2 thoughts on “The Death Of The Hockey Stick?”

  2. The deadly part of the stick isn’t the blade – it’s the shaft.

    The satellite records from 1978-now give us a pretty solid lock on ‘current’ measurements. The surface records 1850-now give us a ‘poor to abysmal’ reading – that is at least based on actual instruments.

    That’s all ‘blade’ time. And, other than the twiddling with the raw data that eliminates the 1930-to-1960 ‘warmish period’, it isn’t all that controversial.

    The ‘shaft’ part starts with Mann’s tree-ring-elimination method. “His what?!?” His method is to basically look at the 10,000 individual trees and start eliminating any that deviate from the (poor quality!) surface records.

    Well, not ‘eliminating’, but assigning weights for the weighted average of effectively zero. Like ‘one-one millionth’. So the alignment for each and every reconstruction (including non-tree reconstructions) is lined up and evaluated across a temperature period – like 1900-1960. Only the top ten contenders have significant weights.

    Just think about that for a second. The Greybill Bristlecone pines, the (upside-down & contaminated!) Tiljander lake sediments, and the Yamal series based off of tree YAD061. 10,000+ individual measurements, but the ones with significant weighting come down to the single digits.

    And yet large swaths of the deprecated tree studies claim correlation with temperature – and have weights of basically zero.

    This allows adjectives “global” and “comprehensive review” etc. while still relying on just a few convenient data points. And… they -are- peculiarly convenient. The ‘Greybill’ site was exhaustively re-examined by Dr. Mann’s own graduate student Dr. Abednah. The correlation between temperature and both the -exact- trees on the pre-1960 study, and a much wider net from the same area both diverge dramatically. This tree-divergence is widespread – and a clear indication that trees aren’t -always- useful proxies for temperature.

    The Tiljander business would sink Mann entirely on its own if he was ever pinned down by a serious interviewer. Two separate issues. First, the paper’s indicated ‘temperature proxy’ direction is -inverse- when compared to temperature. Simply reversing it before throwing it into Mann’s method would be fine – and he claims “That’s irrelevant, the method will invert it if it needs to.” Well enough. The second issue is that there was a massive construction project – and all data beyond that point is even visually dramatically difffernt from the early data. Only the -early- data is even a temperature proxy – the contaminated data was included in the paper for completeness, but when you compare the local temperature records, it is quite clear the later data is bogus. And yet – the bogus data is the portion of the Tiljander series that pop out of Mann’s method.

    And YAD061. The Yamal series has very, -very- few trees as it approaches the present. The whole kerfuffel over ‘other data’ etc. is that there were plenty of other trees in the area that were sampled and measured – but not included in -this- series.

    Sorry Rand for ranting on this. I am still having trouble believing that we’re seriously relegating thousands of scholarly articles by historians about the Little Ice Age and Medieval Warm Period – from Alaska, through America, the Vikings, wheat growth patterns across Europe to Siberia and down through Egypt and India – all of that is “Anecdote” and yet three screwy “proxies” (of 10,000!) say “Flat!” and we bought it.

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