Last update   -  1635 GMT,   15th Aug 2008   


The 1841 sea level benchmark (centre) on the `Isle of the Dead', Tasmania.  According to Antarctic explorer, Capt. Sir James Clark Ross, it marked mean sea level in 1841
.  Photo taken at low tide 20 Jan 2004.
Mark is 50 cm across; tidal range is less than a metre. © John L. Daly.
If the benchmark is difficult to see, try these.

A Lukewarm View of
 Global Warming

This site was founded by
John L. Daly
(click his name for information about John)

A selection of photos of Tasmania and from John Daly's 2002 trip to the U.S.A.
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      Recently updated items     

Updated Satellite Temps
(15 Aug 08)

Updated El-Nino/Southern Oscillation data
(15 Aug 08)

Time of Observation Bias
(14 Nov 05)

When using a pair of min/max thermometers for daily temperature observations, the time of day at which the readings for the previous 24 hours are observed, and the thermometers are reset, will often cause a time of observation bias (TOB). If readings are taken near the times of daily highs, or daily lows, those highs, and lows, often affect the readings of two days.

For those who may have some interest in such phenomena, an introductory review is available here.

Visiting Warwick Hughes
(23 Oct 05)

Let me call your attention to a recent addition there.
(1 Jun 05)

In case you have not followed the links, Steve McIntyre has many interesting posts at

Climate Catastrophe - Cancelled
(19 Apr 05)

OTTAWA: On April 13 the University of Calgary, in cooperation with the Friends of Science Society, released a video entitled: Climate Catastrophe Cancelled: What you're not being told about the science of climate change.

The 25 minute video is available as a set of five .wmv files at the Friends of Science Society website.

While presented in a Canadian context, the issues are not limited to Canada, and at least several of the participants will be familiar to regular visitors of this website from around the world.

Hockey Stick Saga Developments
(31 Jan 05)

It seems that as more researchers examine the McIntyre and McKitrick critique of the Mann et al "hockey stick", their critique gains increased support. Several recent developments are described at their websites.

You might start here and follow pertinent links for additional details.

A Quiet Anniversary
(1 Oct 04)

Have you adjusted your temperature data lately?

Historical temperature records usually include effects of various changes in the locations, and kinds of, thermometers, and of observer procedures, including times of day of observations, all of which can have "non-climatic" effects on the temperatures that get recorded.

Such "non-climatic" effects on recorded temperatures get considerable attention by researchers, and various kinds of methods have been devised to adjust the "raw" data so as to compensate for those effects.

Many people may recognize the name John Christy due to his work on calculating atmospheric temperatures from microwave data collected by NOAA satellites. He is also the state climatologist of the state of Alabama, USA, and when he attempted to answer the question "when was the hottest summer in north central Alabama?", his attempt required a large amount of research. It is discussed in considerable detail in a paper in the Bulletin of the American Meteorological Society linked from the abstract (at that page, click on the "print version" link for a PDF of the paper), and it included attempts to compensate for such non-climatic effects.

For a data set called the United States Historical Climatology Network (USHCN), researchers compiled monthly data of about 1200 weather observation stations. They also compiled data about changes of equipment, location, observer, and time of day of observation. Summaries of such changes are included in a station history file, and various adjustments to "raw" temperature data are based on data about such changes.

Other collections of temperature data, such as the Global Historical Climatology Network have other methods of attempting to compensate for such "non-climatic" effects, but for the stations in the USHCN, use the USHCN adjustments. And recently, the NASA Goddard Institute for Space Studies (GISS) started using USHCN adjustments for temperature data from those stations instead of using the methods used by GISS for temperature data from other stations.

One may get the impression that the USHCN adjustments are regarded as relatively good adjustments, even by at least some other researchers who use other methods for temperature data from other stations.

That may lead one to wonder how good are the adjustments made by those people for temperature data from all of the other stations in the GHCN/GISS collections.

Oh yes, the title of this article alludes to an anniversary. October 1, 2004, is the tenth anniversary of the most recent update to the USHCN station history file.

