From: D.J. Keenan
To: Science and Technology Committee (UK Commons)
Sent: 1 December 2010 16:34
Subject: Reviews into the Climatic Research Unit’s E-mails at the University of East Anglia

Pursuant to the reviews of the Climatic Research Unit at the University of East Anglia, oral evidence was heard from Lord Oxburgh, on 8 September 2010, and from Sir Muir Russell, Vice Chancellor Edward Acton, and Pro Vice Chancellor Trevor Davies, on 27 October 2010. Each hearing considered the fraud allegation against CRU Professor Phil Jones. The allegation was made by me. The following describes some issues that pertain to the allegation, and proposes a means of resolution.

The 1990 study
In 1990, the following study was published in the leading scientific journal Nature (note that Jones is the first author). Jones P.D., Groisman P.Y., Coughlan M., Plummer N., Wang W.-C., Karl T.R., “Assessment of urbanization effects in time series of surface air temperature over land”, Nature, 347: 169–172 (1990).

This study concerns an issue with measurements of global temperature. As a simple example of the issue, consider a thermometer in the middle of a large field. Suppose that there was a city nearby, and over time, the city expanded to replace the field with asphalt and buildings. Then the temperatures recorded by the thermometer would tend to be higher, because asphalt, buildings, cars, etc. give off extra heat.

Many thermometers used by weather stations are in areas that have undergone urbanization. Thus, such thermometers might show temperatures going up, even if the global climate was unchanging. It is widely accepted that some of the increase in measured temperatures during the past century is due to many weather stations being located in areas where urbanization has occurred. A critical issue is this: how much of perceived global warming is due to such urbanization effects?

The latest (2007) assessment report by the Intergovernmental Panel on Climate Change considers this issue The IPCC does not do original research itself; rather, it assesses research previously published in scientific journals. The IPCC assessment of the urbanization effects concluded that such effects are insignificant overall. One of the main studies cited by the IPCC to justify that conclusion is the 1990 study of Jones et al. The study of Jones et al. looked at urbanization effects in eastern China (as well as eastern Australia and western Russia). It found that urbanization effects there were insignificant. Eastern China has had much urbanization; so if the temperature measurements from there were essentially unaffected by urbanization, then that would suggest the temperatures records from other countries around the world were also little affected, in general. Hence urbanization effects are probably insignificant globally.

The study of Jones et al. is not the sole study relied upon by the IPCC report for its conclusion about the global insignificance of the urbanization effects. Hence even if the study were wholly invalidated, that would not imply that the conclusion was unsupported. On the other hand, arguments made in some of the other main studies have been strongly criticized (both in the peer-reviewed literature and on scholarly blogs). The Russell report rightly states that the study of Jones et al. “is important”.

Fraudulent claims
A problem with analyzing temperature measurements from weather stations is that the stations sometimes move, and that can affect the measurements. For example, one of the stations used in the 1990 study was originally located upwind of a city and later moved, 25 km, to be downwind of the city; such a move would be expected to increase the measured temperatures, because a city generates heat. It is obvious that when a station moves, the temperature measurements from before the move are not, in general, directly comparable with the measurements from after the move.

The 1990 study of Jones et al. claims that the weather stations that were studied “were selected on the basis of station history: we chose those with few, if any, changes in instrumentation, location or observation times”. That claim is essential for the study.

Jones et al. asserted that they obtained the Chinese data from a report that was jointly published by the U.S. Department of Energy and the Chinese Academy of Sciences. The DOE/CAS report states that its purpose is to present “the most comprehensive, long-term instrumental Chinese climate data presently available”. The report also states, though, that for a majority of the stations studied by Jones et al., “station histories are not currently available” and “details regarding instrumentation, collection methods, changes in station location or observing times ....are not known”. For a minority of the stations, histories are available: over half of those had substantial moves. Thus, there is strong evidence that the claim of Jones et al. to have selected stations on the basis of their histories is fraudulent.

Potential problems with the claim of Jones et al. were first raised on the Climate Audit blog of Steve McIntyre. I subsequently investigated. It became clear that fraud had occurred, but that Phil Jones was innocent: the evidence strongly indicates that, for the Chinese data, Jones trusted and relied upon one of his co-authors, Wei-Chyung Wang.

