“Is Climate Really Predictable On 10-50 Year Time Scales?”

  • Date: 18/07/10

Bill Cotton , a Professor at the Department of Atmospheric Science at Colorado State University (and a colleague of mine) has given a lecture

Cotton, W.R., 2010: Is Climate Really Predictable on 10-50 Year Time Scales?  International Symposium on Prediction, San Diego, CA, July 2010.

The entire set of slides is worth viewing. Selected conclusions that he reports are

i) It is often claimed that climate is predictable because it is a boundary value problem (that is, only changes in external forcing is needed).
ii) But, we noted that deep ocean variability occurs on time scales of 100’s of years
iii) Thus initialization of deep ocean circulations is needed for forecasts on decadal time scales.
iv) This means that decadal climate prediction is both an initial value problem and boundary value problem


Considering the stochastic external forcing parameters (eg. volcanoes), uncertainties of solar variability forcing, and the tendency for strong model biases on time scales of 2-5 years let alone 10 to 50 years, I see no evidence that climate is predictable on these time-scales nor will it be for decades to come (a forecast!).

Climate Science, Roger Pielke Sr, 14 July 2010

Recent Popular Articles

We use cookies to help give you the best experience on our website. By continuing without changing your cookie settings, we assume you agree to this. Please read our privacy policy to find out more.