Alex Sen Gupta, a biological scientist, has written an article (reviewed by John Cook) which attempts to defend the validity of climate models which can’t predict the climate.

According to Gupta;

To understand what’s happening, it is critical to realise that the climate changes for a number of reasons in addition to CO₂. These include solar variations, volcanic eruptions and human aerosol emissions.

The influence of all these “climate drivers” are included in modern climate models. On top of this, our climate also changes as a result of natural and largely random fluctuations – like the El Nino Southern Oscillation, ENSO and the Interdecadal Pacific Oscillation, [IPO] – that can redistribute heat to the deep ocean (thereby masking surface warming).

Such fluctuations are unpredictable beyond a few months (or possibly years), being triggered by atmospheric and oceanic weather systems. So while models do generate fluctuations like ENSO and IPO, in…