"For several years Steve McIntyre has warned readers of Climate Audit that an effort has been underway to produce spotty marine data over the past two thousand years and declare it compelling.
As stated in the September 11 TWTW:
McIntyre traced that the assertions that temperatures have been stable up to the industrial revolution come from a set of studies
by an international paleoclimatology group based in Bern, Switzerland, known as PAGES 2k (PAst Global ChangES with 2k referring to the past two thousand years).
The data itself are maintained by NOAA in Boulder.
The most devastating criticism is the deliberate omission of high-resolution, well-established proxy studies of alkenone deposits (produced by marine algae).
These deposits include those in limestone beds and date back millions of years. McIntyre writes:
“But most of all, given that the 60-30S latband [latitude band] is almost entirely (~96%) ocean, it seems bizarre that PAGES 2019 did not use any ocean core proxies,
especially since there are physical formulas for estimating SST [Sea Surface Temperatures] from alkenone or Mg/Ca measurements.
Any conversion of tree ring widths to temperature in deg C is the result of ad hoc statistical fitting, not a universal formula.
Alkenone values have been measured all over the modern ocean and nicely fit known ocean temperatures.
In addition, alkenone values for ocean cores going back to deeper time (even to the Miocene) give a consistent and reproducible narrative.
So, there’s a lot to like about them as a candidate for a “good” proxy.
“While there are numerous high-resolution (10-year resolution) alkenone and Mg/Ca measurements in the North Atlantic with values through the last millennium and up to the present,
to my knowledge, there were not any such series as of PAGES 2013 or PAGES 2017.
(In my opinion, IPCC AR5 [2013] ought to have noted this and suggested that this deficiency be remedied.)
“PAGES 2017 included three ocean core proxy series in the 30-60S, all from offshore Chile.
Their resolutions ranged from 24 to 83 years.
There are some thus far undiscussed puzzles in the PAGES 2017 version of these series – as, in each case, modern values available in the underlying archive series were deleted.
In each case, unsurprisingly, the effect of the deletion was to hide a decline.
In the series of posts on his website, McIntyre extends the coverage of the deficiencies in the PAGES2k data to cover marine data from 60° South Latitude to 30° North Latitude.
This is about 68% earth’s surface (not separating oceans from land).
McIntyre finds no 2000-year period with roughly stable temperatures from the beginning of the Christian era to the beginning of the industrial era.
The deficiencies in these data prompted Donald Rapp, author of Assessing Climate Change: Temperatures, Solar Radiation and Heat Balance (in its third edition)
to post a comment on McIntyre’s website on November 1 discussing a theory of the Climategate hack and the problems with proxy data used by the IPCC:
I think the arguments presented are credible – there was a simple hack most likely based on a simple entry.
But from my point of view, I don’t care if the world’s worst villains were responsible for the hack, nor am I concerned with the degree of sophistication used to get into these secret files.
What does matter is that as of 2009, it is clear that the climate science tribe was strongly biased in favor of alarmism
and built their arguments around dubious data and worse manipulation of the data,
complete with cherry picking some and hiding others,
while at the same time using their influence to squelch alternative views and punish those not in the tribe.
It became clear that the whole science of proxies for past climate was rife with fake news.
Any proxy requires a standardization period when the model can be compared to data.
Then, extrapolation to previous eras requires justification by showing that other variables were comparable during the extrapolated period to those during the standardization period.
I have read dozens of published papers that utilize proxies.
Very few if any show the comparison during the standardization period and/or the basis for justifying extrapolation.
I came to the reluctant conclusion that almost all the proxy data is highly suspect.
SM [Steve McIntyre] penetrated far more deeply than I did into the proxies used by MBH [Michael Mann, Raymond Bradley, & Malcolm Hughes]
and demonstrated the fallacies in both the proxies themselves as well as the methods of processing data.
It seems unimaginable that after all the demonstrations by SM over a decade and more, they are still putting forth their un-science and Mann still is a highly respected leader in the climate field.
The climate gate releases demonstrated not so much the details (they were revealed by SM) as much as the mindset of these rascals.
Altogether, the events of 2009 cast a very long shadow on the periodic UN reports that came out subsequently.
Can you believe anything that the climate establishment publicizes?
Without question, everyone must be wary of using proxy data promoted by the IPCC."