Wang is a professor at the State University of New York at Albany. In 2007, I filed a formal allegation of research fraud with the University. Details are given in a peer-reviewed article that I published in the journal Energy & Environment (2007), entitled “The fraud allegation against some climatic research of Wei-Chyung Wang”. The University conducted an investigation, which concluded that Wang was not guilty. There were, however, serious procedural irregularities during the investigation. For example, I was not contacted during the investigation: a breach of the University’s own policies, U.S. federal regulations, and obvious natural justice. Moreover, when asked to produce the station histories, Wang claimed, in effect, that he had plagiarized the work and that the person from whom he had plagiarized had since lost the information; yet the university ignored the admission of plagiarism. Details are on my web site.

The U.S. Congress’ Committee on Oversight and Government Reform has contacted me about the irregularities in the investigation. In November 2010, the Committee informed me that it is considering whether to investigate the matter. Final status of the allegation against Wang thus remains to be decided.

IPCC misrepresentation
Although Jones was innocent in 1990, he was no longer so by 2001, when the following research paper was published (note that Jones is one of the authors). Yan Z., Yang C., Jones P., “Influence of inhomogeneity on the estimation of mean and extreme temperature trends in Beijing and Shanghai”,
Advances in Atmospheric Sciences, 18: 309–321 (2001).

The paper of Yan et al. studied two weather stations, one in Beijing and one in Shanghai. The Beijing station had five locations spread over 41 km. The Shanghai station had only a single move, but that move caused a doubling of the long-term warming trend there (according to Yan et al.). The station movements imply that the temperature measurements from the stations cannot be directly used in analysis, as discussed above. Yet the measurements had been used in the analysis of Jones et al. (1990). And given that this problem arose for both the stations that were studied by Yan et al., then it must be suspected for at least some of the other stations used in 1990.

Thus, by 2001, Jones must have known that the 1990 study should not be relied upon. As the lead author of the 1990 study, Jones should have then tried to have had the study retracted: it is clear that that is the ethical thing to do. Indeed, the UK Research Integrity Office now has guidelines stating that a retraction may be necessary “when there is clear evidence that the reported findings are unreliable, either as a result of misconduct, such as fabrication of data, or honest error, for example, miscalculation or experimental error”. Jones, however, did not try to have the 1990 study retracted.

In 2007, the IPCC published its most-recent assessment report on climate change. The IPCC reports are widely considered to be the most authoritative assessment of the science of global warming. For the 2007 report, there were two scientists with final responsibility for the chapter in the report on “surface and atmospheric climate change” (here “surface” refers to the surface of the Earth, i.e. where people live). Those two were Phil Jones and an American colleague, Kevin Trenberth.

The chapter of Jones & Trenberth cites the 1990 study for its assessment of the issue of urbanization effects. Thus, in 2007, Jones was responsible for having the IPCC cite the 1990 study even though he knew that the study should not be relied upon. This constitutes fraud - fraud in the writing of the most important reference that there is on global-warming science.

On 19 June 2007, I e-mailed Jones about this, citing Yan et al. and saying “this proves that you knew there were serious problems with Wang’s claims back in 2001; yet some of your work since then has continued to rely on those claims, most notably in the latest report from the IPCC”. I politely requested an explanation. I did not receive a reply.

In August 2007, I submitted a draft of my article on these allegations to the journal Energy & Environment. The journal editor then sent the draft to Jones. Jones replied with many comments, but he did not attempt to rebut the allegation against him.

On 2 February 2010, in the wake of Climategate, The Guardian published a front-page story that reported on my allegations. The Guardian is a major advocate for global warming; yet the report was highly positive. The story was re-reported around the world. Later that day, the University of East Anglia issued a press release to clarify some issues. Yet the press release did not attempt to rebut the allegation.

Jones has never publicly attempted to deny the fraud allegation against him.

Note that the allegation against Jones is separate from the allegation against Wang. The allegation against Wang relies on the DOE/CAS report. The allegation against Jones is independent of that and relies on the paper of Yan et al.

