Previous Chapter: 4 - The TRANS Model – Summarised: Construction and Outcomes
The Cardinal Model is an empirically built descriptive model designed to explain the total greenhouse effect using as few assumptions as possible. Unlike the IPCC Model, which begins with the assertion that anthropogenic emissions cause global warming, and unlike the TRANS Model, which partitions effects between historical and modern greenhouse-gas contributions, the Cardinal Model starts from the observational record itself.
Its structure relies on a small number of parameters derived through variance minimisation. That is, the parameters are chosen such that the resulting model matches the observed greenhouse-effect data from 1985 to 2022 as closely as possible. This gives the Cardinal Model a significant advantage: its parameters are not imposed by theory or political assumptions but are informed directly by the data.
A central premise of the model is that natural climate variability is the dominant driver of the total greenhouse effect. Greenhouse gases do contribute, but the contribution is much smaller than suggested by assertion-driven models. This view is consistent with the historical record, which shows substantial natural climate shifts over millennia and centuries long before industrial emissions.
The Cardinal Model includes separate terms for natural variability, modern increases in greenhouse gases, and smaller corrective components necessary for reproducing the observed monthly greenhouse-effect pattern. The result is a model that is simple, empirical, and capable of matching real-world observations with exceptional precision.
The empirical optimisation used in the Cardinal Model yields a structure that not only matches the overall rise in the greenhouse effect between 1985 and 2022, but also the month-to-month fluctuations and long-term patterns. This is in stark contrast to IPCC-style models, which fail to reproduce even the broad trend without assuming large sensitivity multipliers.
One of the most striking outcomes of the Cardinal Model is that it can reproduce the observed greenhouse effect exactly. When the model values are plotted against the real data across the entire 459-month record, the two lines are visually indistinguishable. The correlation is extremely high, and the variance between model and observation is minimised by construction.
This does not mean the model is merely curve-fitting. The parameters that arise from the optimisation have physical interpretations consistent with the behaviour of greenhouse gases and natural climate oscillations. In particular, the model naturally incorporates the influence of water vapour and temperature-dependent interactions without invoking strong amplification factors or assumptions of runaway feedbacks.
The outcomes of the Cardinal Model challenge the narrative that recent warming must be predominantly human-driven. Instead, the model implies that:
By matching the observational record so well, the Cardinal Model provides a scientifically grounded alternative to assertion-driven approaches. It demonstrates that a model can fit reality without assuming that human emissions dominate the climate system.
Chapter 5 therefore positions the Cardinal Model as the most scientifically credible of the three models examined. It matches observations precisely, relies on transparent empirical methods, and avoids the circular logic embedded in the IPCC’s causation-based structure.
Next Chapter: 6 - Validity of the Models and their Projections