More on the absurd ACORN adjustment process

September 29, 2015

This is a Letter to the Editor of The Australian I sent recently, but not published.


Dr Jennifer Marohasy (Ideology adds heat to the debate on climate change, 29/9)  claims that sites prone to Urban Heat Island effect, such as Melbourne, have been used to adjust the temperature records at sites such as Cape Otway.

This is indeed absurd, but true.  Of the 104 sites used for climate analysis, 22 have been adjusted at least in part by comparison with sites whose artificially raised temperatures make them unsuitable for use in that same climate analysis.

The Bureau of Meteorology lists eight sites which are not used in climate analysis because their records exhibit Urban Heat Island effects: Townsville, Rockhampton, Sydney, Richmond (NSW), Melbourne, Laverton RAAF, Adelaide, and Hobart.

According to the Bureau’s “ACORN-SAT Station adjustment summary”, seven of these sites are still used as comparison sites when adjusting raw temperatures at other locations.  Adelaide is used at Snowtown and Port Lincoln; Townsville at Cairns, Mackay and Charters Towers; Rockhampton at Townsville, Mackay, Bundaberg and Gayndah; Sydney at Williamtown, Bathurst, Richmond, Nowra, and Moruya Heads; Laverton at Orbost, Sale, Wilson’s Promontory, Melbourne and Cape Otway; Melbourne at Orbost, Sale, Wilson’s Promontory, Laverton, Kerang, and Cape Otway; and Hobart at Launceston, Eddystone Point, Cape Bruny, Grove, and Butlers Gorge.

Richmond (NSW) is apparently the only site not used in the adjustment process.

Greg Hunt’s faith in the credibility of the Bureau of Meteorology is touching, but just as absurd.

Pause Update September 2015

September 11, 2015

UAH v6.0 data for August were released on Wednesday.  Here are updated graphs for various regions showing the furthest back one can go to show a zero or negative trend (less than +0.01C/ 100 years) in lower tropospheric temperatures.  The strongest El Nino since 1997-98 is affecting some regions more than others.


global aug

Due to the strong El Nino, global temperatures are expected to continue to increase until May or June of 2016 (at least until February).  This will shorten the Pause.

Northern Hemisphere:


Southern Hemisphere:

S hemis aug

Tropics (20N – 20S):

tropics aug

Tropical Oceans:

tropic oceans aug

The bulk of solar heating of the Earth occurs in the tropics, which is  mostly ocean, and ENSO events occur here.  Since October 1992, very much before the 1997-98 Super El Nino, there has been no warming at all.

North Polar:

N Pole aug

South Polar:

S Pole aug

Oops!  For the whole of the satellite record, there has been NO warming in the atmosphere above Antarctica.  Remember, one of the “fingerprints” of global warming due to the Enhanced Greenhouse Effect is greater warming towards the Poles.

USA 49 States:

USA aug


aust aug

There has been no warming in the atmosphere above Australia for almost the whole lives of the current cohort of 1st Year Uni students. Just for comparison, the Australian ACORN-SAT surface data show a pause since February 2002- since they were in Preschool.

aust acorn

The Pause continues.

The Carbon Tax We Still Pay

September 7, 2015

Under Prime Minister Julia Gillard a Carbon Tax was introduced into Australia, set at $23 per tonne of CO2 equivalent, with numerous exclusions and a compensation package.  Apparently fulfilling his promise to get rid of the Carbon Tax, Prime Minister Tony Abbott’s coalition government succeeded in repealing it on 17 July 2014.

Unfortunately we still have a myriad of green schemes, solar bonus schemes, and of course our Renewable Energy Target.  How much does this cost us?  The following is based on regional Queensland, but applies Australia wide.

Ergon Energy provides electricity to all of Queensland outside the south-east corner.  With my last bill was included Ergon’s latest pamphlet for residential consumers, Issue #5 of “The Bright Side”.  Half of this issue was devoted to changes to electricity pricing and how it will affect consumers.  Ergon, and the Queensland government, have been claiming that after a couple of years of steep rises, 2015-16 will actually see a small drop in prices.  I read the information with interest, and as well checked with the Queensland Competition Authority (which sets prices).