The 2008 study
In 2008, Jones and two colleagues (neither of which was Wang) published a study that claimed to verify the conclusion of the 1990 study. Jones, and others, have since cited the 2008 study to argue that issues with the 1990 study are therefore immaterial. The 2008 study, however, relies upon the same station histories as the 1990 study. The histories that are not extant. Indeed, Jones discussed my fraud allegation in an interview with Nature (published on 15 February 2010), and in the interview Jones acknowledged that the histories had been lost long ago. In the same interview, however, Jones reasserted that the 2008 study verified the conclusions of the 1990 study - which is obviously impossible.

Moreover, in 2008, Wang made a submission to the University at Albany during the university’s investigation of my allegation against him. His submission (which was leaked as part of Climategate) included a letter from a colleague in China who co-authored the DOE/CAS report. The letter stated that the relevant histories had been lost long ago. Indeed, it is manifest that if the histories were available in 2008, Wang would have produced them to defend himself.

Jones’ story about the 2008 study is plainly false. Jones changed that story in a second interview with Nature (published on 15 November 2010). In the second interview, Jones claimed that the histories had not been lost, but “the authorities [in China] have not released the full station-history data”. Jones’ change of story seems highly suspicious. Moreover, the changed story has a problem: what reason do the authorities have for not releasing the histories? The histories are not state secrets; their release, if they were extant, would benefit science; and CAS undertook a project with DOE to publish them.

Oxburgh and Russell panels
The Oxburgh panel had, as its remit, to assess the integrity of work done at CRU. The allegation that I made against Jones is the sole explicit allegation of fraud that has been made against anyone at CRU. Yet the report of the Oxburgh panel does not consider the allegation. Indeed, Lord Oxburgh stated, when giving oral evidence to the Committee on 8 September 2010, that he did not recall looking at the allegation.

The Russell panel did consider the allegation: Section 6.6 of their report is devoted to this. Neither that section nor any other section of their report, however, cites Yan et al. In other words, the Russell panel did not consider the evidence for the allegation.

The Russell panel claimed, though, that the 2008 study by Jones et al. “verified the original conclusions for the Chinese data”. As discussed above, this claim is extremely dubious. Additionally, my allegation is that Jones committed fraud. The allegation does not concern the validity, or otherwise, of the 1990 conclusions. If those conclusions were invalid, that might potentially have consequences for global-warming science, but it is of little consequence for the central issue: the integrity of Jones’ research.

The panel further claimed that Wang being found not guilty by the University at Albany implied that Jones was not guilty. As discussed above, the allegation against Wang is independent of the allegation against Jones.

It is also notable that the Russell panel had, in its remit, the investigation of e-mails that were released in Climategate and that three of those e-mails included copies of my e-mail to Jones on 19 June 2007, which cited Yan et al. and requested for an explanation for his actions (the e-mails were #1182342470, #1182346299, #1182361058). If every member of the Russell panel read all the Climategate e-mails, as Sir Muir asserted in his oral evidence to the Committee on 27 October 2010, then surely they would have seen the reference to Yan et al. That is particularly so given the publicity that my e-mail to Jones received. For example, the Associated Press had a report on the Climategate e-mails in December 2009. That report highlighted my e-mail to Jones as one of the most significant (though regarding Wang rather than Jones). The report was apparently published in over 1000 newspapers around the world, often of the front page. A Climategate e-mail given that much publicity would be expected to have gotten the attention of a panel investigating the Climategate e-mails.

Conclusions
From this summary account, two main conclusions emerge. First, there is good evidence to support the allegation that Jones committed fraud in some of his research - including research which influenced a chapter of the principal report upon which governments rely for a scientific assessment of global warming. Second, the evidence for the allegation was not considered by either the Oxburgh panel or the Russell panel; indeed, it has not been properly investigated by any competent and authorized body.

It would be much in the public interest if the Committee were to commission an investigation.

If there is to be an investigation, I believe that this should not be undertaken by a scientist or other academic: because scientists generally seem to be reluctant to find one of their own guilty. As evidence, consider that there are tens of thousands of non-medical scientists in the UK; yet in the past quarter century, there do not seem to have been any convictions for fraud. Such a record is not credible: even among much smaller groups of highly respected people - police detectives, Catholic priests, members of parliament - frauds do occur. The evidence against Jones can be understood without scientific training. If there is to be an investigation, then, I suggest that it be undertaken by someone skilled in the rules of evidence, such as a senior judge or barrister. 

