Previous Chapter: 5 - The CARDINAL Model – Summarised Construction and Outcomes

Chapter 6 - Validity of the Models and their Projections


How well do the Models fit Observations?

The central purpose of this book is to assess how well different greenhouse-effect models fit the observational record from 1985 to 2022. This is the definitive test of scientific validity. A model may be mathematically elegant or widely accepted, but if it cannot reproduce known behaviour, it cannot be trusted to predict future behaviour.

The IPCC Model performs poorly when compared to observations. Because it is built on the assertion that anthropogenic emissions cause warming, its structure forces it to show rising greenhouse effect values regardless of short-term or medium-term fluctuations. As a result, it fails to capture periods of cooling, such as the decline in global temperatures from 1998 to 2008. The model diverges from real-world data in magnitude, trend, and shape, which indicates that its core assumptions do not describe the climate system accurately.

The TRANS Model performs better, because it allows for natural variability and partitions contributions from greenhouse-gas changes since 1750. It captures some of the features of the observational record but still cannot match the total greenhouse effect across all 459 months. Its structure is an improvement over assertion-based models but does not fully reflect the complexity of the climate system.

The Cardinal Model stands out as the only model that matches the observed record closely and consistently. By using empirical parameters derived through variance minimisation, it reproduces both the overall trend and the fine structure of monthly variations. Across the entire series from 1985 to 2022, the Cardinal Model aligns so closely with observation that the two lines are visually indistinguishable. This exact match demonstrates that natural variability plays a major role and that greenhouse-gas increases contribute only a modest amount to the total effect.


What can be said about historic data to 2024/25?

The extended observational record through 2024 and into 2025 shows no evidence of accelerating warming or runaway greenhouse behaviour. Temperature changes continue to fluctuate within a natural range, influenced by oceanic oscillations, volcanic activity, and long-term climate variability. These fluctuations are inconsistent with the continuous, monotonic warming predicted by high-sensitivity climate models.

The historical data confirm three key findings:

  1. Warming since 1750 is real, but modest, and within the bounds of natural climate variability.
  2. The period 1985 to 2022 provides the most reliable observational window, and models must match this data to be considered scientifically credible.
  3. There is no structural change in the climate system that supports the assumption of rapidly increasing climate sensitivity.

The IPCC Model overestimates warming because of its reliance on strong, unvalidated water-vapour feedbacks. The TRANS Model captures some variability but still overstates the anthropogenic component. The Cardinal Model, however, fits the extended record without modification, reinforcing its position as the most realistic descriptive model of the greenhouse effect.


What can be said about projections from 2024/25?

Because the IPCC Model fails to match the past, its projections of future warming are unreliable. A model that cannot reproduce known history cannot be expected to predict future conditions. Projections of several degrees of warming by mid- or late-century depend on sensitivity assumptions that are unsupported by observational data.

The TRANS Model offers more moderate projections but still overestimates warming by assuming that greenhouse gases play a dominant role. Its forward behaviour remains speculative because its fit to the observations is incomplete.

The Cardinal Model provides the most reasonable projections. By grounding its parameters in real data and not relying on speculative amplification factors, it predicts modest warming over the coming decades. Natural variability remains the largest component of future behaviour, with greenhouse-gas increases adding only small adjustments. Importantly, the Cardinal Model does not predict catastrophic warming or climate emergency scenarios.

Overall, the evidence indicates that climate projections must be based on models that can be validated against real-world data, not on models that embed their conclusions within their assumptions. Chapter 6 therefore concludes Section One by showing that only the Cardinal Model meets the criteria for scientific credibility, and that long-term climate fear narratives are unsupported by validated models.


Next Chapter: (End of Section One)