About Nature
(14 Sep 04)

A magazine named Nature is said to be a "journal of science".

Its mission statement is said to be

First, to serve scientists through prompt publication of significant advances in any branch of science, and to provide a forum for the reporting and discussion of news and issues concerning science. Second, to ensure that the results of science are rapidly disseminated to the public throughout the world, in a fashion that conveys their significance for knowledge, culture and daily life.
Perhaps you may get some idea of whether that statement means what it says by visiting this webpage where, under "Notes and Updates", you will find:
UPDATE: September 13 2004: Following our publication last year and the response by Mann et al., we planned a 3-part reply. The first part concerned the provenance of the data used for our analysis and was released in November 2003. The second part would itemize many additional lacunae and inaccuracies in MBH98 descriptions of data and methodology identified through examination of Mann's FTP site, and the third part would show that two undisclosed and questionable methodological decisions in MBH98 accounted for virtually all of the difference between our results and MBH98. These projects went through a lengthy review process with Nature, with interesting results. We can now provide a public update on this process. Because of its length the new material is on A NEW PAGE HERE and begins with the latter item first.
Many of the "interesting results" can be appreciated whether, or not, you have any degrees in statistics. If you have an interest in the IPCC's favorite "Hockey Stick", and the McIntyre and McKitrick critique thereof, you may find M&M's latest update very interesting.

CO2 Measurement Problems
(25 Aug 04)

When reading about extraction and analysis of atmospheric gases from ice cores, you may notice some things that seem rather odd. One favorite such oddity is a statement in the file Historical carbon dioxide record from the Vostok ice core:

Using semiempirical models of densification applied to past Vostok climate conditions, Barnola et al. (1991) reported that the age difference between air and ice may be ~6000 years during the coldest periods instead of ~4000 years, as previously assumed.
Whether 4000 or 6000, neither number would seem to inspire much confidence that the results of the analyses are likely to be very accurate.

So, when recently visiting Warwick Hughes' website and noticing, among several other interesting items, a brief description by Zbigniew Jaworowski of accuracy problems of CO2 measurements in ice cores, it seemed to be especially interesting. So interesting that there is now a copy of it right here. Whether here, or there, I trust that you also will find it very interesting.

Hot and Cold Summers
(23 Aug 04)

A paper titled "European seasonal and annual temperature variability, trends, and extremes since 1500" was published in the issue dated March 5, 2004, of the AAAS magazine named Science. It seems that the authors concluded that the summer of 2003 was the hottest summer in Europe since 1500.

It also seems than Hans Erren does not share that conclusion, and in an article at A debatable European summer temperature since 1500 he suggests that the summer of 1540 rivals the summer of 2003 in the category of hot European summers.

Among the points of contention are the accuracy of tree ring, and other, proxies for temperatures, as well as the validity of extrapolation of small geographic area information to large geographic areas. You may find the discussion interesting.

Let me mention an aspect that particularly caught my attention. In the comparison of the Luterbacher et al. graph with a graph based on the Pfister index, the Pfister index indicates that the notorious summer of 1816 was particularly cold, which seems quite plausible to me; the Luterbacher et al. graph does not, which seems not quite so plausible to me.

Was there a tree ring problem, an extrapolation problem, or what?

Mauna Loa CO2 Measurements Updated
(5 Aug 04)

In March of this year a widely reported story about CO2 measurements at Mauna Loa was discussed in CO2 Report Makes the Rounds. Since then, the data on which the report presumably was based have been posted at CDIAC.

Here is a graphic summary of annual averages of the CO2 measurements at Mauna Loa since 1960, including the data added for 2003.

Keeping in mind that the unit of measure is ppmv (parts per million by volume), it is clear that CO2 is a very small portion of the atmosphere. Among the so called greenhouse gases, it is a very distant second to H2O. And yet, some people portray CO2 as if it had almost mythical powers of dominating climate around the globe. A glance at some other measurements may help clarify the picture somewhat.