Ergon summarises the changes to the typical Tariff 11 bill over a full year with this supposedly helpful graphic:

Ergon price changes

You will note that the cost to the average consumer of the solar bonus scheme and the Renewable Energy Target will rise by $23.  So what, you say, the average bill will reduce by $7.  Actually, it’s not so simple.   Ergon gives five scenarios of how it will affect consumers.  The QCA provides more detailed information, with percentages of the total cost.

qca elect prices

This is based on an annual Tariff 11 consumption of 4,053 kWh, which is the average for residential customers. From this, it is possible to calculate exactly the changes and how much of this goes towards solar and RET schemes.  As well, using an estimate of 0.86 Tonnes of CO2 per Megawatt-hour (0.84 – 0.88) for black coal power stations, it is possible to estimate how much CO2 the average consumer is directly responsible for.  Of course, the 0.86 is for the generation of electricity, not consumption, and consumption is about 83% of electricity generated.  This has been incorporated in my estimates.

In 2014-15, the direct additional cost to the average consumer of the solar and RET schemes was $146.63, rising in 2015-16 to $169.63.

This represents a direct additional cost to the consumer of approximately $34.90 per Tonne of CO2 emitted, rising to $40.40.

A direct additional cost imposed through government policy is a tax.  Applied to residential consumers it is a nasty regressive tax, as it applies to all regardless of income or capacity to pay.  The Solar Bonus Scheme portion is particularly cruel, as low income consumers are subsidising those who could afford and took advantage of this scheme, which will keep paying 44c a kWh feed in tariff for original systems until 2028, now reduced to 6.348c for new systems.  This cost the average consumer $106.64 last year, and the $20 extra is an increase of 18.75%.

Not only that, the Joe Hockey argument does not apply.  Poor people who do use less than 3,800 kWh will see an increase in their bill, while those who use more than 3,800 kWh will see a decrease, and proportionately less the more they consume.

This is robbing the poor to pay the rich.  It is set to continue with the proposed increases in the RET, so the poor will be subsidising inefficient green projects well into the future.  A scheme too good to be true certainly is.  Years ago I knew the Solar Bonus Scheme was an unsustainable scam and immoral.  Now, more than ever, both the Solar Bonus Scheme and Renewable Energy Targets should be completely abolished, with compensation for Solar Bonus users limited to initial cost of installation less subsequent feed in revenue.  Poor people have better things to spend their money on.

More Rutherglen Nonsense

August 15, 2015

Jennifer Marohasy had an interesting post this week on further explanations by the Bureau for their weird adjustments at Rutherglen.  I was particularly interested in this graphic, which is Chart 3 on the Bureau’s station adjustment summary for Rutherglen.

rutherglen comp BOM

The Bureau is comparing Rutherglen’s raw minima with the adjusted data from Wagga Wagga, Deniliquin, and Kerang.  Three questions immediately spring to mind:  1. As Dr Marohasy points out, what is the Bureau doing comparing raw with adjusted data?  Of course they’re going to have different trends!  2.  Why is Kerang shown, when Kerang is NOT included as a neighbour station used to adjust Rutherglen?  And 3.  What difference does this make?

Time for a reality check.

This graph compares like with like: raw minima for Rutherglen and the same neighbours.  Note that only Kerang is warming, and Wagga Wagga is flat, but Deniliquin and Rutherglen are cooling.

rutherglen comp raw

This graph again compares like with like, the same stations but with adjusted data.

 rutherglen comp adjusted

You might think that this shows Rutherglen is now homogenised with the others correctly.  However, when we examine the differences in anomalies from the 1961-1990 means between Rutherglen and the others, we get this:

rutherglen comp differences ADJ

They still got it wrong!  The trend in differences should be close to zero.   Rutherglen’s adjusted record is warming too fast (+0.5C per 100 years) relative to the three neighbours used by the BOM in their explanation.

And note that since 1974, Rutherglen’s minima have been cooling relative to the others.  Perhaps that cooling they corrected for was real after all?

Even if Rutherglen needs to be adjusted; even if these three sites are adjusted correctly; even if Kerang is one of the stations used by the Bureau to adjust Rutherglen- the adjustments at Rutherglen are over cooked.

The “scientists” in charge of the climate change department in the Bureau deserve all the ridicule they get.

More than that- they are not to be trusted with the nation’s climate history.  We don’t trust their data; we don’t trust their methods; we don’t trust their results; and we don’t trust their motives.

