Read on the checkout line

The latest ignorance spreading through the denialsphere is a provocation published in Pravda by a 9-11 truther (he believes that George did it) with the handle Fegel. This is pretty much standard stuff, Al Gore is FAT* and introduced the now broken hockey stick curve**, CO2 lags warming coming out of an ice age***, etc. As Tim Lambert puts it, remember when right wingers didn't trust Pravda? Pravda appears to have made the jump from Communist Party rag to supermarket checkout line rag without stopping for a rest in the middle. The wonders of the market.


The bottom line in this provocation though is Fegel's propagation of ignorance

The main flaw in the AGW theory is that its proponents focus on evidence from only the past one thousand years at most, while ignoring the evidence from the past million years -- evidence which is essential for a true understanding of climatology. The data from paleoclimatology provides us with an alternative and more credible explanation for the recent global temperature spike, based on the natural cycle of Ice Age maximums and interglacials.

There is a chapter in every IPCC report on paleoclimate, which considers what we know about ice ages in detail. The AR4 chapter concludes (very long download, don't do this on your dial up line):

It is virtually certain that global temperatures during coming centuries will not be signifi cantly influenced by a natural orbitally induced cooling. It is very unlikely that the Earth would naturally enter another ice age for at least 30 kyr.

VIRTUALLY CERTAIN is reserved for such things as the sun will rise in the morning. Science bunnies are very cautious. Besides labeling Fegel for wingnut of the week, we need to dig a bit deeper into this. It has been covered a few places, in a somewhat indirect way, which assumes that the reader has some background. Two are a delicious comment in Deltoid by William Hyde, which ends with

So here we see a denialist using a rejected idea of the early 1970s, which other people in his camp use as an example of bad climate science, as good science which "refutes" AGW.

As it turns out this interglacial looks more like the anomalous stage eleven interglacial, which was of approximately double normal length. By one calculation the "on ramp" for the next ice age occurred 800 years ago, and we missed it. The next one isn't for eleven thousand years.

Come to think of it, that was also discussed in Imbrie and Imbrie. Guess he didn't get to the last chapter.

and Eli will find the other one soon (same point tho).

To really understand why this is such a sure thing (bet the bunnies on it if you can find a long lived sucker) the dedicated reader should go read Imbrie and Imbrie, maybe the last chaper, the AR4, TAR, etc. However, the classic Rabett take is that small orbital changes decrease the amount of sunlight striking the Earth and lead to summers in which ice persists over large areas of the Northern Hemisphere. Ice sheets can therefore grow over time driven by positive feedbacks including changes in the albedo. Taking all this into account the AR4 authors conclude.

6.4.1.8 When Will the Current Interglacial End?

There is no evidence of mechanisms that could mitigate the current global warming by a natural cooling trend. Only a strong reduction in summer insolation at high northern latitudes, along with associated feedbacks, can end the current interglacial.

Given that current low orbital eccentricity will persist over the next tens of thousand years, the effects of precession are minimised, and extremely cold northern summer orbital configurations like that of the last glacial initiation at 116 ka will not take place for at least 30 kyr (Box 6.1). Under a natural CO2 regime (i.e., with the global temperature-CO2 correlation continuing as in the Vostok and EPICA Dome C ice cores), the next glacial period would not be expected to start within the next 30 kyr (Loutre and Berger, 2000; Berger and Loutre, 2002; EPICA Community Members, 2004). Sustained high atmospheric greenhouse gas concentrations, comparable to a mid-range CO2 stabilisation scenario, may lead to a complete melting of the Greenland Ice Sheet (Church et al., 2001) and further delay the onset of the next glacial period (Loutre and Berger, 2000; Archer and Ganopolski, 2005).

Bottom line, we don't have a year 10K problem, we may have a year 30K problem assuming that there remains any ice in the Arctic. Don't bet on that the way things are being driven.

UPDATE: Inel has attracted the Fegel hisself

* Al Gore is stout
** The hockey stick curve was introduced by Mann, Bradley and Hughes in 1998, and since then, although the statistical methodology has been challenged, every other paleoclimate study has shown a similar behavior with improved statistic.
*** The way it works is that orbital changes(Milankovitch cycle) lead to a small amount of warming coming out of the ice ages (that is a so called forcing, something external to the Earth's climate that affects it). The system responds by releasing more greenhouse gases, CO2 (fizzy coke effect) and higher water vapor and melting ice which changes the albedo. If you do it nature's way this takes a couple of thousand years. In that case the CO2 functions as a positive feedback which complete the warming.

Although the primary causes are different, this is completely consistent with increasing CO2 concentrations by any means leading to a warmer atmosphere and surface. The only difference is that we have forced, a ~33% increase in CO2 over 100 years, very fast for geological processes. This is a forcing, because it came from outside the climate system, but the effect is the same. It's very basic stuff. As a matter of fact you expect that CO2 will lag warming coming out of an ice age, because ice ages end not because of initiating CO2 increases, they are accelerated by them

Real Climate goes into more detail

Figure is from the AR4 paleoclimate chapter Box 6.1
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