It may seem odd considering how cold it's been in the US recently, and it won't shut down the denial industry for a second, but annual climate data is now in and word is NASA GISS will place 2009 as tied for the second hottest year since modern temperature records have existed. For the southern hemisphere, 2009 was the hottest year ever:
The United States may be experiencing one of the coldest winters in decades, but things continue to heat up in the Southern Hemisphere. Science has obtained exclusive data from NASA that indicates that 2009 was the hottest year on record south of the Equator. The find adds to multiple lines of evidence showing that the 2000s were the warmest decade in the modern instrumental record.
The data is particularly worrisome because it happens at a time when the sun is in a deep solar minimum, or coolest point, in its eleven-year cycle (Solar output only changes by an average of less than one-tenth of one percent over the period, but that small change can still add up when it's distributed over the entire earth's surface for a year or more). The inference being as the sun inevitably swings back toward the maximum, all time record hot years in the near future are sure to follow. A few climate scientists are even predicting that 2010 will be such a year.
Regardless of how 2010 turns out, climate change skeptics are now presented with a problem: The graphs above show how 2009 fits in with the rest of the modern record. The hollow square in the blow up on the right represents 2009. Recall that skeptics widely celebrated the small downtick between 2007 and 2008 as evidence of dramatic global cooling. Consistency would then demand that the 2008 - 2009 uptick, which happens to be slightly greater than the former, represents dramatic warming. That would be a poor interpretation, one year does not a trend make. The point is moot anyway since consistency is not exactly valued by the denial industry. But deception is their bread and butter.
Possum Comitatus has a great write up of one such shenanigan recently used by some loudmouthed Australian skeptics which should really be enjoyed in its entirety:
[A] a lot of this pseudo-statistical arsehattery that gets passed off as evidence in any climate change debate (or any debate that contains numbers and lots of politics, sadly) tends to come from the loudest voices involved in that debate.... which also generally happen to be the most ignorant.
The gist of it involves a quantity used in stats called a moving average. All you need to understand here is that a simple moving average (SMA) tends to smooth out fluctuations on a graph, the average lags the actual data, and the longer the period of the moving average the more the data is smoothed out and the greater the lag. They're particularly popular among technical stock and futures traders as shown left by my friends at LearnForExPro.
Now, let's say you're a climate change denier, and you've been waving around a chart showing a moving average touting it as evidence for global cooling. Odds are you've cooked the average to get the best picture you can already. But now, all the sudden, new data comes in and when you put it into your chart it reverses the trend you've been embellishing. What to do? Why, lengthen the moving average of course! Make it a longer period until it smooths out and lags the new data so much that the chart jives with your cooling trend bias! Possum Comitatus makes a persuasive argument that that's exactly the kind of cooked graph one mealy mouthed denier named Andrew Bolt is trying to exploit.
The irony: not only has Bolt made a habit of shooting his mouth off about his inerrant self-awarded expertise -- despite having no formal scientific training in any field of science whatsoever -- for the past month he and his pals took a few words from some stolen emails wildly out of context and brandished them as evidence for a climate change conspiracy. The words that Bolt and company objected to the most as evidence for such a conspiracy happen to be "trick ... to hide the decline." I shit you not.