Antarctic Ice Cores: The Sample Rate Problem

Antarctic Ice Cores: The Sample Rate Problem. Geologist David Middleton returns to tell us that those Antarctic ice cores that seem to support the climatology conspiracy consensus can’t be trusted. After-all, the ice doesn’t permanently capture the CO2 level at the exact instant it begins to form. Also, maybe CO2 got sucked out of the old ice. And everyone knows that only second-by-second CO2 samples can be trusted.

Actually, David is suggesting that the ice CO2 levels blend a bit. He wants us to think that maybe there have been large fluctuations in atmospheric CO2 that have been blurred together and are no longer seen in the ice samples, maybe the modern CO2 trend just happens to be an ordinary large natural swing in CO2, and that we just happen to be at the peak of one of those “swings”.

Although, if the ice cores chanced to suit denialist wishes I’m sure they’d be just fine. In this case the erratic plant leaf stomata CO2 proxy values (sotto voce: does David know that they are a computer model?) are praised because they show large fluctuations that can be used to “prove” that there has been wide variation in the modern era and hence today’s CO2 levels are perfectly natural.

This puzzling quote comes from one of the apparently supporting papers, CO2 diffusion in polar ice: observations from naturally formed CO2 spikes in the Siple Dome (Antarctica) ice core (italics mine):

“Smoothing of the CO2 record by diffusion is one to two orders of magnitude smaller than the smoothing by diffusion in the firn at the depth of 287m (gas age = 2.74 kyr BP) in the Siple Dome ice, and so does not degrade the record.”

So… scientists know about this crazy diffusion thing and have been able to assess it as being insignificant. So what’s David really trying to do?

Prediction is hard, especially of the future.

Prediction is hard, especially of the future. Willis Eschenbach tries to convince us that “problems” with 20 year-old computer models mean that we can’t trust the new ones.

Did Hansen, et. al.’s 1992 prediction Potential climate impact of Mount Pinatubo eruption really “miss the mark”? After all, they did predict a “3 sigma” event and the result was only a “2.1 sigma” event… It seems that they correctly predicted the temperature drop duration but over-estimated the scale. Not too shabby for 20 year-old model run with 20 year-old computer horsepower.

Of course Willis doesn’t give any hard numbers for his suggestion that their prediction “failed”. Couldn’t find an Excel formula for that, Willis?

And how did the much more relevant climate model prediction, 20 more years of increasing global temperatures, work out? Oh yeah, that’s what we’ve had. Willis’ insights are no better that Yogi Berra’s.

This is all just an attempt to prop up denialist obstructionism by suggesting that since we can’t predict the future perfectly we should never take any kind of preventative action at all.

CO2: Ice Cores vs. Plant Stomata

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?

The Madden – Julian Oscillation

The Madden – Julian Oscillation. Anthony Watts discovers that our atmosphere sloshes! There are currents everywhere! This means that there is no Global Warming, it’s all natural oscillations!

Anthony pastes in a 1998 atmospheric science web textbook chapter to show his new knowledge, in particular about the short-period (40-50 days) tropical Madden – Julian Oscillation. But he must have choked on this sentence, unless he never read it:

Notwithstanding its complexity and dependence on convection, the essence of the MJO (its periodicity, structure and zonal asymmetry) can be simulated in a GCM.

That sounds like a vindication of Global Circulation Models… They’re evil, corrupt, and always wrong!

Testing … testing … is this model powered up?

Testing … testing … is this model powered up?” Willis Eschenbach guest posts on Anthony Watts’ website and mentions about Judith Curry’s “excellent blog”, where she has apparently been talking in her usual vague way about a subject that she seems to have only a superficial understanding of. In this case about “verifying and validating” climate models.

After drowning us in a deluge of Excel charts derived from a variety of old (6+ years) climate models and using a conveniently short 20-year span, Willis tells us that generalized climate models don’t mirror the specific fluctuations of real temperature trends well enough. This, somehow, is a surprise to Willis. Apparently all the climate models must be discarded now.

Newsflash: “general” is not “specific”. The impact of one-time events will never be predicted. Regardless, I guess we can’t trust any of them sneaky climate computer models, can we Anthony?

Ocean color affects tropical cyclone formation

Ocean color affects tropical cyclone formation. Another filler post from Anthony Watts, this time a press release from all the way back on 13 August about a NOAA paper titled “How ocean color can steer Pacific tropical cyclones“. I suppose this is fodder for the “them climate scientists don’t know a dang thing” file.

The climate modeling premise? “Greener” water absorbs more heat and heats the air above more, with the effect of pushing cyclones towards higher latitudes and increasing their energy. An interesting finding.

Antarctic sea ice increase not linked to ozone hole

Antarctic sea ice increase not linked to ozone hole. Anthony Watts has discovered a two paragraph news report about a paper in Geophysical Research Letters titled “Has the ozone hole contributed to increased Antarctic sea ice extent?” Here’s the paper’s heart:

Contrary to expectations, our model simulates a year-round decrease in Antarctic sea ice due to stratospheric ozone depletion. The largest percentage sea ice decrease in our model occurs in the austral summer near the coast of Antarctica, due to a mechanism involving offshore Ekman sea ice transport.

Ooh, they’re talking about computer models! Anthony hates computer models, he’s totally going to tear them a new one! Wait, why is he as quiet as a church-mouse? This particular computer modeling happens to be useful to denialists, so it gets accepted unquestioningly.

The Antarctic ozone hole. From NASA Goddard Space Flight Center.

So which is right, this new climate model or the older ones that linked ozone depletion to increased Antarctic sea ice? Anthony doesn’t seem to care really, he just wants to shout that there is ‘no global warming.’