Spot the Hockey Stick #5 – The Arctic Climate Impact Assessment

Another instalment of our favorite game. This time it’s from the Arctic Climate Impact Assessment, which was published with big fanfare and a slew of scary headlines and quotations in October 2004.

The documents are stowed in the AMAP documents database and contain some of the slickest, glossiest presentations that I can remember. They’ve obviously got plenty of money to produce this stuff.

Anyhow, to show off their presentation skills, they’ve managed to produce the Mann Hockey Stick in 3D in the executive summary. Clearly the use of the Hockey Stick as a totem for climate change is as strong as ever, despite the downplaying of the reconstruction on


  1. Posted Feb 17, 2005 at 7:23 PM | Permalink

    Wrong graphs aside, it’s a beautiful brochure! Even though with those 100 people who did it it’s not so shocking.

  2. Michael Mayson
    Posted Feb 18, 2005 at 1:08 AM | Permalink

    Given the uncertainties and compromises surrounding temperature measurement and the definition of a "global average" I wonder if temperature is the best indicator of climate trend.
    After all, a temperature reading is an indication of a property of a very small volume of material.
    It represents a property of a larger volume only by inference.
    Would it not be better to focus on planetary heat fluxes?
    I am aware that there are a number of satellite experiments in progress and planned to look at this and I would be very interested if someone could point me to a summary of what has been learnt to date.

    John writes: The whole question of what is “global temperature” and what is its relationship to the concept of “climate” is dealt with in Ross McKitrick and Chris Essex’s book “Taken by Storm”. See for more information.

  3. Jeff Norman
    Posted Feb 18, 2005 at 8:19 AM | Permalink

    I have to agree with Michael. The concern of global warming is that the average surface temperature of the world will increase, resulting in changes in climate patterns, that in turn would have an adverse impact on the biosphere (bad weather, reduced habitats, etc.).

    But temperature is really just a by-product of the heat balance of the planet. At best temperature is just a proxy for heat balance measurements which are unavailable.

    If, as the greenhouse theory suggests, less heat is escaping from the atmosphere into space, then the heat energy must be going somewhere else.

    I am not a climatologist. I don’t even play one on TV (or other media), however I love playing with data. In the past I have “played” with MSU and CRU data comparing the year over year temperature differences derived from these two data sets. They seem to be measuring the same same thing, but I am not sure what it is.

    The largest single year increases in the “global” temperature records since 1979 are 0.45°C and 0.46°C for the CRU and MSU data sets respectively. These are large given an “average global” increase of ~0.7°C during the 20th Century.

    The largest single year decreases in the “global” temperature records since 1979 are -0.44°C and -0.49°C for the CRU and MSU data sets respectively. These largest decreases occurred immediately after the years with largest increases.

    For me the question remains, where did the heat for the one year increase come from and where did the heat subsequently go?

    Was the heat suddenly burped up from the ocean into the atmosphere? Was it subsequently lost into space? Or did it somehow magically return to the ocean?

    I do not know. I don’t think anyone actually knows. Because of this lack of knowledge I remain very skeptical of of the claims of the proponents of the Kyoto Treaty.


  4. Steven Holloway
    Posted Jul 21, 2005 at 10:10 PM | Permalink

    It appears from studying the chart that Carbon emmisions have gone from 275 ppm in 1775 to about 365ppm to date. This increase appears to be inconsequential when compared to the 4 fold increase in Methane in our environment from the years 1900 to 1990. It seems we should be more worried about methane than carbon.

  5. TCO
    Posted Sep 11, 2005 at 8:08 AM | Permalink

    The way they plot the carbon (with a displaced zero axis) serves to exaggerate the change (visually).

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