Climate: Uncertainty Means That Things Can Be Worse Than Our Best Guess: Part I

A detailed look at uncertainty.

William Briggs writes:

The title sentence was spoken by professor Stephan Lewandowsky from the School of Psychology, University of Western Australia. The psychologist Lewandowsky is concerned that many are not as concerned about climate change as he is.

Lewandowsky is not fretting about the psychological states of warmer citizens. No, sir. He is instead deeply interested in such things as climate feedback sensitivity, heat transfer equations, cloud opacity, and so forth; such states of nature we may describe, in deference to the good prof’s training, as schizophrenic greenhouse gases…

3 thoughts on “Climate: Uncertainty Means That Things Can Be Worse Than Our Best Guess: Part I”

  1. Apparently psychology students are still being taught that mathematics is a world of Cartesian Determinism, and have not yet heard of Chaos Theory or feedback in dynamic non-linear systems.
    Perhaps he would understand that the behaviour of the climate is bipolar.

  2. I have always looked at the issues as a joint probablity exercise for a frame of reference. If this, then this, then this. And it seems there are a lot of thises to get from CO2 forcing all by itself in a lab to CO2 forcing catastrophic climate change that adjusting man-made CO2 can change in a statistically significant way. It only takes 7 conditions of which you are 90% sure to end up with only a probability of 47.8%. Perhaps some statistician could better identify and describe the probability dynamics, but 90% certainty of the IPCC’s AGW in the last 50 years of a half degree C (2/3 of 0.8 since 1980) now seems 100% lilkey to be overstated by at least 50%. With 33% probability that we’ll warm a little bit more because of it, 33% that we won’t, and 33% that we’ll cool despite an increase of CO2. Assuming CO2 rises significantly and nothing else intervenes and “catastrophe” ensues. It doesn’t take anything like 7 steps to get to below 50% and there are a lot more steps than 7. BTW, what is the probability of runaway global warming given that it’s never happened even when there were higher levels of CO2?

    The expected value of the possible NET catatastrophe [well, it’s as possible as zombies though less likey than volcanic winter and CO2 warming is sure to have some positive benefits like Icelandic vineyards] is not – by a long shot – equal to the 47% of world GDP to get a theoretcially measurable effect. [E.G., Monckton’s use of Australian carbon tax scheme to theoretically affect CO2 emissions of Australia to project cost of addressing AGW.]

    I would also say that Briggs, as a statistician, has more expert authority to speak on the hockey stick analysis than Dr. Mike. It’s all statiistical fitting and reading selective tree ring leaves and nothing to do with science.

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