Posted on 11/29/2006 2:23:37 PM PST by blam
Climate change sceptics lose vital argument
29 November 2006
From New Scientist Print Edition.
Zeeya Merali
The "hockey stick" graph, which shows a rapid rise in world temperatures over recent decades, has been both poster child for the dangers of human- induced global warming and prime target for climate change sceptics. They cite an anomaly in the graph - it does not record a dip in temperature between 1200 and 1850 - as reason to ditch the whole thing. Now new data may help explain why the graph does not record the "little ice age".
Ocean currents in the North Atlantic, dominated by the Gulf Stream, usually keep winter temperatures in western Europe mild by carrying warm water north from the tropics towards Europe and heating the westerly winds travelling from North America. Climate scientists have suspected that a weak Gulf Stream may have caused the little ice age, but until now there has been no direct evidence for this theory.
Jean Lynch-Stieglitz at the Georgia Institute of Technology in Atlanta and her colleagues calculated the strength of the Gulf Stream during the little ice age by looking at marine fossils in sediment cores taken from the Straits of Florida. Ocean circulation is driven by variations in water density caused by differences in temperature and salinity. These variations also affect the ratio of oxygen isotopes in marine fossil shells. By measuring these isotope ratios, the team calculated that the Gulf Stream was 10 per cent weaker during the little ice age (Nature, vol 444, p 601).
(Excerpt) Read more at newscientist.com ...
But it doesn't show up in Mann's interpretation of proxies for North America either, even where the cooling was clearly in effect.
The equations the researcher used to produce the "Hockey stick" do so no matter what data points are used. The HS graph has been thoroughly debunked numerous times by legitimate climatologists, who weren't attacking it just because it didn't reflect the little ice age, but because its whole methodology is wrong.
How is the argument lost? Just because they have some sketchy proof that supports their argument, hardly settles it. The radical climate change 'scientists' tend to brush off any criticism with the flimsiest of proof.
Including when you take the data from the middle and put it at the end and further randomly shuffle its sequence.
"Proxies" - another word for "models"?
Proxies are datasets that represent other data. A typical one is tree-ring widths being used as a proxy for temperature. Unfortunately, tree ring width responds not only to temperature, but rainfall (water in the soil), relative humidity, CO2 levels, vermin outbreaks, blights, mineral availibility changes, cloudiness/overhanging trees, as well as other things. Some of Mann's proxy data is composed only of a couple of trees. He by the way didn't derive the data, but claims that he came up with new ways to statistically treat it so as to derive patterns that weren't clear before. He is not a statistician.
The HS also leaves out the heat wave about 1000 years ago.
This is a basic term in the debate. A proxy is any natural measurement that substitutes for the direct measurement of temperature in the time before weather records were kept with thermometers, which is only about the last 150 years. Tree rings and fossil distribution are examples of proxies.
Even more than that, the datasets used were selected by computer processing that searched for a pattern, then used in unbalanced ways (Bristlecone/foxtail data that gives them 390 times the weight as other data sets that he claims also show the same thing, but which when removed so no hockeystick pattern).
An NAS study noted that some of the important proxy studies that were used also have apparently no record of how they were collected or where from, and the original data from which the proxy sequences were derived were not archived, so no checks can be made for their accuracy either.
A consistant theme that has been discovered is that the "peer review" in climate science studies has never involved checking the math. When MacIntyre and McKitrick asked to see the information that was forwarded by various "peer-reviewed" journals, more than one editor claimed that no one had *ever* asked for the data so that the math could be checked (citing various times they'd been editor, including some over 20 years), or to determine if the processes described in the paper were in fact what duplicable. Who "checks the math"? Basically just associates of Mann and Jones.
Thanks professors!
proxy = "direct measurement substitute"
I want to see a year by year (or better) plot of CO2 concentration vs absolute temperature and the amount of correlation between the two. This is what the current argument amounts to, but the data are never shown. They could even try some data time shifting in case there is a lag between the high CO2 and the high temps. Of course if the temps lead the CO2, well they have a lot of 'splainin' to do.
Just go ahead and establish a climate department to guarantee employment for all these dems.
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