Jenna Ryon


First Presentation

Questions on the first presentation

  1. What is the method for determining air temperature from sea? Does latitude have an effect?
  2. How well does ocean surface temperature work as a proxy for mean global temperature?
  3. Has any data been taken that does not support the theory that the current climate is a normal phenomenon?
  4. You cited the Vostock ice-core samples as an important piece of information in determining the climate record. Over what geographic range were these or other ice-core samples taken, and could they have been subject to any particular regional biases? Similarly, how reliable are coral and tree-ring records? Are they subject to some kind of normal biological fluctuations? For example, maybe some kind of disease might spread through the population of coral or trees for awhile, hindering growth and blurring the record…
  5. I vaguely recall learning that past periods of high atmospheric CO2 levels were correlated with a complete shutdown of ocean circulation, which in turn caused the deep ocean to become anoxic. Such events were associated with sudden deposition of large amounts of organic matter on the seabed, something which we can observe in sedimentary deposits. I'm curious about evidence for such events in the geologic record, and how they may (or not?) provide hints regarding the future evolution of the Earth's climate, as we continue to pump CO2 into the atmosphere.
  6. I've heard a lot of sources saying that global warming will lead to hotter summers (reasonable) and colder winters (confusing).  What is the reasoning behind the idea that global warming will cause colder winters?
  7. How easily and definitively can ice-core sections be dated?
  8. I'm anxious to see some popular models and why they work/don't work.  For one of your future presentations can you possibly explain how a specific model is developed?
  9. Since it is established that global warming is definitely occuring, what exactly are some of the environmental consequences of global warming? It'd be nice to have some of the myths about the consequences of global warming dismissed. Since clouds are the big uncertainty in the current climate models, learning more about clouds would be interesting.
  10. Can you talk more about how much we can get out of the correlations from ice, tree, coral cores?  In other words, what predictions are we actually able to comfortably make?
  11. For tree rings, how do they take out which variable is affecting the ring?
  12. How much of the huge scare revolving around climate change is justified?
  13. How likely is it that we can reverse the climate change trend, and what measures will have to be taken to accomplish that reversal?

Second Presentation

Paper References

Paper Outline


  • Motivation to study of climate change
  • Short history of how discovery of climate change came about?
  • Paragraph overview of rest of paper


  • Motivation for study

Presentation Outlines

First Presentation: Paleoclimatology


  • Global surface temperatures have been instrumentally measured since about 1880, and satellites and weather balloons have monitored temperatures of the troposphere and stratosphere since 1979. Both sets of measurements show a general warming trend.
  • We need to understand the natural temperature variation of the Earth in order to figure out if current temperature changes are natural or unnatural. To do this, we must reconstruct the history of Earth's climate through the experimental techniques of paleoclimatology.

Discuss Experimental Techniques

  • Historical Data
  • Corals
  • Tree Rings
  • Ice Cores


~Peter Saeta 2010 February 21 at 11:46 AM PST This looks like plenty, Jenna. I'm sure people will be interested to understand just how this evidence is used to infer temperature, and with what reliability.

Second Presentation: Climate Models, Dissidents, and the Fate of the World

Answer Q's from last time

Climate Models

  • Forcings and feedbacks (IPCC TAR Ch 7)
  • Types of Models (Wikipedia as a starting place)
  • Accuracy/Reliability (IPCC TAR Ch 8)

General Predictions of Best Models (IPCC TAR Ch 9)

Consensus and Dissidents

Early Brainstorming


  • What experimental techniques are used to study the past climate of Earth (before the invention of the thermometer)?
  • How do we determine the nature of feedback processes?


  • How do the current climate models work?
  • What assumptions/simplifications are made?
  • What are the major differences between models?
  • What do the models predict about the future climate?


  • Do any scientists disagree that global warming is primarily caused by human activity?
    • What is their evidence?