(3 month averages of lower troposphere temperature variances and inverted SOI)

While the atmospheric parts per million of CO2 have continually increased during recent decades, atmospheric temperatures have risen, and fallen, uninfluenced by any notions that some people may have about the powers of CO2. Atmospheric temperatures respond to realities, not myths.

As for the amount of the increase of atmospheric CO2 from 2002 to 2003, it was approximately two and one half parts per million, 2.54/1000000.00 to be more precise. Here is a graphic summary of the annual increases since 1960:

As he did in March, Miceal O'Ronain has provided, in both tabular , and graphical , forms, nice compilations of year to year differences of monthly, and annual, averages of Mauna Loa CO2 measurements.

Solar Activity and Terrestrial Climate
(28 July 04) updated (30 July 04)

On July 6, 2004, a BBC article, headlined Sunspots reaching 1000-year high, caught the attention of a number of readers. Related articles soon appeared in other publications, for example: Suspot activity hits 1000-year high at, The truth about global warming - it's the Sun that's to blame at the London Telegraph, and Hotter-burning sun warming the planet at the Washington Times.

It seems that at a conference of astronomers in Hamburg, Germany, Sami Solanki and colleagues presented a discussion of possible correlations between solar variability and terrestrial climate. The recent articles provide some clues to the content of the presentation, but a slightly closer look may be of interest.

Interestingly enough, the principal paper on which the presentation was based was published last year, and briefly discussed here by John Daly at Evidence for an Unusually Active Sun. An abstract of the paper is available at Millennium-Scale Sunspot Number Reconstruction: Evidence for an Unusually Active Sun since the 1940s. The paper is available in PDF form at I.G. Usoskin, S. Solanki, M. Schuessler, K. Mursula, K. Alanko, A millennium scale sunspot number reconstruction: Evidence for an unusually active sun since the 1940's, Phys. Rev. Lett., 91(21), 211101, 2003. (Hereinafter, Usoskin et al. 2003)

Of several closely related papers I will mention I.G.Usoskin, K. Mursula, S. Solanki, M. Schuessler, and K. Alanko, Reconstruction of solar activity for the last millennium using 10Be data, Astron. Astrophys., 413, 745-751, 2004.. (Hereinafter, Usoskin et al. 2004)

Using records of 10Be (Beryllium 10) concentration in polar ice, and some physical models for processes connecting 10Be concentration with sunspot numbers, the authors attempt to reconstruct average sunspot numbers for the period from the year 850 to the present. Their reconstruction indicates that the period of high solar activity during the last 60 years is unique throughout the past 1150 years.

The 10Be records they use include annual data from Greenland for the years 1424 to 1985, and eight year sampled data from Antarctica for the years 850 to 1900. They supplement those data with some 14C (Carbon 14) data, apparently for most of the period of the study, and with group sunspot numbers (GSN) from 1610 on. While their methodology has its problems, they claim it results in a better correlation of 11 year smoothed "reconstructed" sunspot numbers with historical GSN than a statistical regression would do, and they summarize their results in a graph that includes indicators of MM: Medieval maximum, Om: Oort Minimum, Wm: Wolf minimum, Sm: Spörer minimum, Mm: Maunder minimum, and Dm: Dalton minimum. It also includes estimated corrections of their calculated sunspot numbers in the solid red and green lines.

Figure 2 from Usoskin et al. 2003

You can readily notice various differences between their Greenland and Antarctic results, as well as between either of those and GSN, particularly during the Maunder minimum. These, and some other difficulties, are briefly discussed in Usoskin et al. 2003.

Of the presentation in Hamburg there is available a file of slides, Solar Activity over the last 1150 years: does it correlate with Climate?. Among those slides is the above graph, as well as several other graphs not included in Usoskin et al. 2003. Among the latter are two on a slide labelled: Comparison: Sunspot number & Climate.

