As a lay person I admire your efforts to Figure out and correct Mr. Hansen’s data, analyses, syntheses, and conclusions. However, I believe it to be empirically and logically impossible to adjust “urban” surface instrument data points or time series to remove a heat island effect – by using rural data points or times series. I see no conceptual basis for doing so.

I agree with Bruce Hall. The best scientific (and political) approach is to select “rural station” (aka from environments not much affected by man) data from rural stations so numerous and geographically dispersed and representative, that it would be difficult to maintain that the temps measured do not represent a reasonable picture of temperature change caused by changes to the greenhouse while excuding changes to the ground in “urban” areas.

If this is purely presentational then why do it? It causes confusion as the distant past can get revised each year by approximately the difference between the last two years’ urban-rural temperature differences. If there is a genuine right hand slope then this across the board change in the adjustment is biased (i.e. has a non-zero expectation).

If it is not purely presentational and there is some theoretical justification then it may be the wrong methodology. Recalculating the mean square error using the shifted trend lines will produce a higher figure than could be achieved by fixing the final point to zero before doing the minimisation.

On top of these issues, rounding the adjustments to integers for individual years will probably introduce unnecessary rounding artifacts.

Here at Climate Audit a wide range of data and theories are investigated and audited that have influence on climate policy.

But, the basic cornerstone of AGW theory, thesis that rise in CO2 concentrations is man-made is not studied much in depth. I have in mind peer reviewed works of Zbignjev Jaworowski or Tom Segalstad (see http://www.co2web.info/, or in recent times some very interesting blog posts by Roy Spencer (see here and here) that all assert that much larger portion of CO2 rise is due to the natural factors that IPCC admits, and that temperature reconstructions from ice cores are unreliable (and thus iconic statement of 280 ppm v of preindustrial CO2). As I laymen-economist I am not familiar with all scientific details of the debate, but as a taxpayer interested in what theories and data supports expansive cap-and-trade programs of energy rationing, I would like to see analysis of that problem from some highly competent climate auditors. In one previous occasion, you Steve defended your decision not to touch in this sensitive issue by arguing that your time is scarce. But, you can put in charge some other competent climate auditor to write a post and moderate discussion.

Additionally, you probably would agree that issue whether rise in CO2 content of atmosphere is entirely man-made or not is for overall evaluation of official IPCC AGW theories (your main proclaimed task) much more important than whether Jim Hansen inflated temperature rise by one additional tenth of degree C of dubious adjustment (which is not by itself unimportant issue or one not deserving to be audited). But, if serious work exist that challenge most basic tenet of AGW, isn’t your duty as Climate Audit, best science blog in the world, to address this issue, to give every pro et con, and to conclude whatever your conclusion will be, eg. that Segalstad, Jaworowski or Spencer are fools. But, let’s first investigate their arguments and prove they are wrong, and why they are wrong (or right).

The odd thing is that they spend some much clusmy effort on adjusting the US which is a miniscual portion of the entire global.

odd

Wouldn’t the large N be necessary to be able to claim significant temperature increases for the past century with the confidence expressed by IPCC and others?

‘Julian Flood’

Not me, vicar. I’m the ‘global warming is caused by oil/surfactant altering CCN numbers and thus modulating low level albedo’ fruitcake — I have no knowledge of USian politics.

JF

That shows how nonsensical the methodology is. Even a congressman/congresswoman with no scientific background can grasp how ridiculous that is.

Methinks you have far too much faith in our elected representatives.