UPDATE: Lord Christopher Monckton reports from Cancun that the Obama administration has quietly committed 1.5% of our GDP to the world climate crusade. Please contact your senators and congressmen/women and protest this misguided and even “illegal” action. The senate has to ratify any such agreements according to our constitution and congress has to approve funding.

Thanks to Wikileaks, everyone here in the Manana Republic of Mexico now knows just how much bullying and arm-twisting the administration of Barack Obama in the United States applied to various countries around the world so that they would (and did) sign up to the Copenhagen climate accord.

Without that pressure, nothing at all would have happened at Copenhagen this time last year, and “the Process” - the interminable round of flatulent annual climate conferences in exotic locations at taxpayers’ expense - would have tipped into the gulch forever.

The hard Left has learned the hard way that democracies do not welcome it and, in the end, will reject it. So the climate extremists have abandoned last year’s attempt, in the now-defunct September 15 Copenhagen Treaty draft, to install overnight an unelected world government consisting only of themselves, with unlimited powers of taxation, economic and environmental regulation without representation, as well as control of all formerly free markets worldwide, all in the name of Saving The Planet (which, of course, was triumphantly Saved 2000 years ago and does not need to be Saved again).

Instead, the Martini Marxists dancing the night away doing the Cancun Can-Can with the 25 pneumatic bunny girls in the newly-opened Playboy Casino on the ocean-front strip in Cancun have decided to copy the bureaucrats of the European Union, whose crafty, crabwise coup d’etat over the last three or four decades has transferred all real political power, little by little, treaty by treaty, to the dismal dictatorship of Brussels.

Though there is a toothless democratic fig-leaf in the shape of the European “Parliament”, all decisions in the EU are in fact taken by a couple of dozen faceless, overpaid Kommissars (that is the official German mot juste for them) - faceless because they meet behind closed doors and then emerge to promulgate their “Directives”: on average, one every three hours, day and night, Sundays and holidays included, 365 days a year, 366 days on leap-years.

In Europe, democracy has gone. Perma-Socialism has quietly supplanted it. If demolishing democracy worked there, the enviro-zombs’ reasoning goes, it will work on a worldwide scale, if only the crumbling pretext for global tyranny - the supposed need to prevent catastrophic “global warming” - can be kept going for long enough even though most ordinary voters (in those nations lucky enough to have them) have seen through the scam long since.

The Process works like this. A multitude of long, inspissate, obfuscatory, obnubilating, obscurantist draft agreements are circulated, always a day or two late for delegates to find out what they have actually agreed to. The daily timetables for the various “working” sessions of the conference are never available until breakfast-time on the day, allowing no scope for planning the day. By these means, most delegates are kept permanently and completely in the dark.

Here is a typical paragraph from one of these leaden documents:

“The SBSTA welcomed the report (FCCC/SBSTA/2010/INF.10) on the second workshop of the work programme on revising the “Guidelines for the preparation of national communications by Parties included in Annex I to the Convention Part I: UNFCCC reporting guidelines on annual inventories” (hereinafter referred to as the UNFCCC Annex I reporting guidelines), held in Bonn, Germany, from 3 to 4 November 2010, which was organized by the secretariat as requested by the SBSTA at its thirtieth session.”

Try to read several hundred pages of this stuff. It simply isn’t possible. And that, of course, is the idea. This is the Mushroom-Growers’ Management Method writ large: keep them in the dark and feed them plenty of sh*t.

What these ramblings conceal is the remarkably rapid rate at which dozens - no, hundreds - of new bureaucracies are being created as The Process grinds on. As anyone at the Playboy Casino will tell you, “somebody gotta pay for all those lights.” And that somebody is you, gentle taxpayer. No one has yet managed to discover just how much these hundreds of new supranational climate-change bureaucracies are costing us. That is an international state secret - until Wikileaks gets hold of the figures, of course.

Follow the Cancun carnival here.