Global Warming in Antarctica

August 10, 2015

Global Warming is supposed to have greater effect in polar regions, but for some time the apparent refusal of the South Polar region to comply has been of some interest.  Sea ice area increase can be explained away by various mechanisms, but actual temperatures are more difficult to explain.

Using UAH V6.0 data, here is the graph of the Temperature of the Lower Troposphere (TLT) for the South Polar Region, below 60 degrees South, since satellite records began in December 1978.


For as long as we have records, Antarctica has not warmed at all.  The trend is -0.04 degrees Celsius (+/- 0.1C) per 100 years.  Zero trend, (or slightly cooling if you want to annoy your Global Warming Enthusiast colleagues).


Heatwaves: From One Extreme To Another

August 8, 2015

When Is A Heatwave Not A Heatwave?

When the Bureau of Meteorology defines it out of existence.

In his reply to me on behalf of Dr Vertessy, Bob Baldwin wrote:

“The Bureau has adopted a particular operational heatwave definition motivated by human health considerations, defined as a period of at least three days where the combined effect of high temperatures and excess heat is unusual within the local climate.  ……….The bulk of heatwaves at each location are low intensity with local communities expected to have adequate adaptation strategies for this level of thermal stress.  Less frequent, higher intensity heatwaves are classified as severe and will challenge some adaptation strategies, especially for vulnerable sectors such as the aged or the chronically ill.”

After some digging, I found this paper which describes the Bureau’s methodology used in their Pilot Heatwave Forecast:

The Excess Heat Factor: A Metric for Heatwave Intensity and Its Use in Classifying Heatwave Severity, John R. Nairn and Robert J. B. Fawcett (2015)

The method is quite easy to follow and implement, and I was able to replicate results for the 2014 Melbourne heatwave exactly and use it successfully for other single locations.   It is designed for use with AWAP gridded data of course to give forecast maps.  Note this is raw data, not homogenised.  I downloaded all data from Climate Data Online.

There are several steps.  Readers should read the paper for full details.  Briefly, using a daily mean temperature calculated by averaging the day’s maximum and the following night’s minimum, three-day means are calculated.  These are then compared by subtracting the previous 30 days’ daily means (as people acclimatise to changed temperatures in this period).  Differences that exceed the 95th percentile of all three-day means from 1971 to 2000 are multiplied by the three-day mean to give the Excess Heat Factor, which indicates heatwave.  This is then compared with the 85th percentile of all positive EHFs from 1958 to 2011 to give a severity index, and if it exceeds 3 times the 85th percentile this becomes an extreme heatwave event.

From the paper:

The intent of these definitions is to create a heatwave intensity index and classification scheme which is relative to the local climate. Such an approach is clearly necessary given the abundant evidence that people and supporting infrastructure are largely adapted to the local climate, in physiology, culture and engineered supporting infrastructure.”

Here are the results for Melbourne- with all its UHI effect of course.

Fig. 1: Decadal (running 3653 day) count of positive Excess Heat Factor (heatwave) days in Melbourne

Decadal cnt pos EHF days Melbourne

Fig.2: Decadal count of Severe Heatwave Days

Decadal cnt severe HW days Melbourne

Fig.3:  Decadal Count of Extreme Heatwave Days

Decadal cnt extreme HW days Melbourne

Notice how Melbourne heatwaves of all types have been increasing and extreme events are currently at the highest level “ever”.

How does this apply to various other Australian locations?  I decided to check with the extremes- the hottest and the coldest Australian locations, Marble Bar in the north west of W.A. and Mawson Base in Australia’s Antarctic Territory.

Fig. 4:


The old Marble Bar station closed in 2006.  I have concatenated the old Marble Bar data with the new, from 2003. This makes very little difference to the calculations but extends the record to the present.

Fig. 5: As for Melbourne, decadal count of heatwave days

pos EHF days marble bar 2

Fig. 6:  Severe heatwaves

count severe HW days marble bar 2

Fig. 7:

count  extreme HW days marble bar 2

It is clear that local climate does make a big difference to heatwaves by this definition.  In fact, Melbourne has more extreme heatwave days than Marble Bar!

How does this method of detecting and measuring heatwaves deal with Marble Bar’s record heatwave of 1923-24?

According to the Australian Government’s website, Disaster Resilience Education for Schools at

“Marble Bar in Western Australia holds the record for the longest number of hot days in a row: the temperature was above 37.8°C for 160 days in 1923-24.”