The next slide from the presentation offers

I would guess that the trend that correlates at 0.7-0.8 level is somehow related to the very smooth lines that run through each of those two graphs, including the sunspot lines that continue climbing right through the Maunder minimum. If their models cannot get more realistic about a phenomenon such as the Maunder minimum, they would seem to need much more work before asking people to take their climate correlations seriously. I suspect that one can find a variety of statistical trends that appear to correlate incidental aspects of phenomena. As displayed in the presentation, the proffered trend seems to me to be a distraction from identifying correlations based on physical causation.

A subsequent slide of the presentation asserts SN runs ahead of climate by 10 years (SN presumably being their calculated sunspot numbers). I can imagine various lead times between sunspot numbers and various climatic effects, but I cannot see a 10 year lead time in either of those two graphs. (If you can, please let me know.)

While Usoskin et al. 2003 and related papers, including their difficulties, seem to me to be quite interesting, it also seems to me that the attempt in the presentation to portray a correlation with either version of the hockey stick, much less with both versions, was not conducive to resolving any of the difficulties.

Some incidental comments: Usoskin et al. 2003, and the presentation, emphasize the very much higher sunspot numbers in recent years than in earlier years, even within the historical series of group sunspot numbers. I estimate that the 11 year smoothed GSN of 1959 is about 57 per cent higher than that of 1790, which by my calculations was the highest before 1935. However, using Wolf sunspot numbers (WSN), the 11 year smoothed sunspot number for 1959 seems to be only about 20 per cent higher than that of 1790. Still higher, but not as strikingly so. The next two graphs present annual, and 11 year smoothed, comparisons between numbers based on each of the systems.

(Data for these two graphs are from: GSN and WSN ).

I am not aware of the relative merits of the two numbering systems. One obvious advantage of GSN is that they extend back to 1610, while WSN extend back only to about 1700, and some might suggest only to about 1750.

Update added 30 July 2004

A recent UPI article, Climate: The Vanishing Solar Factor, has been added to the mix. I will comment briefly on just a couple of parts of it.
In order for the sun to force the climate to the little ice age observed during the Maunder Minimum, the change in the solar constant had to be about twice what has been observed during modern, zero-sunspot periods.
1. Modern zero-sunspot periods have been very brief. The most recent calendar month with a zero WSN was June 1913; the most recent calendar year with a zero WSN was 1810. A zero sunspot day, or week, may not tell us much about what the so-called solar constant would do during a zero sunspot year, or a zero sunspot decade.

2. The statement implies an assumption that variations of solar wind and the magnetic heliosphere, and variations of the flux of cosmic rays, have no climatic effects, but without addressing research results indicating that they do. Raimund Muscheler probably could direct the author of the article to some of that research.

In the 2002 Harold Jeffreys Lecture to the Royal Astronomical Society in London, Solanki said: After 1980, however, the Earth's temperature exhibits a remarkably steep rise, while the sun's irradiance displays at the most a weak secular trend. Hence the sun cannot be the dominant source of this latest temperature increase, with man-made greenhouse gases being the likely dominant alternative.
1. That statement suggests that Solanki had not yet read Usoskin et al. 2003, which he co-authored. :-) Again, solar irradiance is not the only solar variable.

2. If the "latest temperature increase" refers to a globally averaged surface temperature increase which allegedly exceeds lower free troposphere temperature changes, then it refutes, rather than supports, notions of greehouse gases being a plausible, much less a likely dominant, alternative.

Corrigenda Anyone?
(2 July 04)

Steven McIntyre and Ross McKitrick have posted an update about the process of resolving issues raised by their assertions of errors in the Mann et al 1998 paper of Hockey Stick fame:

The Corrigendum in Nature today (July 1, 2004) by Professors Mann, Bradley and Hughes is a clear admission that the disclosure of data and methods behind MBH98 was materially inaccurate. The text acknowledges extensive errors in the description of the data set. Even more important is the new online Supplementary Information (SI) site, which reveals for the first time that key steps in the computations behind MBH98 were left out of (and indeed conflict with) the description of methods in the original paper.
There are additional comments at Ross McKitrick's website (scroll down a page to the update).

Those who missed it may find John Daly's related article, "Broken Hockey Stick" of interest.