AFTER nearly two weeks of snow and sub zero temperatures rivaling those of Siberia, the old joke about global warming being a good thing has had a new lease of life. So what has happened to doom-laden predictions of the world heating up as glaciers melt?

FIRST the good news. These bitter winters aren’t going to last forever. The bad news is that they will go on for the next 30 years as we have entered a mini ice age.

So says author Gavin Cooke in his book Frozen Britain. He began writing it in 2008 and it was published last year when experts were scratching their heads at the cause of the bitter winter of 2009/10 which brought England to a standstill. Some said it was a one-off event, with experts predicting snowfall becoming increasingly rare.

Now, 12 months on, the current sub zero spell makes last year look just a bit chilly. Just like kids enjoying ‘snow days’ off school, Gavin ought to be delighted with the cold snap. After all, he can justifiably say ‘I told you so. But he’s as glum as the rest of us.

“I’m getting sick of it myself,” he said.

When Gavin, 48, of Monkseaton, North Tyneside, began writing the book the acclaimed documentary ‘An Inconvenient Truth’ by former US Vice President Al Gore about global warming, was still fresh in the memory. It detailed how carbon emissions were contributing towards the melting of the polar ice caps causing the world to heat up.

Like Gore, Gavin’s interest in climate change went back to college when he studied energy and environment at what was then Newcastle Polytechnic.

He said: “The more I’ve looked into it the more fascinating it has become.”

He is quick to admit that he hasn’t got the scientific background of those who have spent a lifetime studying climate change. What he has brought to the table is his enthusiasm for the subject, his tracking of the arguments and a desire to make sense of a blizzard of information, so to speak.

To simplify, the basis of his theory seems to be sunspot activity, or rather the lack of it. Sunspots are dark, cooler patches on the sun’s surface that come and go in cycles.

They were absent in the 17th century - a period called the “Maunder Minimum” named after the scientist, Edward Maunder, who spotted it. Crucially, it has been observed that the periods when the sun’s activity is high and low are related to warm and cool climatic periods. The weak sun in the 17th century coincided with the so-called Little Ice Age. The Sun took a dip between 1790 and 1830 and the earth also cooled a little. It was weak during the cold Iron Age, and active during the warm Bronze Age.

Throughout the 20th century the sun was unusually active, peaking in the 1950s and the late 1980s. Recently sunspot activity has all but disappeared.

Gavin said: “It is the sun’s energy which keeps the earth warm and the amount of energy the earth receives isn’t always the same. I’ve looked at the evidence for global warming and while I understand and agree with a lot of it, there has been a lot missed out. A major factor is the activity of the sun.”

There is also solar wind - streams of particles from the sun - which are at their weakest since records began. In addition, the Sun’s magnetic axis is tilted at an unusual degree. This is not just a scientific curiosity. It could affect everyone on earth and force what for many is unthinkable - a reappraisal of the science behind global warming.

It was thought that carbon dioxide emissions rather than the sun was the bigger effect on climate change. Now a major re-think is taking place.

The upshot is that Gavin is not alone in predicting we face another 30 frozen years, each getting progressively colder than the last.

Particularly hard hit will be Britain and Northern Europe and it is only after the 30-year period that the effects of man-made global warming will kick in. He said: “When I was writing this it was new. To be honest I was kind of winging it, piecing it together. But recently there has been a sea change among some pretty significant figures.”

Glascow Scotland - the best way to travel this year once again

They include renowned international climatologist Mike Lockwood of the University of Reading. In 2007 he said the cyclical change in the Sun’s energy was not responsible for climate change. In April this year, writing in the New Scientist Magazine, he did a U-turn and said it was. After a study, he and his team concluded that recent cold British winters have coincided neatly with the biggest fall off in the sun’s activity for a century, contradicting the accepted view that carbon dioxide emissions and other greenhouse gases are likely to warm our climate.

Gavin laughed: “Looking at the weather outside, sometimes I really wish I was wrong. But we had better get used to it.”

Frozen Britain: How the Big Freeze of 2010 is the Beginning of Britain’s New Mini Ice Age by Gavin Cooke is published by John Blake Publishing Ltd and is out now priced at 7.99 pounds. Also available on Amazon. See post here.