I count 158 days consecutively from daily data at Climate Data Online.  The total for the 1923-24 summer from 13 October to 19 April was 174 days.  That is indeed a long period of very hot weather.

Surprisingly, the BOM does not class that as a long or extreme heatwave.  Apparently, according to this metric, there were only four short heatwaves, one of them severe, and none extreme.  For the entire period, there was only one severe heatwave day – 3 February.

Fig. 8:  Marble Bar 1923-24 summer.  I have marked in the old “ton”, 100 F, or 37.8C.  Squint hard to see the “severe’ heatwave around 3 February, but the heatwave around 22 February is invisible to the naked eye.

EHF Marb Bar 1923 1924 2

Yes, the old timers at Marble Bar were pretty tough and would be used to hot conditions.  But not to recognise this old record heatwave when every day in over five months was considerably above body temperature is laughable.

For comparison, Figure 9 shows 182 day counts of days that were over 100 degrees Fahrenheit, or 37.8 degrees Celsius.  (The old record finishes in 2006.)

Fig. 9:  Running 182 day counts of days over 100 F.  1923-24 is circled.

Days 100F Marb Bar

Note there were two other years when there were more than 170 days over 100F.

Figure 10 is from Figure 16 in the Nairn and Fawcett paper, and is a map of the level of Excess Heat Factor across Australia during the heatwave of January-February 2009.

Fig. 10:  Figure 16 from Nairn and Fawcett (2014)- Excess Heat levels across Australia 21 January – 11 February 2009.

Fig16 from paper max ehf 2009

The area around Marble Bar has a level of between 0 and 10.  My calculations show this is correct- EHF reached 0.08 on 23 January- a mild heatwave.  Readers may be interested to know that maximum temperature was above 40 degrees Celsius from 1 January to 24 January, and minima were not below 24.3.

The authors, and their employer, the Bureau, are in effect telling Marble Bar locals their heatwaves don’t rate because they’re used to the heat.

Now I shall turn to the other extreme- Mawson.

Firstly, plots of the range of minima for each day of the year:

Fig. 11:  Scatterplot of minima for each day of the year at Mawson Base

minima v day Mawson

Fig. 12: maxima:

maxima v day Mawson

Fig. 13:  Decadal count (running 3653 day count) of days with positive Excess Heat Factor, i.e., by definition, heatwave days

Decadal cnt pos EHF days Mawson

Fig. 14:  Decadal count of days in severe heatwave:

Decadal cnt severe HW days Mawson

Fig. 15:  Decadal count of days in Extreme heatwave:

Decadal cnt extreme HW days Mawson

Apparently, Antarctica gets more extreme heatwave days than Melbourne, or Marble Bar!

Of course, critics will say this metric was never intended for use in Antarctica, and I agree: no one would seriously claim there are heatwaves there.  However, if heatwaves are to be defined as “a period of at least three days where the combined effect of high temperatures and excess heat is unusual within the local climate”, and NOT by comparison with any absolute threshold, then this analysis of its use there is valid.  “High” temperature by this definition is relative to the local climate, wherever “local” is. If this metric fails in Antarctica, it fails everywhere.


The Bureau of Meteorology’s metric for heatwaves is a joke.  It may accurately detect heatwaves in the southern fringe of Australia, and a further use may be to support Dr Vertessy’s outlandish claims.  However, it fails to cope with different climates, particularly extremes.  A methodology that fails to detect heatwaves at Marble Bar, and creates them in Antarctica, is worse than useless- it is dangerous.

After 15 Weeks, the Bureau Responds With Non-Answers

July 16, 2015

On 30 March 2015, in response to some “interesting” claims made on ABC Radio by Dr Bob Vertessy, the head of the Bureau, I sent by the normal feedback channel four questions, summarised below:

Q.1: Can you please supply me with a reference to your data that show that the number one cause of death is heatwave?

Q.2:  Can you please supply me with a reference to your data that show five times as many very serious heatwaves today compared with the middle of last century?  Could you also please tell me your criteria for a very serious heatwave.

Q.3:  In what way can 38.9%, 36%, or 34.1% difference in quadratic change (between trends of the supposedly “raw” Australian Water Availability Project data and those of the ACORN-SAT dataset) be interpreted as “no difference”, “exactly the same story”, or “the same result”?

