More on the new Canadian temperature “hockeystick”

The Mann and Briffa “hockeysticks” (records of a late 20th century temperature rise) were eventually shown to depend on just a few atypical tree rings, and tree-rings are an unreliable reflection of temperature anyway, so the latest “hockeystick”, based on various creepy-crawlies found in a far-Northern Canadian lake, must be giving the Warmists frabjous joy. As I and various others pointed out yesterday, however, one swallow doesn’t make a summer, and factors other than global warming could account for the changes observed.

Furthermore, evidence that the creepy-crawlies are NOT a good proxy for temperature is readily to hand. The whole point of their claim is that there has been a temperature upsurge just in the last 50 years — and yet we have REAL temperature measurements for that time, and indeed for a century or so before that. So we can test the validity of using creepy-crawlies as a proxy for temperature. And a test shows them to be in fact invalid. They do not measure temperature. As a correspondent observed: “The original article is in PNAS and (like a lot of things in lightly reviewed PNAS) is a joke. Not one reference to real-world temperature records that are nearby and show nothing like what is in the paper.”

Another correspondent draws attention to the fact that the paper depends on the old “correlation is causation” fallacy. They don’t look for alternative explanations of what they have observed. The correspondent writes:

For what it’s worth, two things occur to me.

1. “several types of mosquito-like midges that for many thousands of years thrived in cold climate surrounding the lake suddenly began declining at around 1950″ — Have they accounted for the use of DDT, then? Seems to me that DDT on Baffin Island could have been very popular among trappers and the military in the 50s. Possibly pertinent too:

DDT and its breakdown products are transported from warmer regions of the world to the Arctic by the phenomenon of global distillation, where they then accumulate in the region’s food web. See here. Thus there might be a human impact on this parameter, but of another kind.

Beyond that, though, if the authors are suggesting that CO2 has caused a mosquito or midge shortage up north, they should consult caribou herds, whose route of wandering is traceable to wind direction, so desperate are these animals to escape the floating bloodsuckers.

In the Canadian Arctic, researchers who bared their arms, legs, and torsos in an experiment reported as many as 9,000 [mosquito] bites per minute. See
here

Who knows, then? Changing wind patterns and a consequent shift of caribou migration (the supporting host) or DDT usage might account for the decline of midge bodies in this particular study of Ayr Lake. But CO2?

2. “The Earth is now some 600,000 miles (966,000 kilometers) further from the sun during the Northern Hemisphere summer solstice than it was at the time of Jesus Christ” — A sad example of allegation that’s already become a repeated “fact” simply because no one’s bothered to investigate it. I have, and find no indication that this million km claim is true.

Warmism is very destructive to real science.

EVIDENCE THAT THE CANADIAN “HOCKEYSTICK” IS NOT REPLICABLE

As expected, it is looking very much like a one-off. Below is the abstract of what appears to be a very similar but more cautious study, complete with diatoms and chironomids (midge larvae) but with very dissimilar results.

Similarities and discrepancies between chironomid- and diatom-inferred temperature reconstructions through the Holocene at Lake 850, northern Sweden

By I. Larocque and C. Bigler

Abstract

A quantitative temperature reconstruction using chironomids and diatoms has been attempted from a high elevation lake in northern Sweden (Lake 850). Since 7000 cal. years BP, both chironomids and diatoms recorded similar temperatures (in the range of present-day estimates) but the correspondence between chironomid and diatom-inferred temperatures was highest in the recent Holocene (2500 cal. years BP to the present). Between ca. 9000 and 7000 cal. years BP, inferred temperatures from chironomids were warmer than today (ca. 1–2°C), in accord with other climate reconstruction using pollen, plant macrofossils and oxygen isotope analysis in lakes of northern Scandinavia. In contrast, diatom analysis did not infer warmer temperatures during this period. The insensitivity of diatoms to temperature in Lake 850 between 9000 and 7000 cal. years BP could be attributed to other environmental factors affecting the diatom assemblages through time, especially lake-water pH. Diatom-inferred pH showed a gradual decrease (0.5 pH units) between 9000 and 7000 cal. years BP while it remained more or less constant since 7000 cal. years BP. Changes in lake-water pH acting on diatoms seem to mask the effect of climate, leading to temperature reconstructions that are inaccurate. Ways of disentangling climate and other environmental factors when attempting climate reconstruction should be further investigated.

SOURCE

(For more postings from me, see TONGUE-TIED, DISSECTING LEFTISM, GREENIE WATCH, POLITICAL CORRECTNESS WATCH, GUN WATCH, EDUCATION WATCH INTERNATIONAL, IMMIGRATION WATCH INTERNATIONAL, FOOD & HEALTH SKEPTIC, SOCIALIZED MEDICINE, AUSTRALIAN POLITICS, EYE ON BRITAIN and Paralipomena . List of backup or “mirror” sites here or here — for readers in China or for everyone when blogspot is “down” or failing to update. My Home Pages are here or here or here. Email me (John Ray) here.)