthusiasm (but probably not all of them!). Some of these stray away from the "computing" them of the course, so we might need to agree on some criteria for which ones to include. In no particular order:

• Carbon calculators (and other software for personal/community decision support);
• Data Collection for weather and climate: how the global observing system works;
• Supercomputers and the path to exascale computing;
• Media potrayals of climate models and their projections;
• The role of Free/Open source software in climate science;
• The carbon footprint of computing
• Other sources of evidence about climate change: paleoclimate, observational data, measurable impacts
• Controversy and disinformation - how do you know who to trust? Is there really a debate, and if so, what about?
• How bad will it get?
• Climate Change and other global issues: over-population, peak oil, conservation of ecosystems, international conflict, food security, renewable energy, etc.
• Geo-engineering
• Climate Ethics: inter-nation and inter-generational issues

Assignments

There are four assignments for the course:

1. Research a topic related to the course and write a blog post about it. Due Jan 28th. Worth 15%
• The blog is here
• See detailed criteria for your blog posts.
2. Prepare a 10-minute power point presentation (in teams of 2). Due Feb 18th. Worth 20%
• See detailed instructions on the class blog
3. Design an experiment. Due March 18th. Worth 15%
• See detailed instructions on the class blog
• pointers to example models
4. Final Essay. Due April 7th. Worth 40%
   • Detailed instructions coming soon

Plus 10% of the course mark is for showing up for seminars and tutorials, and participating in the class blog (as you asked for it!)