First, the GHOST dataset used to be password-protected since the hard work of building the dataset was devoted to bring together proxy people and model people working on model-data comparisons (note one dataset builder would like to publish first after the painful work undertook instead of making it available to everybody). Once the dataset used as a tool was spread in the literature it certainly should have been available to the community. Occasionally, one fair data digger should admit that a simple mail to the corresponding authors may have led to receiving the dataset directly from the author. This being said, the extended database is now available on PANGAEA thanks to Hannes Grobe, but note it’s a hard work as well to finalize archiving a tremendous amount of data and related information (two months and dozens of mails of correspondence between Hannes and me finally permitted to undertake the archiving of all these data).

On the reliability of alkenones, I am not aware of any publication reporting convincing evidence for a supposed salinity bias on this temperature proxy. By the way, using the term “bias” to describe contrasted trends is misleading once the trends are confirmed by a large amount of regional cores but collected in different localities. Instead of pointing out bias, one should admit that Mg/Ca and alkenones that are well-established – although not perfect – proxies, just bring different stories. I would rather tend to see new rooms for resolving seasonality issues by applying multi-proxy analysis on marine cores.

The seasonal hypothesis we propose in the Leduc paper is a first attempt to reconcile opposite SST trends, especially in the tropics as observed by different proxies. We do not claim that we solve every discrepancy since we come up with a simple conceptual model to explain such contrasted trends that appear to be a global feature at low latitudes. We indeed wrote in the abstract “Although this “ecology hypothesis” fails to explain all of the available results, we argue that any other mechanism would fail to satisfactorily explain the observed SST discrepancies among proxies”. There are enough terms in the paper such as “suggest”, “propose”, “hypothesize” that dismiss any criticism I read in the comments above (AJStrata: “They have not eliminated all other possible sources/causes [...] What is really disgusting (and I mean that seriously) is how this group of so called scientists pawn off a hypothesis as proven fact, then claim no other hypothesis is valid.”)

To tty: “The paper suggests that this is due to the proxies sampling different seasons. I don’t find this wholly convincing since alkenone also indicates rising tropical SST temperatures during the previous interglacial, while all other proxies (palynology, fauna, oxygen isotopes, speleothems etc) I’ve ever heard of agree that temperatures were highest early in the interglacial and then declined.” If long-term climate trends are due to changes in orbital parameters (as somehow admitted for the Holocene period), then one should look into the effect of precession of the climate records. By definition, any climate record bearing a precessional cyclicity has to be seasonally-weighted since there is no change in annual-mean insolation triggered by precession. As alkenones seem to follow boreal winter insolation changes within the tropics, it is not surprising to observe other climate records such as “palynology, fauna, oxygen isotopes, speleothems etc” that are rather summer-sensitive, i.e. will be impacted by an insolation trend that is antiphased as compared to winter. My personal point of view is that one should take care of the seasonality impact on climate geological records, since seasons are expected to be overwhelmingly shaping climate records (speleothems are perhaps the best example).

To say the obvious, the Leduc paper was not purposed to come up with an explanation for why in the IPCC fig. 6.9 the tropics were unconclusive. Rather, the database will be used as a target in paleomodelling experiment projects. The IPCC builds up on the peer-review litterature, but the contrary is generally not.

Steve: thank you for this. I had submitted a request for password access on a previous occasion and had not received any response. I had not pursued the matter. Unfortunately, I’d had little luck in some comparable situations where I had pursued matters.

Because of this emphasis on technical accuracy, issues of morality and politics are usually seen as important, but not a fit topic to discuss here. I will not discuss them, but would like to draw readers attention to a quote from Theodore Dalrymple, which makes the point that technical accuracy is not divorced from morality – indeed, it underlies it. Dalrymple is speaking about the corrosive effect of political correctness and the requirement under some communist societies to claim that ‘everything is fine’, but the words, and the implications, are equally applicable to AGW:

“…When people are forced to remain silent when they are being told the most obvious lies, or even worse when they are forced to repeat the lies themselves, they lose once and for all their sense of probity. To assent to obvious lies is to co-operate with evil, and in some small way to become evil oneself. One’s standing to resist anything is thus eroded, and even destroyed. A society of emasculated liars is easy to control.”

http://www.skepticaldoctor.com/Quotes.html

“confounding director”. Freudian?

I heard that the scorching hot summer in Europe went together with a persistent cold SST spot in the mid atlantic where the low pressure areas are generated normally that bring cool moist summers to Europe.

Wouldn’t low SST obstruct convection and evaporation, causing less cloud forming, latent heat tranport, and hence a lower albedo, with more insolation and hence higher lower atmosphere temperature? And vice versa of course.

Or would basic meteorology not work in paleoclimatologic suppositions?

The Excel files on the Data page of the GHOST project’s home site ( http://ghost.pangaea.de/ ) are password-protected, for some reason.

The data files are accessible if searched for via http://www.pangaea.de/ .