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by btilly
4773 days ago
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Interestingly when I went looking I came up with http://www.guardian.co.uk/commentisfree/2008/jun/07/climatec... which is a prediction from 5 years ago citing two studies saying that there would be several cooling years ahead. But more fundamentally, the natural variation over a decade is +- 0.2 C. If the warming trend for a century is 2 C, then the warming trend per decade is also 0.2 C. Thus a flat decade is readily explainable by normal variation. If the warming trend is instead 1.5 C per century, then a 15 year stall becomes even more reasonable than a decade had been under a faster rise. The golden question then becomes how this study found a 0.15 C rise in temperature from data over the last decade. I have not read the study. But I know that correctly modeling these things is far more complex than just looking at a long-term average. And given that I know that detailed attempts to produce actual heat budgets for where energy is going have consistently found that the planet has been steadily absorbing large amounts of heat in recent years, I'm inclined to believe their figures over an argument from a temporary stall in global atmospheric temperature. |
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In my skimming of the original article I didn't see where that claim was presented. But if I had to guess, there are at least three ways somebody could accidentally reach that wrong conclusion.
(1) Using something like the woodfortrees link, specify a "From date" year but don't specify an "end date", so you plot, say, from 2002 to "today". The leftmost point on your plot is in January; the rightmost point is in the middle of summer because that's when it is now. Boom, you've got some instant extra warming, assuming you picked a temperature trend influenced by surface thermometer readings.
(2) Instead of looking at actual temperatures, look at a heavily smoothed moving average of temperatures. Or average every decade into a single point and then compare those points. This gives you a plausible excuse to ignore much of the most recent data and the most recent trend ("Tamino" aka Grant Foster often pulls this trick on the readers of his blog Open Mind.)
(3) Instead of looking at the most recent data, google up an old study that ended in, say, 2000 and interpret all talk about "the last decade" as referring to the last ten years shown in that study. :-)
UPDATE: I just thought of another:
(4) Timing. The annual temperature trend is pretty noisy, so over any given ten-year period it might increase or decrease. If you're a "warmist", your favored information sources are going to publish new studies and trumpet their findings whenever the most recent decade now seems to show a big jump compared to the trend it seemed to show in prior years, with headlines like "it's worse than we thought!". So any time this issue comes up, those are the studies/stats that you'll remember and cite.
(the original Mac/PC debates had exactly this dynamic - both Mac fanboys and PC fanboys were generally convinced that their platform was better in all the ways that mattered; their certainty was almost entirely a matter of salience bias and the timing of news release events.)