“CO2: Ice Cores vs. Plant Stomata“. More Christmas Guest pudding! Geologist David Middleton takes on the “Warmista Junk Science”. I think he was a classmate. [Update: No, thank god] How depressing to see him parroting the decrepit “Hockey Stick” aspersions and casting about for excuses to prefer weaker data that ‘suggests’ results that suit his purpose.

Ironically David reflexively deplores “Mike’s Nature Trick“, which boils down to plotting temperature proxies over just the period for which they can be demonstrated to be reliable, but mimics it in his arguments. He tries to deprecate the widely accepted ice core data by combining sparse, erratic, leaf stomata temperature proxies and the insensitive (10 million year increments!) GEOCARB III geochemical model of Phanerozoic atmospheric CO2. This apparently requires lots of very busy charts to give the impression of analysis, but lets him simultaneously claim that ice cores don’t capture the variability the way the stomata proxies allegedly do and that the ice core CO2 is too low in CO2 when compared to the monotonic GEOCARB III data. Nice “trick”.

After all those charts, what is David’s compelling “analysis”? Wishful eyeballing.

In his conclusions David repeats the debunked denialist claim that the “carbon cycle lags behind the climate cycle and thus does not drive the climate cycle” and that “anthropogenic contribution to the carbon cycle since 1860 is minimal and inconsequential.” Yeah, the carbon cycle lag was true over geological time when organic productivity was linked to natural climate variation. The problem now is that carbon release by man has turned the feedback response into the driver and is proceeding at a rate that is an order of magnitude faster. Claiming that the anthropogenic contribution is minimal is just a baseless assertion. Plugging your ears and singing “lalalalalala” isn’t going to change these things.

This is just another case of a denialist who can’t find a successful argument resorting to fabricating one, and David has embraced as many old denialist themes as he can. Naturally he’s greeted by the usual thoughtful exclamations of his Copernican brilliance in the comments that will one day be embarrassing to read. I suppose that in the land of the blind the one-eyed man is king, but why do so many of Anthony’s readers feel compelled to praise such pedestrian efforts? It seems like a hollow attempt at self-reassurance.

What argument could David have made about ice core data without exposing his bias? That they are not sensitive to short-term CO2 variations. Unfortunately this would lead to a new question: so what?