Those who have examined the Wallace, Christy, and d’Aleo (WCD) 2016 and 2017 reports discussed in recent months on this blog may be understandably confused as to how they relate to the numerous climate models used by the UN IPCC and the USEPA over many years in support of their climate alarmism. The methodologies used are entirely different and the conclusions are largely if not totally opposite. The purpose of this post is to try to explain why and reach a judgment as to which one is scientifically valid. Only one is likely to be given the opposite conclusions.

The UN selected two parent organizations for their Intergovernmental Panel on Climate Change (IPCC) effort to show how modern civilization was bound to fail because of catastrophic global temperature increases. (Yes, the UN IPCC effort has never been a neutral one.) These parent organizations were the UN World Meteorological Organization (UNWMO), made up of the national meteorological organizations (such as NOAA in the US) and the UN Environment Programme (UNEP).

The UNWMO and its member national weather services in each country have had extensive experience with General Circulation Models (GCMs) because they have long used them for weather forecasting, which is what they do for a living. So this may have led to a decision to adapt them to the new purpose, climate forecasting, in response to the UN’s interest in this new problem in the late 20th Century. They have continued using this application over several decades until the present day. The GCM models may be the best approach to short-term weather forecasting but are well known to fail for longer-term (even as little as two weeks) weather forecasting.

They are particularly bad for climate forecasting, because it involves long periods of the operation of a coupled, non-linear chaotic system. Mike Jonas has argued that “It is clear that no matter how much more knowledge and effort is put into the climate models, and no matter how many more billions of dollars are poured into them, they can never be used for climate prediction while they retain the same basic structure and methodology.”

In my view the climate GCMs should never have been assumed to be sufficiently reliable for determining climate policy. But that is exactly the opposite of what has been done by the UN, climate alarmist groups, and even the Obama Administration. Even the IPCC itself admits (2007, WG1) that: “We should recognize that we are dealing with a coupled nonlinear chaotic system, and therefore that the long-term prediction of future climate states is not possible.”

So the UN IPCC attempted to undertake the gargantuan task of modelling the climate as a whole by aggregating data from a large number of grid cells covering the planet as part of their GCM methodology. Any new variable used requires additional data for each grid cell and an understanding of exactly how the new variable affects other variables. The results are extremely sensitive to the assumed initial conditions. In doing this Jonas argues that they left out some really important explanatory variables that explain global temperatures according to the results of the WCD reports.

The IPCC climate GCM effort quickly reached the limits of computer power, available budgets, and knowledge of how many important climate variables work. Because of this, lack of interest, or lack of knowledge, Mike Jonas believes major variables were left out of the GCMs, including oceanic oscillations, volcanic eruptions, and changes in the sun. Even a quick glance at global temperature charts over recent decades shows the great importance of oceanic oscillations, particularly the El Nino Southern Oscillations (ENSO) such as El Nino and La Nina. Yet the GCMs apparently left them out, possibly because they had little idea how they functioned or wanted the world to concentrate on their CO 2 -centric views.

For reasons explained by Jonas, the UN GCM effort was impossible from the start, has been much more complicated than necessary to answer the key questions, and is highly questionable as to their conclusions because of the IPCC’s decision to use GCM climate models. This will continue to be the case as long as these models are the principal tool used. The IPCC has been using a poor tool and not admitting that the tool has little if anything to contribute to solving the alleged problem.

The WCD Econometric Approach

Jonas recommends a top-down rather than the IPCC’s bottom-up GCM approach. The WCD econometric approach would appear to fit that description. Rather than trying to understand all aspects of climate in each grid cell in the world (but leaving out major explanatory variables), they picked out the variables that seemed most likely to affect the one they cared about (tropical and global temperatures), and used available data sets to determine the impact/contribution of each explanatory variable to the variable they cared about. They did not need to understand the physical interactions between every variable in each grid cell since all they wanted to know is how much of an effect each relevant explanatory variable had on tropical and global temperatures. They also used a completely different methodology and discipline, called econometrics, a subdiscipline of economics, not meteorology.

The computer effort required by the WCD approach is vastly smaller and the importance of each explanatory variable is determined by data, not the guesswork of fallible and all too often biased humans in the IPCC GCM efforts. Major explanatory variables are included rather than being left out. This approach does not show exactly how each variable operates, only how much of an effect it has on the critical dependent variable (global temperature). One potential complication is that a simultaneous parameter estimation process must be used, not just a direct least squares, on a single temperature equation. This process is somewhat more difficult to carry out, but in the end was not needed in this particular case because CO 2 was shown to have no significant effect on temperature.

In summary, a much better and far simpler approach (if anything was needed at all) by the IPCC would have been that instead of turning to vastly complicated and ill-suited meteorological models and ignoring many of the obvious variables that might actually determine global temperatures (such as solar and volcanic activity, and ENSO oceanic oscillations), would have been to use the available data to determine the extent to which each of these and other variables affect global temperatures using statistical econometric techniques.

The IPCC models do the opposite by using current knowledge to try to determine the relationships between various somewhat known factors influencing climate and ignoring many of the variables of some importance, and then fiddling with the remaining unknowns to “tune” the models to fit historical observations but not necessarily the physics. This is nothing more than guesswork (and probably biased guesswork in this case) and is so unreliable as to be worthless despite the tens of billions of dollars spent on this approach. It has brought unexpected riches to the former meteorological modelers (now called climatologists) but has cost taxpayers dearly in terms of paying for the useless research and the faulty climate policies that are “justified” on the basis of useless and biased GCMs.

So a much more useful approach would have been (if anything, since climate alarmism is basically a non-problem) to turn to a completely different discipline: econometrics, as used in the WCD reports. Unfortunately this may have been precluded by the UN’s original choice of the WMO to pair with the UNEP.

An interesting question is whether the IPCC’s choice of using GCMs may also have been influenced by a guess that this would greatly complicate the task of critics by requiring the use of advanced expertise in many areas to understand the results. It may also have been the view of some climate researchers that this was a golden opportunity to get their climate GCM “play things” funded by taxpayers. Or maybe it was just ignorance on the part of the UNWMO and the IPCC as a whole concerning the usefulness of climate GCMs.

What the WCD Reports and IPCC Models Have Concluded

And what do the WCD reports done to date (on a pro bono basis) conclude: the IPCC GCM conclusions are wrong on the major issue of what effect CO 2 has on temperatures. The IPCC models have been used to argue that CO 2 is a virtual “control knob” for global temperatures. The WCD reports conclude that changes in CO 2 have no statistically significant effects on temperatures. Global warming over the range of data used can be explained by natural factors when they are included as explanatory variables.

So which to believe? The IPCC modelers undertook a hopeless research effort and appear to have left out what turned out to be critical variables in their reports. WCD undertook a doable effort focused on the much needed answers to a few critical questions. The answer is very clear to me.

My Conclusions

I suggest a complete moratorium on climate alarmist-inspired spending until more detailed comparisons can be made and examined by all concerned. I personally believe we know enough to decide now to abandon the use of all GCM climate modeling and all efforts to reduce CO 2 emissions.

Tens of trillions of dollars have been wasted in part because of the initial UN decision as to which disciplines should be involved in the research and the decision that the IPCC models were a sufficiently reliable basis on which to base climate policy. And all this should have been known before any work was ever started.

And as long as these misguided UN efforts are continued the world will probably continue to waste about $1.5 trillion per year for almost no benefits on the greatest scam in world history. The US should no longer participate in or fund the hopeless IPCC GCM effort.