For previous
"Stop Press!" items,
click above on
the Tasmanian Devil

Links to Selected Articles

Under construction: a
list of articles at various websites which may be of interest. At this time, a very short list.
Last updated: (14 Apr 04)


Recent Guest Papers

New ENSO Forecasts Based on Solar Model
by Dr Theodor Landscheidt (Germany)  (22 Dec 2003). The latest forecast from Dr Landscheidt's solar model for predicting ENSO events.
The next El Niño should emerge around July 2006 and last at least until May 2007, with a probability of 80%.

Cyclonic Storms Over Western Europe by   Max Beran (Britain)  (15 Dec 03).  Max Beran analyses claims by the Hadley Centre that a significant trend in UK storminess over the past half-century or so had occurred.  He finds that a faulty treatment of the North Atlantic Oscillation resulted in the claimed effect being a statistical artefact, not actually real.

Variations in CO2 Growth Rate Associated with Solar Activity  by Dr Theodor Landscheidt (Germany) (21 Sept 03).  Solar activity and solar motion variations are found to explain much of the variability of CO2 growth over the last several decades.  The average annual increase over the last 10 years was 1.66 ppmv/yr, which is less than half that assumed by climate models. 

  Weather Station(s)
of the Week

This week - (click the name)

Colombia Stations

This week' stations are Bogota, the capital of Colombia and three other stations, Neiva, Calipuerto, and Las Gaviotas.

There would appear to be little or no hope that `climate change' might impact adversely on the illicit coca crop.  Very little change is evident, one station  showing cooling, Bogota showing slight warming  (most likely the result of urban heating), and the other two with neutral trends.

(Click below for other, mostly rural,  weather station records from around the world.)

Also in ...  Español

Latest Weather & Climate Information

Latest Satellite Image of Australia
      from James Cook University. Time is in GMT

 Latest MSL Synoptic Chart of Australia
      from Australian Bureau of Meteorology. Time is in GMT

Daily Global Sea Surface Temperature
      from University of Wisconsin-Madison, USA

Sea Surface Temperatures
Sea Surface Temperature variances from average ;   from FNMOC, USN, USA
(links updated Dec 8,2004)

 Monthly Sunspot Data (Cycle 23) 
       from data published by IPS, Australia

Latest U.S. Temperatures (time in GMT, temp. in ºF)

 Global Mean Sea Level - See critique of TOPEX-Poseidon

Latest Arctic Sea Ice and Snow Cover
     from University of Illinois

Northern Hemisphere Sea Ice
Southern Hemisphere Sea Ice

   from FNMOC, USN, USA
(links updated Dec 8, 2004)

El Niño/La Niña 
Southern Oscillation

Click on the image below for the latest on the
El Niño/La Niña Southern Oscillation


For recent "news" media stories, some climate related, others not, a web site which may be of interest is

Special Reports on Major Climate Issues

The Peer Review System: Is Climate Science Politically Corrupt? - Testing the peer review process, and finding it wanting

(John L Daly's last paper)
(Published 22 Feb 04)
(Also of interest: a previously published, but quite apropos, John Brignell article)

Sea Level at Hobart, Tasmania: A Failure to Authenticate - The authors of the `sea level rise at Port Arthur' scenario are shown to have failed to authenticate a vital claim they made about sea levels at Hobart, Tasmania (11 Jun 03)

Tasmanian Sea Levels:  The Isle of the Dead Revisited - A detailed report on the 160-year-old sea level benchmark at Port Arthur, Tasmania, which some scientists think is evidence of sea level rise, but which actually shows no such thing  (2 Feb 03)

Quality Control - CRU Style (15 Aug 2001).  
The full story on CRU's lack of quality control. 

Suzuki's Home Town - London, Ontario, Canada  - David Suzuki says winter comes later now in his boyhood home town.  But the weather records from there and nearby show his claim is false.  (26 Apr 03)

Greens Sue U.S. Government (31 Aug 02)  Greenpeace and Friends of the Earth have mounted a lawsuit against the US government.  But why has the City of Boulder, Colorado, joined them?  Find out here.