In Cancun, the activists have traded their sackcloth and ashes for sun-wear and tropical breezes

This global-warming/climate change stuff is a great racket. Over in England right now, they’re locked in the jaws of a very early freeze-up. The roads are iced, the plows overworked, and people are angry. But there’s a precious subset of the English population that are not enduring the frigid and premature torments of a northern winter. They’re the climate-change activists, bureaucrats, politicians, puppeteers and NGOs - the class of professional alarmists who’ve been banging on about global warming for close on two decades now. This bunch has exempted itself from the rigors of English November, traded their sackcloth and ashes for sun-wear and tropical breezes.

They’re toasting their pasty, righteous, caterwauling epidermi on the golden hot sands of Cancun, Mexico, flopped out amid the bikinis and barbeques while they attempt to spell out a future of rationing and want for all the rest of us. Flown there on taxpayer or foundation money, meeting up with all their buddies from the bust that was Copenhagen, the grim, grey priesthood of “sustainable” living are convening in one of the great sybaritic strips of the entire Western world. The monks are in the cathouse.

But hey, if you’re going to do Armageddon - do it in Cancun. The apocalypse at the all-you-can-eat buffet. Parasailing to Armageddon.

Does not one of the great minds decoding next century’s weather see the brain-splitting contradiction of holding a conference warning of the imminent threat of global warming in a venue that mainly exists because people fly there to get warmer? That’s right, people spend money to fly to Cancun mainly because it’s warmer there than where they live. In essence, Cancun is what the global warming crowd are, otherwise, warning us about.

Perhaps at some level of instinct they do know. Perhaps they know that this show of theirs is on its last legs, the jig is up, the great game is over. After the unsuccessful 2009 Copenhagen conference, they had to have realized that even Al Gore and all Al Gore’s grim little men would never be able to put the whole rickety, tendentious machine back together again. After Copenhagen, and especially after Climategate, even the true believers must have lost heart. Witness this year’s confabulation. Notice who’s not there?

Last year, even the Golden One, Barack Obama, swept dramatically into Denmark. It was the venue for all the A-list politicians. Prime ministers and presidents were everywhere. This year, the world’s leaders have stayed away. Even the press, whose Cancun presence is down considerably compared to Copenhagen, smells the decay of a cause.

Some countries have made it clear that they no longer are even pretending to play the global-warming abatement game. “Japan will not inscribe its target under the Kyoto protocol on any conditions or under any circumstances,” declared Jun Arima, deputy director-general for environmental affairs at Japan’s Ministry of Economy, Trade and Industry. Given that his was the country where the Kyoto Protocol was signed, it’s a powerful blow to the Gore-ish forces. Perhaps Japan will get one of those cute Fossil of the Day Awards that Canada so excels at collecting.

Could this be the last global warming conference? It’s possible. The environmentalists and the activists have had a tin ear and a surplus of righteousness from the beginning. But there’s something extravagantly out of key, even for them, in holding their great “Save the Planet” revival at Cancun - up to now famous for Spring Break and as a hangout for louche Hollywood types and cleavage researchers. It signals they’ve lost the will to pretend. And with Japan having walked away from the whole idea of Kyoto, it’s hard to see how they’ll work up the steam for another holiday next year.

Rex Murphy offers commentary weekly on CBC TV’s The National, and is host of CBC Radio’s Cross Country Checkup.

See post here.

Average temperatures or temperature ranges are often used as a simple proxy for climate. In combination with some description of rainfall, they encapsulate the essentials: in the Mediterranean it is typically hot and dry in summer and cooler and wetter in winter, and a continental climate is hot and dry in summer and cold with snow in winter, for example. But quantifying climate more precisely is fraught with difficulty.

Records kept over the years give us historical figures to make comparisons between average temperatures then and now. This sounds simple, but the very concept of an average temperature has no simple definition. First, we have to realise that temperature is what is known as an intensive property of matter. This simply means that it does not depend on the nature or size of the material for which it is measured.