Q.4:  When can we expect to see the results of this further work (monthly and seasonal analysis of differences between AWAP and ACORN) published on the ACORN-SAT website?  If it is available elsewhere please refer me to it.  I am particularly interested in any difference in quadratic change in summer maxima between AWAP and ACORN-SAT, as this is relevant to heatwave analysis.

I followed up with reminder queries on 28 April, with an email to Bob Baldwin (the Parliamentary Secretary responsible for this farce the Bureau) on 1 May, a Formal Complaint on 18 May, another email query to him on 15 June, and phone calls to his office on 25 June and 10 July.  In this last phone call I mentioned that I would approach the Opposition Environment Shadow Minister (Mark Butler) if I didn’t get a reply soon.

A reply was emailed to me on Tuesday 14 July.

Unfortunately, Baldwin’s reply contains no straight answers, avoids answering questions, gives misleading answers, contradicts itself, makes debateable interpretations, has at least two links to references that are not valid, and makes no apology or explanation for the delay.

Here is the full text of Baldwin’s reply, emailed on Tuesday 14 July, followed by my comments.

“I refer to your email of 1 May 2015, concerning an email sent to the Bureau of Meteorology’s Queensland Regional Office regarding an ABC radio interview with the Director of Meteorology.

As I am sure you can appreciate, the Bureau deals with a number of important issues in the interests of the public, including many severe weather events across the country.  As such, the Bureau does not always have the capacity to provide detailed and tailored responses to the many individual enquiries they receive.  I have, however, requested that the Bureau provide a full explanation to the four questions you raised in your email dated 30 March 2015.  The responses are below:

1.  Heatwaves kill more Australians than any other natural disaster.  As outlined in Coates et al (2014), from 1844 to 2010, extreme heat events have been responsible for at least 5,332 fatalities in Australia, and since 1900, 4,555: more than the combined total of deaths from all other natural hazards.  Refer:

-Coates, L., K. Haynes, J. O’Brien, J. McAneny and F.D. De Oliviera (2014)Exploring 167 years of vulnerability. An examination of extreme heat events in Australia 1844-2010. Environmental Science & Policy, 42, 33-44, doi:10.1016/j.envsci.2014.05.003.


-Queensland University of Technology (2010) Impacts and adaptation response of infrastructure and communities to heatwaves: the southern Australian experience of 2009, report for the National Climate Change Adaptation Research Facility, Gold Coast, Australia.


2.  The duration, frequency and intensity of heatwaves have increased across many parts of Australia, based on daily temperature records since 1950, from when coverage is sufficient for heatwave analysis.  Days where extreme heat is widespread across the continent have become more common in the past twenty years.  Refer:

-Perkins, S.E., L.V. Alexander and J.R. Nairn (2012) Increasing frequency, intensity and duration of observed global heatwaves and warm spells.  Geophys. Res. Let.., 39, L20714, doi:10.1029/2012GL053361.


-Perkins, S.E., (2015) A review on the scientific understanding of heatwaves- their measurement, driving mechanisms, and changes at the global scale.  Journal of Atmospheric Research, submitted.

There are many valid ways to characterise discrete heatwaves and warm spells.  The Bureau has adopted a particular operational heatwave definition motivated by human health considerations, defined as a period of at least three days where the combined effect of high temperatures and excess heat is unusual within the local climate.  This does not preclude the use of other heatwave indices suitable for various research questions.  The bulk of heatwaves at each location are low intensity with local communities expected to have adequate adaptation strategies for this level of thermal stress.  Less frequent, higher intensity heatwaves are classified as severe and will challenge some adaptation strategies, especially for vulnerable sectors such as the aged or the chronically ill.  Refer:

-Perkins, S.E. and L.V. Alexander (2013) On the Measurement of Heat Waves, J. Climate, Vol. 26, No. 13, pp.4500-4517. Doi: 10.1175/JCLI-D-12-00383.1)


-Bureau of Meteorology Pilot Heatwave Forecast:

3.  As shown in the figure below, both adjusted and unadjusted temperatures show that Australia’s climate has warmed since 1910.  Most of this warming has occurred since 1955, when adjusted and unadjusted data are virtually identical.

BOM awap-acorn graphic

4.The Bureau continues to monitor and research Australian temperatures.  This work is ongoing, and not being conducted as part of a specific project.  Therefore, the work is undertaken as resources allow, and not subject to specific milestones and timelines.  However, all significant research will be published and made available in the scientific literature following its completion and peer review.