"Australia ratifies the Kyoto Protocol - and implements it how, exactly?" (21 Aug 02) - A discussion on the economic impact Kyoto would have on Australia.

Badwater (19 Jul 02).  A world record in the making...

TOPEX-Poseidon Radar Altimetry:  Averaging the Averages  (5 Dec 2001).  Just how accurate is sea level monitoring from satellites?

`Making' the News:  The Sunday Times and British Climate (20 Nov 2001).  How the London Sunday Times has distorted climatic data for Britain without so much as a murmur from the originators of that data. 

The Nenana Ice Classic: Betting on Warming  
(28 Oct 2001).  Alaskans have been betting on the date and time of river ice breakup at Nenana every Spring. Now the Greenhouse Industry is in on the act, with some sloppy science in `Science'.

A Day in the Life of the Scientific Republic of Australia -
A dark fable for Christmas  (Dec 2003)

The `Hockey Stick': A New Low in Climate Science
(12 Nov 2000)  
The new dogma by both the IPCC and US National Assessment is that the Medieval Warm Period and the Little Ice Age during the last millennium never happened. Their claim is false and politically inspired.

A Clap of Thunder (12 May 2001).   The saga of the Barrow Thunderstorm of 19th June 2000 in Alaska.

The Return of `Moby Dick' (17 April 2001)  Two papers in Science about the deep oceans which make lots of questionable assumptions. 

A Smoking Pea-Shooter (19 March 2001)  Human influence on the  greenhouse effect has now been measured in a British study of two sets of satellite data 27 years apart. This report  reveals some surprising facts about the study not reported in the media. 

The Top of the World: Is the North Pole Turning to Water?
(2 Feb 2001)   Water at the North Pole was big news in August 2000. Was it just another media scare story, or is the Arctic sea ice really disappearing?  This report details the whole issue of Arctic sea ice.
Also -  See this BBC report on Arctic Sea Ice

Testing the Waters: A Report on Sea Levels   (July 2000)
Has global sea level risen 10 - 25 cm during the 20th century as claimed by the IPCC? This report presents evidence to show that the claim is false and based purely on modelling.

The Surface Record: Global Mean Temperature and How it is Determined at Surface Level   (June 2000)   An argument for an independent review of the `surface record'. The satellites were reviewed, so why has the `surface record' escaped independent examination?

Sea Levels:  The `Isle of the Dead'

"Is this the picture that takes the heat out of global warming?" - asks the BBC
Photo 29th Aug. 1999, 1.04 pm, AEST (around mean tide)
  © John L. Daly

Melbourne Herald-Sun on the `Isle of the Dead'

Recently, the world's media was abuzz with reports from Tasmania that a 160-year-old tidal mark had been found in south-eastern Tasmania, and that scientists had concluded that it showed evidence of `dramatic' sea level rise during the 20th century.

The media blitz which preceded a public lecture given in Hobart by the scientists involved, spoke volumes about the wider political agenda at stake.

Now the full details about exactly what these scientists think they have found - and more importantly the errors they have made - and the fragile statistical base upon which their `sea level rise' scenario rests, is all detailed in this report on Tasmanian Sea Levels.

Click here for Part 1      Click here for Part 2

Testing the Waters: A Report on Sea Levels

In April 2003, three of the scientists involved in the earlier claims that sea level had risen at the `Isle of the Dead' published a new paper in Geophysical Research Letters in which they sought to reinforce their claims with new information about tides and sea level at nearby Hobart, Tasmania, information which had not been presented by them in their earlier, more detailed, paper of November 2002.

