Category Archives: Proxies

The Ocean2K “Hockey Stick”

The long-awaited (and long overdue) PAGES2K synthesis of 57 high-resolution ocean sediment series (OCEAN2K) was published a couple of weeks ago (see here here). Co-author Michael Evans’ announcement made the results sound like the latest and perhaps most dramatic Hockey Stick yet: Today, the Earth is warming about 20 times faster than it cooled during the past 1,800 […]

Important New North American East Coast Proxy Data

One of my long-standing interests is the location of ocean sediment series that enable apples-to-apples comparison of the 20th century to the mid-Holocene.   These are not nearly as common as one would think.   Ocean sediment series covering the Holocene typically stop prior to the 20th century due to core recovery problems and, on […]

Ground-truthing Marcott

The MD99-2275 core offshore Iceland is a very high-resolution ocean sediment core, results of which over the past millennium have been discussed here from time to time. Alkenone and diatom results for the last millennium have been available for about 10 years. MD99-2275 results were used in PAGES2K Arctic and Hanhijarvi 2013, also Trouet et […]

Sheep Mountain Update

Several weeks ago,  a new article (open access) on Sheep Mountain (Salzer et al 2014 , Env Res Lett) was published, based on updated (to 2009) sampling at Sheep Mountain. One of the longstanding Climate Audit challenges to the paleoclimate community, dating back to the earliest CA posts, was to demonstrate out-of-sample validity of proxy reconstructions, […]

New Data and Upside-Down Moberg

I’ve been re-examining SH proxies for some time now, both in connection with PAGES2K and out of intrinsic relevance.  In today’s post, I’ll report on a new (relatively) high-resolution series from  the Arabian Sea offshore Pakistan (Boll et al 2014, Late Holocene primary productivity and sea surface temperature variations in the northeastern Arabian Sea: implications […]

Rosenthal et al 2013

There has been considerable recent attention to Rosenthal et al 2013: WUWT here, Judy Curry here, Andy Revkin here. The article itself presents a Holocene temperature reconstruction that is very much at odds both with Marcott et al 2013 and Mann et al 2008. And, only a few weeks after IPCC expressed great confidence in […]

Steig’s Bladeless “Hockey” Stick

In a recent RC post entitled “Ice Hockey” and a recent Nature article, Steig and coauthors have introduced a novel and very baroque “hockey stick”, one without a blade. A true Halloween of horrors: in addition to Gergis’ zombie hockey stick, the bladeless Hockey Stick of Sleepy Hollow is now at large. The appearance of […]

New Light on Svalbard

In 1997, the 121 m Lomonosovfonna ice core was drilled in Svalbard. As of mid-2009, when Hu McCulloch and I wrote CA posts on this core, nothing had been published on O18 values prior to AD1400 nor had any Lomonosovfonna data been archived, even for the post-1400 period. Both Hu McCulloch and I, in separate […]

The Impact of TN05-17

TN05-17 is by far the most influential Southern Hemisphere core in Marcott et al 2013- it’s Marcott’s YAD061, so to speak. Its influence is much enhanced by the interaction of short-segment centering in the mid-Holocene and non-robustness in the modern period. Marcott’s SHX reconstruction becomes worthless well before the 20th century, a point that they […]

Alkenone Divergence offshore Iceland

The longest very high-resolution alkenone core that I’m aware of is Sicre et al’s MD99-2275 (plus splices) from offshore Iceland (67N 18W). It is 4550 years long, its most recent value is 2001AD and its resolution is 4 years. Marcott used nearby core JR51GC-35 (also at 67N 18W), also an alkenone record, which had a […]


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