I was alerted to an informative new paper on the issue of what is climate
The paper highlights the nonstationarity of climate as we presented in the papers
Pielke, R.A., 1998: Climate prediction as an initial value problem. Bull. Amer. Meteor. Soc., 79, 2743-2746.
As I wrote in that paper
“weather prediction is a subset of climate prediction and that both are, therefore, initial value problems in the context of nonlinear geophysical flow.’
“…..longer-term feedback and physical processes must be included. This makes climate prediction a much more difficult problem than weather prediction”.