Friday, November 18, 2005

Sir Humphrey's Spinning Unspin

Sir Humphrey's is taking a while to get up and running and it seems that are..... anti-global warming activists. Great, just what the world needs, more uninformed debate about technical issues that take about a decade to get to grips with probably followed up with some statement similar to '...i'm no scientist sucking on the govt teat but i think its getting colder where i live so this greenhouse gas stuff is bunkum...'.
Go join forces with that powerhouse of NZ intellectual debate 'Investigate' magazine, you've set yourself up well for an invited blog post.
What does the paper say?

Journal of Atmospheric and Solar-Terrestrial Physics
Volume 67, Issue 16 , November 2005, Pages 1573-1579

Regional sun–climate interaction

A. KilcikCorresponding Author Contact Information, E-mail The Corresponding Author

Department of Physics, Faculty of Science, Akdeniz University, 07058 Antalya, Turkey

Abstract

It is a clear fact that the Earth's climate has been changing since the pre-industrial era, especially during the last three decades. This change is generally attributed to three main factors: greenhouse gases (GHGs), aerosols, and solar activity changes. However, these factors are not all-independent. Furthermore, contributions of the above-mentioned factors are still disputed.

We sought whether a parallelism between the solar activity variations and the changes in the Earth's climate can be established. For this, we compared the solar irradiance model data reconstructed by J. Lean to surface air temperature variations of two countries: USA and Japan. Comparison was carried out in two categories: correlations and periodicities. We utilized data from a total of 60 stations, 18 in USA and 42 in Japan. USA data range from 1900 to 1995, while Japan data range from 1900 to 1990.

Our analyses yielded a 42 per cent correlation for USA and a 79 per cent for Japan between the temperature and solar irradiance. Moreover, both data sets showed similar periodicities. Hence, our results indicate marked influence of solar activity variations on the Earth's climate.

Means that 6% of the variation in temp in the USA (parameter weighting = sqrt(correlation co-efficient) is due to solar radiation and 9% in Japan. Sounds reasonable, you'd expect sunshine levels to have a heating effect and on the order of 5-10% doesn't sound too surprising.
And from the conclusion (my emphasis):


We know that a great deal of effort has been put to determine the effects of solar variability on the Earth's climate, and that, to explain the effects of all relevant factors in climate change, one needs to consider a model on a scale of decades to centuries. For the time being, proposed models are not yet of sufficient accuracy to permit any verification (Rozelot, 2001). This study is more a “heuristic” guide to the determination of the principal factors controlling our climate system. We obtained different correlation coefficients between temperatures and solar irradiance depending on the region considered, although we obtained almost identical periodicities for all data sets. Despite the fact that we only used the three-step running average smoothing technique, we obtained a fairly high correlation. On the other hand, our results suggest that atmospheric aerosols have more dominant effect on the Earth's climate than GHGs. Moreover, the existence of similar periodicities for all data sets point out that periodicities in the solar activity manifest themselves in periodic variations on the Earth's surface temperature with almost identical periods. However, prominence of this influence is suppressed by increasing concentration of GHGs in the atmosphere.
It's hard to tell (unless you are an actual atmospheric scientist which i'm not) whether this is earth shattering stuff or a PhD student writing his first paper (or more likely something in between). I'm sure those chaps over at IPCC have heard of solar cycles so i don't see how this could be surprising. End result? just another paper adding to the mix that may support GHG naysayers - i don't trust my own ability to judge the raw literature, why the hell would i assume Sir Humphrey's can?
Sounds like a selection bias at work here. If you don't want to believe in GHG since you have a position of priveledge that likes emmiting them, you will find and support any evidence in your favour. As to the conspiricy of 'Big Science' (a great little Orwellian tactic that tries to paint science with the same brush as Big Oil, Big Pharma and Big Tobacco), the only big science that i see is the lobby groups paid for by Big Oil to pour Doubt, Uncertainty and Fear into the argument. Genuine debate is welcome in research (if you've ever seen an anonymous peer review, you will know that punches aren't pulled) but as with most things, the chances of the minority being right is very small - you may be an undiscovered Einstein, but i'm willing to take the bet that you are just plain wrong.
Let me say this clearly - Global Warming may be wrong, i'm hoping it is, but i trust the methodology that reached this conclusion a 1000x more than i trust people that say there is no problem since by and large, they will be inconvenianced by any change in the status-quo.



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