Category Archives: Multiproxy Studies

PAGES2K vs the Hanhijarvi Reconstruction

The PAGES2K (2013) Arctic reconstruction of Kaufman et al has attracted considerable attention as a non-Mannian hockey stick. However, it’s been fraught with problems since day one, including a major re-statement of results in August 2014 (McKay and Kaufman, 2014 pdf), in which Kaufman conceded (without direct acknowledgement) Climate Audit criticism that their results had been […]

PAGES2K: More Upside Down?

Does it matter whether proxies are used upside-down or not? Maybe not in Mann-world (where, in response to our criticism at PNAS, Mann claimed that it was impossible for him to use series upside-down).  But, unlike Mann, Darrell Kaufman acknowledges responsibility for using proxies upside-up. Unfortunately, he and the PAGES2K authors don’t seem to be […]

Okshola: which way is up?

The recent revisions to PAGES2K included a dramatic flipping of the Hvitarvatn varve series to the opposite orientation used in the 2013 version used in IPCC AR5. Together with other changes (such as a partial – but still incomplete – removal of contaminated sediments from the Igaliku series), this unwound most of the previous difference […]

Revisions to Pages2K Arctic

Kaufman and the PAGES2K Arctic2K group recently published a series of major corrections to their database, some of which directly respond to Climate Audit criticism. The resulting reconstruction has been substantially revised with substantially increased medieval warmth. His correction of the contaminated Igaliku series is unfortunately incomplete and other defects remain.

Mann Misrepresents the EPA – Part 1

In today’s post, I will return to my series on false claims in Mann’s lawsuit about supposed “exonerations”. ( For previous articles, see here). One of the most important misconduct allegations against Mann – the “amputation” of the Briffa reconstruction in IPCC TAR – was discussed recently by Judy Curry, who, in turn, covered Congressional testimony […]

A New Alaskan d18O Series

PAGES2K Arctic introduced a lake sediment d18O series from Kepler Lake, Alaska that hadn’t been used in previous studies. Although O18 data is a workhorse of paleoclimate, O18 data from Alaska (or, for that matter, anywhere in the Arctic hemisphere between 90E and 90W – going east) is very scarce. Thus, the appearance of a […]

More on Hvitarvatn Varves

In a previous post on PAGES2K Arctic, I pointed out that they had used the Hvitarvatn, Iceland series (PAGES2K version shown below), upside-down to the interpretation of the original authors (Miller et al), who had interpreted thick varves as evidence of the Little Ice Age. A few days ago, Miller and coauthors archived a variety […]

Evasions and Fantasy at Real Climate

Several readers have asked me to respond to recent comments about me at Real Climate: briefly, Osborn has made one misrepresentation after another and made statements with seemingly complete indifference as to whether he has any basis for making the claims. In respect to Schmidt’s whinge, as Lucia sagely observed a couple of years ago […]

Treeline Changes and Altitude Inhomogeneity

The apparent inconsistency of ring width chronologies with analysis of changes in treeline elevation has long been an issue that I’ve urged specialists to address. Unfortunately Briffa et al 2013 failed to address the inconsistency at Polar Urals, even though they took note of an obsolete Shiyatov article on treeline changes. (More recent work by […]

CRU Abandons Yamal Superstick

Unreported by CRU is that they’ve resiled from the Yamal superstick of Briffa 2000 and Briffa et al 2008 and now advocate a Yamal chronology, the modern portion of which is remarkably similar to the calculations in my posts of September 2009 here and May 2012 here, both of which were reviled by Real Climate […]


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