The key reference they provided for this new information proved to be of no value in supporting their claims.   But another, much more significant, problem in their paper was also discovered.  Full details here -

Sea Level at Hobart, Tasmania:  A Failure to Authenticate

Tuvalu - Pacific Islands Crying Wolf

The Government of Tuvalu, egged on by GreenPeace, is the most strident of small Pacific island countries, claiming they are being swamped by rising seas caused by global warming.    Predictably, they want `compensation' from the USA and Australia.    But tide data from Funafuti, the capital of Tuvalu, data collected with Australian expertise and equipment, shows their claims to be both alarmist - and false.   (Data from the National Tidal Facility (NTF), Adelaide)

In March 2002, the NTF stated  "The historical record shows no visual evidence of any acceleration in sea level trends."  Instead, they suggested coastline degradation and sinking islets in Funafuti,  were the result of entirely local conditions, not sea level rise.  (AFP story) 

`Global Mean Temperature' - Disputed Data

    The `Surface Record'  

It's not really a record at all, but a statistical composite from station records from all over the world, most of them from towns and cities, and most from countries which do not maintain their stations or records properly.

This record is compiled by the Goddard Institute (GISS) in the US.  It indicates a global warming of +0.8°C. Is it real? Or is it just a statistical product of urban warming skewing the data, and bad site management in non-OECD countries?

The pre-1940 warming is widely regarded to have been caused by the warming sun during the earlier part of the 20th century.

     The U.S. Record    

This is the combined record from hundreds of weather stations in the 48 states of the contiguous USA., the early 1930s being the hottest years of the 20th century. This is completely at variance with the global record shown above. (Both graphs were produced by NASA-GISS)

Urbanisation has been more successfully corrected for in the US than in the rest of the world and the US also has the best maintained network of weather stations in the world. This must therefore be a better representation of the global picture too. The US record also agrees with the satellites (shown below)

    The Satellite Record 1979-2006  

    The newest and best way to determine global temperature is to use satellites to measure the temperature of the lower atmosphere, giving the Earth a uniform global sweep, oceans included, with no cities to create a false warming bias. This second method, used since January 1979, has a published margin of error of +/- 0.05 C/decade, and is clearly the best record we have.  Here are Global Mean Temperature anomalies of the lower atmosphere for the 29-year period January 1979 to July 2008. It shows a very different picture to that of the global `surface record' over the same period.

Global trend per decade = +0.130°C,    (Northern Hemisphere = +0.197°C,     Southern Hemisphere =  +0.063°C. )
July 2008 Global  =  0.048°C,     (Northern Hemisphere =  0.094°C,    Southern Hemisphere = 0.003°C.)

(Caveat: Update 3 Jan 2008 from John Christy and Roy Spencer)

We now have data from AQUA added to the time series beginning with day 221 of 2002. AQUA is a spacecraft with on-board propulsion and thus has stable station-keeping. Thus, AQUA's AMSU will not be subject to diurnal temperature drifts. Upon comparison with NOAA-15's AMSU, we find only minor differences for their 5+ year overlap, with NOAA-15 being slightly warmer near the end of the time series for LT and MT. The error values for NOAA-15 are much smaller than what we indicated (in an earlier update).

At this time we are merging AQUA into the time series while keeping NOAA-15, with its slight, spurious warming, in the mix through the present. There will be some slight month-to-month differences versus the version from last month, but these are very small so we will keep the version numbers as they are since nothing has changed except the merging of AQUA into the time series. We note that 1-11 Dec 2007 are missing in AQUA and are hoping these will be recovered. We do have all daily values from NOAA-15 for December.

The actual data from which the above graph is derived.       Northern & Southern Hemispheres compared.
For further info see the Global Hydrology and Climate Center at the University of Alabama - Huntsville, USA

See The Surface Record: Global Mean Temperature and How it is Determined at Surface Level  by John L. Daly.
An argument for an independent review of the `surface record'. The satellites have been independently reviewed several times, so why has the `surface record' escaped an independent examination in the public interest?

`What the Stations Say'

(See `El Niño and Global Temperature', to see why some years are hot, and some are cool.)

Other Site Contents (Click the section label)

Storm Chasing in Tornado Alley      -    plus movie clip   (2.7 MB download in .mov format)

Climate Change in Antarctica - through the eyes of an 11-year-old reader of this website

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