Some essential history of IPCC global warming from 20 years ago.

Over at the matchless blog Wattsupwiththat:

Look for two comments by Mohib (21:33:01) on 1st Feb – I thought Mohib’s questions were important enough to try and explain the history .

Jones et al 1986 did indeed reject 38 stations from their Northern Hemisphere study. Note UHI not actually mentioned in the 1986 Table 1 – but no doubt covered under “non-climatic warming trends” – so a nuance there compounded by PDJ ref to “affected by urbanization” in the ClimateGate mails 1184779319.txt link at Watts.

Nth Hem Journal paper pdf downloadable here

TR022 Nth Hem documentation book partly online with 2 tables showing the breakdowns of their station numbers in each homogenization category.
38 stations UHI affected out of the thousands of NH cities is somewhat laughable and the paper should have been sent back by the editor or reviewers. But Jones could say that other UHI affected data were caught up in other checks of his and rejected for other reasons, eg. Category D maybe.

BTW Geoff Jenkins was one of the original 1990 IPCC authors and you might expect would know these things.
In the case of the Jones et al 1986 Southern Hemisphere Journal paper downloadable and TR027 book fully online.

Jones et al found only 3 (yes three) UHI affected stations to reject. Even more surreal than 38 – 3 out of what, 120 plus major cities in the Sth Hem.

So there are a few “nuances” to comprehend in the statements such as “On the one hand in 1986 he knows UHI affects the temperature..”.

IMHO Jones et al 1986 spoke and did less than the bare minimum required to be able to claim that they had adequately dealt with the UHI in global T data.

There was presumably some disquiet remaining in climate circles after the 1988 publication of Wood’s critique of Jones et al 1986. Otherwise, how do you explain the need for the Jones et al 1990 Letter to Nature at al ?

In the 1990 Letter to Nature they compared purportedly rural series from 3 regions, Western USSR, Eastern China, Eastern Australia – with their grid point trends from those same regions and claimed to prove that negligible UHI effect remained in their grid point trends – a conclusion the IPCC and UKMO has quoted ever since.

In fact what happened IMHO (and I did share in a work checking what they did in Eastern Australia) – was that their Rural series contained significant UHI amplification in the trend – hence they were able to demonstrate tolerable agreement with their grid points trends which also carry UHI contamination.

So Mohib, when you say above; “But then in his 1990 paper he takes the position with Wang that UHI is not a factor in temperatures.” Can you see now that is not a fair summing up of the situation.

In fact Jones et al 1990 was purporting to demonstrate that Rural series had similar trends to his grid point series – ergo by their reasoning there can not be significant UHI effect in either. I hope that that explain it clearer.

Jones et al 1990 is now further unraveling helped along by Doug Keenans persistence and events revealed in Climategate emails. That all these prominent co-authors lent their names to the shoddy 1990 Letter to Nature is a classic case of IPCC science at work.

12 thoughts on “Some essential history of IPCC global warming from 20 years ago.”

  1. Thanks Warwick. I’m just a lay person on these matters, so please forgive me if my questions are simplistic.

    If I understand from your explanation, in 1986 Jones did a poor or superficial job in dealing with UHI and then in 1990 attempted to prove UHI is a non-issue in order to respond to Wood’s 1988 paper.

    Now in the climategate e-mail I cited, Jones confirms he removed stations due to UHI and so, leaving aside whether this was done poorly or superficially, it clearly betrays Jones considered UHI as a relevant factor (else why remove any stations) and so then why in 1990, with WANG, why does he then try to show UHI is a non-issue, irrespective of the issues of the Wang paper Keenan raises?

    In other words the contradiction I can’t figure out is not about Keenan’s problems with the 1990 paper, nor about the Woods or other problems 1986 papers, but the mere fact he attempted to account for UHI in 1986 because he knew it was a factor but in 1990 he tries to show UHI is not a factor. I hope I’m making sense and not missing something obvious here.

  2. I think you have to separate clearly what people SAY – from what people DO.
    In 1986 despite what Jones et al said – despite peer review – legions of UHI affected stations such as Miami, Atlanta, Los Angeles, Irkutsk, Sydney – all walked their way into IPCC global trends carrying their UHI’s with them and are still there in the latest UKMO release.

    In 1990, despite all the statements over the years by Jones et al and the IPCC that their Rural series had insignificant UHI – which by their reasoning proved that their 1986 grid point trends likewise must have had insignificant UHI – the facts are increasingly emerging that both series, 1986 grid point and 1990 Rurals – each carry significant UHI contamination.
    So the IPCC edifice was erected 20 years ago on largely false foundations where global T trends are concerned.
    You are not going to necessarily more closely understand the truth by only examining words that Jones et al uttered here or there.

