Monday, August 03, 2009

John Maclean Is Back To Mis-Representing His Own Paper

Will the world get warmer if there is an El Nino? Yes, that's extremely likely. In recent paper that I co-wrote with Professor Bob Carter and Professor Chris de Freitas we showed that the the average global temperature as measured from satellites shifts about 7 months after a corresponding shift in the El Nino-Southern Oscillation (ENSO). The visual correlation is so good (see our figure 7) that its clear that the ENSO is the primary driver. The absence of any residual warming (i.e. warming that the ENSO cannot account for) means that carbon dioxide has negligible, if any, effect.

See here .

In anticipation of certain comments... (a) we use the analysis as a means of exploring a relationship and as a means to an end, which figure 7 amply demonstrates, (b) we do not use temperature data measured at the surface because it has far too many inconsistencies, and (c) we often use the word "trends" in a general sense rather than a statistical sense (where the exact line will be described to an accuracy of several decimal places).

I've written about the paper in question here, and there are plenty of links in that post to other, more systematic debunkings. But what is important is that, after admitting (along with his co-authors) that the paper in question "does not analyse trends" (meaning it has nothing to offer to the AGW debate), McLeans now wants it to be about trends again--though "trends" in some non-statistical sense. But not, I would argue, about "trends" in the general sense (meaning "general tendency or inclination"), because that was precisely the sense of the term at issue when De Freitas and co. previously admitted their work was not about trends. I admit to being somewhat confused by the 2nd paragraph, and suspect it is straight bullshit. I mean, the statistical sense is the general sense, no?

Sigh. Its hard to explain bullshit.



John Cross said...

Wow, talk about confused. His second paragraph talks about everything but the central criticism to his paper which is that it removes the trend - period!

Also I note that Spencer's site is still showing that the current year is at an all time high. That will soon be a month!


John said...

Why can't some one simply address the isues raised in the paper with a brief scientific critique showing where you believe the authors are wrong and what you would see as the correct interpretation of the data.

What McLean says about the correlatiion between SOI and temperature, if the data he uses is correct, appears to be unassailable. There appears to be no question whatsoever, that the trends, statistical or otherwise, he is pointing to, are properly interpreted. In Figure 1, the raw data, shows the long term trend with the line representing the temperature moving consistently up wards while he SOI data moves downwards with closely matching features along the way. There is no fitting or fiddling as far as we are aware, such as was he case with the now infamous Manne Hockey Stick. In most atmospheric, ionospheric or even many laboratory measurements, one would be excited to find such close parallels as demonstrated in all of these graphs. The only reasonable argument is one of causality - does global warming cause changes to ENSO or is ENSO responsible for Global Warming. I believe that the seven months lag would suggest that ENSO drives the warming, just as in geological records, the 800 year lag between carbon dioxide increases and temperature, suggests the temperature is driving carbon dioxide out of the oceans rather than that carbon dixide is causing the warming. This is particularly when one considers that the reversion to an ice age occurs invariably when CO2 concentrations have almost reached their maxima. However, there may counter arguments to my opnion and I would like to hear them.

Why can't we leave the a hominem remarks behind and purge the insults. Simply concentrate on the scientific discussion in hand.

John Nicol

John Cross said...

John: many people have done that exact thing for this paper. The best one line I have read is from Tamino:

The fact is that their methodology, the process of estimating derivatives by taking 1-year differences, transforms any trend into a constant and thereby eliminates its impact on all variation and correlation.

The correct interpretation of the data is that ENSO has a great deal to do with the variability of the data but since their process eliminates the trend it tells us nothing about whether the temperature is rising. This is not new work.

Now, let me ask you. Does the above address your comment?