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re. Circling the Arctic
reposted at WUWT entitled "Arctic Temperatures - What Hockey Stick?"

Followup to comments at WUWT, Jeff Id, Climate Audit forum, and Tamino - work in progress. I'd prefer to keep this out of our forum, as I don't have the time to moderate and I want to keep strictly to the point. Email me direct, please; I will respond.

Are recent records subject to warming distortions? | What general evidence is there for UHI? | What's this about Arctic weather stations? | Is Tamino being fair?

 

Are recent records subject to warming distortions?

Daly was careful to choose stations as far as possible that had long records, had not been moved, and were truly rural.

Many stations designated as rural are contaminated by nearby heat sources - some like Longyearbyen are at "rural" airports. But I cannot yet quantify this enough for my liking.

Here is a blink comparator for Bodø.

Warmists show a trend of the "average" of Arctic temperatures which rises far more than Daly's graphs here. But skeptics point out that there are different versions; the latest version is seriously compromised by being "homogenized" to try to allow for UHI (Urban Heat Island effect). Because of the methods used, this has distorted a longstanding clean well-known record by conflation with anonymous UHI-contaminated records, giving a marked "up" trend that is clearly pretty nonexistent at Bodø. This "correction" adds about 0.5ºC to the twentieth century trend; the total trend the IPCC agrees is only 0.7ºC. In truth, probably a small figure should be SUBTRACTED for UHI from even Bodø's most recent temperature record, thus LESSENING even what trend exists, certainly not heightening it.

In the earlier NASA versions, one finds Daly's data confirmed. But Daly has even more of value: since NASA have now chosen to hide records prior to 1880, Daly's record goes back further, thus providing even longer evidence of natural swings, with no unique severe "hockey stick blade" uptick during the last century.

What general evidence is there for UHI?

Daly again: Here are two very long records from New York State, fairly close to each other.

The UHI effect here seems to be around 2ºC - and that's assuming there is no UHI distortion at West Point.

John Daly has done several graphs to help build up the picture of inadequately quantified UHI distortion (check through the list in What the Stations Say).

What's this about Arctic weather stations?

In considering possible causes for distortions producing non-existent upward trends, one must also remember the loss of stations. This is a particularly serious issue in the polar regions - for instance, just one station, Eureka, now "represents" the whole of the Canadian Arctic - an impossible feat.

Unfortunately, the very design of the most recent weather stations also contains at least one inherent tendency to produce a warm bias. Stations now tend to be sited far closer to dwellings, as they now require electricity, and cabling is expensive. It is also possible that the electricity used produces heat that distorts the records further.

All this produces a recent cumulative effect that is in addition to the Urban Heat Island effect due to the general proximity of dwellings.

Is Tamino being fair?

I've given Tamino a whole page, to properly demonstrate the graphics he criticizes - and to answer his comments. Probably it won't make any difference to Tamino et al - but at least it's there for the record. I emailed his blog: Tamino, I’m honoured that you take notice of me. However, it would have been nice if you’d invited me to respond earlier. Because since you did not, I was naturally a bit peeved and did a whole page on our website – just for the record that you have misrepresented my position and I can respond. However, if you think I’m misrepresenting anything in my response to you, I’d be glad for your response. I try to get things right in the end – engineering quality often starts out flawed and becomes workable by checking out and correcting, in my experience.

Page updated 13th September 2009

 

 

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