(Part of the How to Talk to a Climate Skeptic guide)

Objection:

In October 2008, Al Gore's science adviser, James Hansen announced yet another "hottest" month on record. After all the alarmist banner headlines sank in, yet another "correction" quietly contradicted this, and October was not particularly warm after all. This is yet another example of why the temperature record can not be trusted.

Answer:

Wow. Where to begin with this one? There are many versions of this myth around already at the time of writing (November 2008) and there will undoubtedly be many more as time goes by. They will not all say the same things so I will try to answer all of the more common memes that come up in this one place.

Firstly, James Hansen is one of the most respected and senior climate scientists working in the field today. His resume [PDF] is long and solid and his position for the last 27 years is Director of NASA's Goddard Institute for Space Studies. Describing him as "Al Gore's science adviser" can only be an intentionally implied disparagement. It both minimizes his expertise and attempts to undermine his credibility by association (because we all know Al Gore is out to lunch, right?). Both of these tactics are common logical fallacies. When an argument is lead by such shallow efforts, it does not leave one very hopeful for what will follow!

Secondly, and perhaps most damningly for this talking point, the alleged "announcement" is complete, 100 percent fabrication. Neither Hansen, nor GISS, ever made any such announcement. Period. The claim they did is is either an outright lie or the willing repetition of an outright lie. You think I am wrong about that? Well, let's have the link, then!

Thirdly, the alarmist headlines are also non-existent. Not too surprising given the absence of any announcement.

OK, so the mountains are an illusion, what about the molehill?

There was indeed an error in the calculated anomaly for October 2008, placing it very high and at a new record. Through a programming glitch of some sort, RealClimate reports:

For many Russian stations (and some others), September temperatures were apparently copied over into October, giving an erroneous positive anomaly. The error appears to have been made somewhere between the reporting by the National Weather Services and NOAA's collation of the GHCN database. GISS, which produces one of the more visible analyses of this raw data, processed the input data as normal and ended up with an October anomaly that was too high.

Nobody's perfect, I think mistakes are bound to happen, especially in such intense data processing projects. The proof of the pudding is what happens next, and in this case the offending data was pulled in under 24 hours (with no premature announcement, remember?) and the error was investigated and corrected. (If only it would end there ...**) So after the correction, how does October 2008 fit into the scheme of things? October 2008 was well above the 1951-1980 baseline average and the fifth warmest October in at least the last 128 years -- very likely much longer.

Does this event really give us reason to distrust the temperature analysis? Well, I think it reminds us that this is a human endeavor and mistakes are always possible, so it is a good idea to double check both the specific process and to compare the result to the many other independent global temperature indicators. However, they all point to the same conclusion.

"Trust, but verify" as the saying goes. After verification, one must still conclude that the long term warming trend is undeniable.

**While I am a firm believer in not judging a blog by its commenters, it is still revealing to see the kind of thinking that lies behind the denialists. Check out these highlights extracted from Watt's Up With That by RealClimate:

"I believe they had two sets of data: One would be released if Republicans won, and another if Democrats won.", "could this be a sneaky way to set up the BO presidency with an urgent need to regulate CO2?", "There are a great many of us who will under no circumstance allow the oppression of government rule to pervade over our freedom -- -PERIOD!!!!!!" (exclamation marks reduced enormously), "these people are blinded by their own bias", "this sort of scientific fraud", "Climate science on the warmer side has degenerated to competitive lying", etc. (To be fair, there were people who made sensible comments as well).

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Skeptic.

"October 2008, yet another phony record" is also posted on A Few Things Ill Considered, where additional comments can be found, and where the author, Coby Beck, is more likely to respond.

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