  3. A common assumption is made by Jones, GISS, NOAA and others that there is no UHI effects in their so-called rural stations (population less than 10,000). However, Oke (1973), Turok(2001) and others have shown that even small towns have an UHI. let’s use Turok’s formula for the UHI:

    T = 1.42*log (pop) – 2.09

    where T is the increase in temperature for a town with a poulation (pop).

    This can be converted to a trend between two times with a population of “poplate” and “popearly” as:

    dT = log (poplate/popearly)

    Now consider two cases, a town which increases in population from 1000 to 3000 and a city which increases in population from 1 to 2 million over the same time. The net increases in temperature are:

    dT (town) = 1.42 log(3000/1000) = 0.68 C
    dT (city) = 1.42 log (2000000/1000000) = 0.43 C.

    Thus, it is possible that towns can have even greater warming trends than cities. Just saying the warming trends in cities is the same or less than warming trends in so-called rural locations is proof that the UHI is unimportant is nonsense.

    It is important that truly rural locations (such as Armagh, Ireland) be found and used for monitoring trends. This requires inspection and evaluation of the stations one by one.

  4. Warwick

    Roger Pielke (Snr) has just posted an interesting article contesting Jones assertion that London (UK) has experienced no increasing UHI effect since 1900.

    As you have pointed Australia is perhaps the ideal location to calculate UHI effect.

    Has there been any independent studies for major Australian cities?
    Added by WSH 6th Feb: The pdf paper I have linked to is not the “Past and projected trends in London’s urban heat island” by Robert L Wilby in Weather 2003 vol.58 (no.7) – but it is probably similar.

  5. Martin, my article last month “How can it serve the Australian national interest by having the BoM mislead us ?” has a link to web pages describing the Melbourne UHI and then there is this 2001 paper by Melbourne University and BoM people.
    Also in 2001 the same authors discovered how easy it was to see the UHI in tiny Australian country towns, something the BoM was reluctant to see when I tried to tell them in 1991 (see timeline refd to below)
    These are the most recent Australian examples I can think of.
    My 11 Dec article gives a timeline of work circa two decades ago relevant to your question. You can see that the BoM in 1990 specified a sizeable UHI response in Australian capital city data.
    Then in 1991 I circulated my draft paper “Heat Islands in Country Towns – South Eastern Australia” which pointed out several ways the BoM temperature records could reveal the UHI in very small towns. However a BoM series from Eastern Australia which they purported to be “Rural” – was being used in the now famous Jones et al 1990 Letter to Nature. This “Rural” series included many centres large enough to carry a substantial UHI and I recall the 49 sites averaged population was ~5,000.

  6. Warwick

    Thanks for the links. As a point of interest there seems to be a discrepency in the population size of towns in some GISS station data and the recorded population size of the same towns shown from other sources.

    When I’ve checked it out better I’ll give you my findings.


    Martin J

  7. Martin, I have just quickly checked a few of the GISS populations and Sydney, Melbourne, BA, are unchanged from the first GHCN pop numbers that came out in ? 1992 ?. There are internet sources for much superior and updated pop numbers including sites that give you a time series of increases / decreases for places. When I made this Sth Hem file, I just inserted the GHCN pop numbers into the Jones et al 1986 Sth Hem station file. I have written something updating pop numbers but can not find it just now.
    Added a few mins later. I drew attention to the inaccurate GHCN pop numbers in my critique of the Easterling et al 1997 paper on global DTR.
    The best web source for global population stats I found a decade ago is now named World Gazetteer

  8. Warwick

    Again thanks. The populations estimates of the GISS sites I have checked so far are all underestimates: I suspect most of them will be.

    Forgive me for being naive but I’ve being trying to access CRU data. In particular I want to see in a tabular form the land stations used in its global temperature records. Following CRU website links I just keep on coming to this site below and then the trail goes dead.

    Is it just me?

    I know I can download data from the address below but I can’t easily relate data to a particular station.

    For all its faults, GISS presents its data in an accessible manner. In comparison, CRU is a nightmare to unravel.

    Or, is it me not doing the obvious?


  9. That is an interesting map Bernd – from before the high rainfall years post WWI to 1960’s – I must do some comparisons when time allows.
    Martin, I have CRU station data files for download plus most of the published papers, up to the 1999 version that was secreted in the ClimateGate FOIA file. Then of course there are the partial CRUT3 station data newly released by UKMO in two tranches, Dec 2009 and Jan 2010. Scroll down at this page. They seem to have most stations I want to look up.

  10. Warwick,
    any knowledge on Brazil temps. Claims by ABC of 46.3C in Rio this week seem a little far fetched. Have not been able to track these claims past the original AFP story and I smell a rat. Official(?) INMET temps for Sunday to Wednesday: sun 7/2/2010 40.4; Mon 8/2/2010 40.7; Tues 9/2/201040.5; and Wed 10/2/2010 38.3

    See for more.
    Original story at

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