Understanding climate models

If you’ve heard about any climate cycle, it’s probably the El Niño Southern Oscillation, or ENSO. 2015/2016 is looking like it might bring a record El Niño, and media coverage is, for climate, pretty remarkable.

The coverage is understandable, as weird things happen during big El Niños. The eastern tropical Pacific Ocean is anomalously warm during boreal winter. Deep convection moves away from the Western Pacific Warm Pool, and other bits of the climate system tend to shift to unusual states.

Sometimes! My house in northern California might flood this winter, but then again it might not.

Even though ENSO is correlated with climate variations all over the place, the explained variance is often small. Pretty much every big El Niño is its own beast, and the field is still working towards a prediction system that has skill at more than seasonal time scales. Decadal- to centennial-scale projections remain uncertain.

Mat Collins, from the University of Exeter, is one of the world’s leading authorities on ENSO. As we discuss in episode 2 of Forecast, while many aspects of ENSO predictability indeed haven’t gotten much better, other aspects are now far better understood. Mat and I also discuss how working with the Intergovernmental Panel on Climate Change is like dealing with a hangover, atmospheric circulation on Mars, uncertainties in climate modeling, and how to talk to a statistician.