Solar Cycle 24 peaked? The experimentum crucis begins.

The WSO Polar field strengths – early indicators of solar maximums and minimums – have dived towards zero recently, indicating that its all down from here for solar cycle 24.

Polar field reversals can occur within a year of sunspot maximum, but cycle 24 has been so insipid, it would not be surprising if the maximum sunspot number fails to reach the NOAA predicted peak of 90 spots per month, and get no higher than the current 60 spots per month.

The peak in solar intensity was predicted for early 2013, so this would be early, and may be another indication that we are in for a long period of subdued solar cycles.

A prolonged decline in solar output will provide the first crucial experiment to distinguish the accumulation theory of solar driven temperature change, and the AGW theory of CO2 driven temperature change. The accumulation theory predicts global temperature will decline as solar activity falls below its long-term average of around 50 sunspots per month. The AGW theory predicts that temperature will continue to increase as CO2 increases, with little effect from the solar cycle.

An experimentum crucis is considered necessary for a particular hypothesis or theory to be considered an established part of the body of scientific knowledge. A given theory, such as AGW, while in accordance with known data but has not yet produced a critical experiment is typically considered unworthy of full scientific confidence.

Prior to this moment, BOTH solar intensity was generally above its long term average, AND greenhouse gases were increasing. BOTH of these factors could explain generally rising global temperature in the last 50 years. However, now that one factor, solar intensity, is starting to decline and the other, CO2, continues to increase, their effects are in opposition, and the causative factor will become decisive.

For more information see WUWT’s Solar Reference page.

AGW Doesn't Cointegrate: Beenstock's Challenging Analysis Published

The Beenstock, Reingewertz, and Paldor paper on lack of cointegration of global temperature with CO2 has been accepted! This is a technical paper that we have been following since 2009 when an unpublished manuscript appeared, rebutting the statistical link between global temperature increase and anthropogenic factors like CO2, and so represents another nail in the coffin of CAGW. The editor praised the work as “challenging” and “needed in our field of work.”

Does the increase in CO2 concentration and global temperature over the past century, constitute a “warrant” for the anthropogenic global warming (AGW) theory? Such a relationship is a necessary for global warming, but not sufficient, as as range of other effects may make warming due to AGW trivial or less than catastrophic.

While climate models, or GCMs shows enhancement of the greenhouse effect can cause a temperature increase, the observed upward drift in global temperature could have other causes, such as high sensitivity to persistent warming from enhanced solar insolation (accumulation theory). There is also the urban heat island effect and natural cycles in operation.

In short, the CO2/temperature relationship may be spurious, have an independent cause, or temperature may cause CO2 increase, all of which falsify CAGW here and now.

Cointegration attempts to fit the random changes in drift of two or more series together to provide positive evidence of association where those variables are close to a random walk.
The form of time series process appropriate to this model is referred to as I(n), having the property that n is the number of differencing operations needed before the series has a finite mean (stationary, or does not drift far from the mean). A range of statistical tests, the Dickey-Fuller and Phillips-Perron procedures, identify the I(1) property.

Beenstock find that while temperature and solar irradiance series are I(1), anthropogenic greenhouse gas (GHG) series are I(2), requiring differencing twice to yield a stationary series.

This fact blocks any evidence for AGW from an analysis of the time series. The variable may still somehow be causally connected, but not in an obvious way. Previous studies using simple linear regression to make attribution claims must be discounted.

The authors also show evidence of a cointegrating relationship between the temperature (corrected for solar irradiance) and changes in the anthropogenic variables. This highlights what I have been saying in the accumulation that the dynamics relationships between these variables must be give due attention, lest spurious results are obtained.

While this paper does not debunk AGW, it does debunk naïve linear regression methods, and demonstrate the power of applying rigorous statistical methodologies to climate science.

Still no weakening of the Walker Circulation

Once upon a time, a weakening of the East-West Pacific overturning circulation – called the Walker circulation – was regarded in climate science as a robust response to anthropogenic global warming. This belief was based on studies in 2006 and 2007 using climate models.

Together with a number of El Nino events (that are associated with a weakening of the Walker circulation) the alarm was raised in a string of papers (3-6) that global warming was now impacting the Pacific Ocean and that the Walker circulation would further weaken in the 21st century, causing more El Ninos and consequently more severe droughts in Australia.

