Daily Archives: August 25, 2011

IPCC Climate models lack “correspondence”

I’ve discussed elsewhere the importance of both “correspondence” and “coherence” when attempting to use computer models to represent a physical system and/or interpret model simulations. “Correspondence” deals with the question: “How well does the model code represent the physical phenomenon being simulated?”

If “correspondence” cannot be satisfactorily demonstrated, then any modeler must be prepared for other scientists and policy makers to not believe their model projections, even when those projections only represent hypothetical scenarios. This applies to models of all sizes and sophistication (whether laptop spreadsheet or supercomputer).

The ink blot description of climate science as practiced by the UN International Panel on Climate Change (IPCC) described by Dr. Pielke, Jr. (click here) is very appropriate….but it misses the mark in one very important respect. The post modern view of science says their is no objective reality, and what is real is what is only constructed in the mind. If we believe it, it must be real, even if it is only a model. (The post modern university will not have much to say about which ink blot interpretation is actually “true”……)

However, an objective reality apart from our minds does indeed exist….just ask the tornado victims….and models must have a high “correspondence” to what is objectively true or the models at best are not very useful (or worthless, as some would argue) and results are misleading. Demonstrating “correspondence” is necessary to establish confidence that a model is a reasonable representation, within its limits and uncertainties. This view says “If it is true, then we should believe it.” This is very contrary to the post modern mindset.

Perhaps the most important way to establish “correspondence” is to validate and calibrate models with experimental data or real-world measurements and observations. Model-generated numbers are not “data” in the traditional sense. “Data” must be generated by application of the scientific method or in the case of climate, actual weather and climatic observations over space and time.

The error of post modern thinking (e.g., relativism) can also manifest itself in utility strategic planning, where scenario building is often used. Remember, even in strategic planning: garbage in, garbage out = time and money wasted.

Kirby et al 2011: Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation

Kirkby, J. et al. 2011. Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation. Nature, 476: 429–433 (25 August 2011) doi:10.1038/nature10343

Jasper Kirkby of CERN and his 62 co-authors, from 17 institutes in Europe and the USA, announce big effects of pions from an accelerator, which simulate the cosmic rays and ionize the air in the experimental chamber. Click here for the letter in Nature. These pions were observed to strongly promote the formation of clusters of sulphuric acid and water molecules. These aerosols are of the kind that may grow into cloud condensation nuclei on which cloud droplets form.

In short: cosmic rays influence cloud seeds….influencing climate. This has BIG implications for climate science.

For further discussion click here and click here.