By Paul Homewood
Roy Spencer has written a long, detailed critique of climate models:
https://www.heritage.org/environment/report/global-warming-observations-vs-climate-models
The full report is worth reading, but his key graph and conclusions are below:
Conclusion
Climate models produce too much warming when compared to observations over the past fifty years or so, which is the period of most rapid warming and increases in carbon dioxide in the atmosphere. The discrepancy ranges from over 40 percent for global surface air temperature, about 50 percent for global lower atmospheric temperatures, and even a factor of two to three for the United States in the summertime. This discrepancy is never mentioned when those same models are used as the basis for policy decisions.
Also not mentioned when discussing climate models is their reliance on the assumption that there are no natural sources of long-term climate change. The models must be “tuned” to produce no climate change, and then a human influence is added in the form of a very small, roughly 1 percent change in the global energy balance. While the resulting model warming is claimed to prove that humans are responsible, clearly this is circular reasoning. It does not necessarily mean that the claim is wrong—only that it is based on faith in assumptions about the natural climate system that cannot be shown to be true from observations.
Finally, possible chaotic internal variations will always lead to uncertainty in both global warming projections and explanation of past changes. Given these uncertainties, policymakers should proceed cautiously and not allow themselves to be influenced by exaggerated claims based on demonstrably faulty climate models.
via NOT A LOT OF PEOPLE KNOW THAT
January 26, 2024 at 09:24AM
Iowa Climate Science Education 