These types of alarms in the context of a severe Australian drought gave rise to an hysterical reaction of building water desalination plants in the major capital cities in Australia, all but one now moth-balled, and costing consumers upwards of $290 per year in additional water costs.

In 2009 I did a study with Anthony Cox to see if there was any significant evidence of a weakening of the Walker circulation when autocorrelation was taken into account. We found no empirical basis for the claim that observed changes differed from natural variation, and so could not be attributed to Anthropogenic Global Warming.

Since 2009, a number of articles show that, contrary to the predictions of climate models, the Walker has been strengthening (7-12). A recent article gives models a fail: “Observational evidences of Walker circulation change over the last 30 years contrasting with GCM results” here.

The paper by Sohn argues that inceases in the frequency of El Nino cause the apparent weakening of the Walker Circulation, not the other way around, and it is well known that climate models unsuccessfully reproduce such trends.

The problems with models may rest in their treatment of mass flows. In “Indian Ocean warming modulates Pacific climate change” here, they find that

“Extratropical ocean processes and the Indonesia Throughflow could play an important role in redistributing the tropical Indo-Pacific interbasin upper-ocean heat content under global warming.”

Finally from an abstract in 2012 “Reconciling disparate twentieth-century Indo-Pacific ocean temperature trends in the instrumental record” here:

“Additionally, none of the disparate estimates of post-1900 total eastern equatorial Pacific sea surface temperature trends are larger than can be generated by statistically stationary, stochastically forced empirical models that reproduce ENSO evolution in each reconstruction.”

Roughly translated this means there is no evidence of any change to the Walker ciriculation beyond natural variation – weakening or otherwise.

Nice to be proven right again. The “weakening of the Walker Circulation” is another scary bedtime story for global warming alarmists, dismissed by a cursory look at the evidence.


1. Held, I. M. and B. J. Soden, 2006: Robust responses of the hydrological cycle to global warming. J. Climate, 19, 5686–5699.

2. Vecchi, G. A. and B. J. Soden, 2007: Global warming and the weakening of the tropical circulation. J. Climate, 20, 4316–4340.

3. Scott B. Power and Ian N. Smith. Weakening of the walker circulation and apparent dominance of el ni˜no both reach record levels, but has enso really changed? Geophys. Res. Lett., 34, 09 2007.

4. Power SB, Kociuba G (2011) What caused the observed twentieth-century weakeningof the Walker circulation? J Clim 24:6501–56514.

5. Yeh SW, et al. (2009) El Niño in a changing climate. Nature 461(7263):511–514.

6. Collins M, et al. (2010) The impact of global warming on the tropical Pacific Ocean and El Niño. Nat Geosci 3:391–397.

7. Li G, Ren B (2012) Evidence for strengthening of the tropical Pacific Ocean surfacewind speed during 1979-2001. Theor Appl Climatol 107:59–72.

8. Feng M, et al. (2011) The reversal of the multidecadal trends of the equatorial Pacific easterly winds, and the Indonesian Throughflow and Leeuwin Current transports. Geophys Res Lett 38:L11604.

9. Feng M, McPhaden MJ, Lee T (2010) Decadal variability of the Pacific subtropical cells and their influence on the southeast Indian Ocean. Geophys Res Lett 37:L09606.

10. Qiu B, Chen S (2012) Multidecadal sea level and gyre circulation variability in the northwestern tropical Pacific Ocean. J Phys Oceanogr 42:193–206.

11. Merrifield MA (2011) A shift in western tropical Pacific sea-level trends during the 1990s. J Clim 24:4126–4138.

12. Merrifield MA, Maltrud ME (2011) Regional sea level trends due to a Pacific trade wind intensification. Geophys Res Lett 38:L21605.

13. “Observational evidences of Walker circulation change over the last 30 years contrasting with GCM results BJ Sohn, SW Yeh, J Schmetz, HJ Song – Climate Dynamics, 2012 – Springer

14. Indian Ocean warming modulates Pacific climate change Jing-Jia Luoa,b,c,1, Wataru Sasakia, and Yukio Masumotoa

15. “Reconciling disparate twentieth-century Indo-Pacific ocean temperature trends in the instrumental record”. Solomon, A. & Newman, M. Nature Clim. Change 2, 691–699 (2012).”