So, for example, air and a body of water may have the same measured temperature at a particular moment, but their behaviour is very different. Air has a low thermal capacity (it take little heat to change its temperature), while water has a high thermal capacity and its temperature changes relatively slowly. In the present long cold spell in western Europe, ponds and lakes need a period of consistently sub-zero temperatures before they begin to freeze. Equally, as air temperatures rise, the ice may take many days to melt. A given volume of water has a very different thermal energy content than the same volume of water. This can be easily quantified and, in contrast to temperature, is an extensive property.

When trying to average temperatures, the first obvious rule is that the measurements must all be of the same material: you cannot average air and water temperatures, for example, and get a meaningful answer. This in itself is pretty obvious and, in discussing climate change, air and water temperatures are considered separately. However, the difficulties with averaging do not stop there.

Even if temperatures are measured under carefully controlled conditions as expected for official records, they will fluctuate quite rapidly depending on wind direction and strength, cloud cover, time of day etc. The convention is to measure a maximum and minimum shade temperature each day. These readings can then be used to provide average maxima and minima per month or year, or combined to give an overall ‘average temperature’. And the figures for individual stations can themselves be combined to give national, regional and global averages.

These figures tell us something, of course, but the desire to quantify also obscures the detail. Say, for example, that place X has an average maximum temperature of +15C and an average minimum of +5 and place Y registers +25 and -5. Both have an overall average of +10, but the actual climate experienced would be quite different. In a similar way, measured air temperatures in the shade bear little relationship to the apparent temperature in the sun. Although the measured shade air temperature might be the same whether or not the sun is shining, the effect on the Earth’s surface of the sunlight is significant and, once the ground has been warmed, it will release its heat at night to keep the air somewhat warmer, at least temporarily.

Simple averaging can be deceptive in other ways as well. Depending on the weather conditions or time of year, either the maximum or minimum temperature might be more typical of the day as a whole, yet both are implicitly given equal weight. Nevertheless, it is arguable that such issues are not important when comparing time series of measured temperatures. For example, the Central England Temperature record (CET) is the longest continual record available, with monthly means being recorded from 1659 and daily means logged from 1722. Looking at this it is easy to see the recorded range and note that temperatures do indeed appear to have been higher in the latter part of the 20th Century, although they have dipped again since 2000. It is the changes which are significant rather than the absolute values, provided that all measurements are strictly comparable.

This, of course, introduces yet another concern. The same instruments would not have been used in the 17th Century as 300 years later and, with the best will in the world, it is difficult to guarantee that no artefacts have been introduced. Equally, it is hardly conceivable that the surroundings of the measuring stations will be unchanged over this period (although hopefully none of the weather stations is now in an urban area, on tarmac or near heat sources as some have been found to be in other countries).

A final problem to bring up with averages is that, to avoid giving a misleading picture, data should be taken from stations spread evenly over the Earth’s surface. This is certainly not the case. In particular, there are large areas of the Arctic and Antarctic with no data being collected. The same is true for the open oceans, where collecting surface water temperatures reliably is enough of a challenge, without trying to measure air temperatures.

What we are left with then is an incomplete record of imperfect data, from which conclusions about climate change are drawn. This is the basis of the ‘global warming’ message. But actually the concept of global average temperature is again a little misleading, since the summary of the IPCC Fourth Assessment Report shows that the warming pattern is regional rather than global. Warming over the 20th Century was recorded on all continents apart from Antarctica, but was considerably greater in the northern than the southern hemisphere. Given the greater proportion of ocean in the south, this is not surprising.

But global averages are still the main measure and this is the time of year when preliminary conclusions are drawn about the current year, as the annual meeting of the UN Convention on Climate Change takes place. So far, the message being put out by the World Meteorological Organization is that 2010 is likely to be among the warmest three on record. Based on the temperature record, this is doubtless correct, but how meaningful is this?

The WMO points towards record high temperatures in Russia, China and Greenland to support its case. Meanwhile anyone mentioning record lows and pointing out that new records are set nearly every day somewhere in the world is told that this means nothing. In practical terms, life has to go on and adapt to whatever climatic conditions turn out to be. Measuring temperatures remains a useful thing to do, but we must be careful not to read too much into the average figures. And we should never forget that, whatever the temperature is, we still have only a hazy idea about what controls it. Read more here.

Icecap Note: See here how even James Hansen agrees.