The Bureau of Meteorology puts a great deal of time and effort into producing research and services around climate variability and change.  The Bureau shares observations daily with the world and its research is peer reviewed and published in high quality international journals for everyone to see.

Noting the wide public availability of scientifically robust climate data and information, I encourage you to seek answers to questions through the publicly available information, such as the references provided above.  The Bureau can provide any further analysis and response on a cost-recovery basis, in line with Australian Government Cost Recovery Guidelines.

Thank you for writing on this matter.

Yours sincerely

Bob Baldwin”


There is no mention of my Formal Complaint, just my first email to Baldwin’s office.

There is no apology, and no explanation for the delay in replying by either the Bureau or Baldwin.

Response to Question 1: 

Why doesn’t Dr Vertessy just admit he may have misled listeners by not specifying that heatwaves are the number one cause of death “in natural disasters”?

Coates et al do indeed show that heatwave deaths exceed those of other natural disasters since 1844.

Figure 1:   From Coates et al (2014)- heat related deaths 1844-2010 (click to enlarge)

Coates graph

However, they clearly show that the number of deaths (and much more so, the death rate) was consistently much higher in the first 75 years of last century than the past 40 years, and while the 2009 heatwave certainly caused a spike in the number of deaths, the mortality rate per 100,000 was eclipsed by the 1896 heatwave, as well as 1908 and 1939, and also 1910, 1912, 1914, and 1927.  It appears from this graphic alone that “very serious heatwaves” were more common in the past than recently.

Figure 2 shows the average daily death rate per 1,000 for Australia from 2002 to 2012 taken from Australian Bureau of Statistics data (monthly death rate divided by the number of days in each month).  It is clear that mortality peaks in late winter, and is lowest in summer (December – April).

Figure 2: Daily Mortality Rate per 1,000 Population, 2002 – 2012

Daily mortality

Unfortunately, cold spells are not recognised as natural disasters, as they occur every year.  Deaths from cold are not limited to hypothermia, or burial under snow, or crashes on slippery roads, or house fires caused by heaters.  Every winter the death rate rises significantly as the sick and elderly succumb to chronic cardio-pulmonary illness, influenza, and pneumonia.  Cold is the real “silent killer”.

Response to Question 2:

Notice how my question, specifically querying five times as many very serious heatwaves today compared with the middle of last century, which is what Dr Vertessy claimed, has been neatly avoided.  The Bureau merely states that heatwaves “have increased”.  Dr Vertessy’s outlandish claim cannot be substantiated.

After quoting Coates et al in answer to the previous question, the Bureau now claims heatwaves can only be analysed since 1950.  If that is so, we can ignore the 70% of all heatwave deaths that occurred between 1900 and 1949, as only 1,378 heat related deaths occurred between 1950 and 2010 (see Figure 1 above).  While exact figures are not available to me, it would be interesting to see the total for floods, cyclones, bushfires, storms, tornadoes, earthquakes and landslides for this period, and whether 1,378 heat related deaths exceeds this.  Does the Bureau not see this contradiction?

Further, Perkins et al (2012) finds increased heatwave trends in percentage of days per season are “confined to… southern Australia”, not “many parts of Australia” as claimed in Baldwin’s reply, which is therefore misleading.  The claim that “days where extreme heat is widespread across the continent have become more common in the past twenty years” is not supported by evidence in this reply, as the second Perkins paper referenced is not yet published.  True or not, this is irrelevant.

Unfortunately, the link to the third Perkins paper does not work.  The Bureau’s Heatwave Forecast appears to be based on a similar metric to that used by Nairn and Fawcett (2015) in calculating an Excess Heat Factor to identify and predict heatwaves.  This at least will be useful.

Response to Question 3:

Again, the Bureau has chosen to avoid answering my question, clinging to their meme of warming since 1910, which I did not dispute, and that the difference between AWAP and ACORN since 1955 is negligible, which also I did not dispute.  My question was whether this negligible difference was evident from 1911, which the Bureau’s own paper (CTR-050) shows to be false.

Response to Question 4:

A short answer to my query would have been “No”.  No analysis of the difference between AWAP and ACORN on a monthly or seasonal basis has been undertaken.  Apparently I am the only person to have done this, and my results showing massive differences in maxima trends, largely due to just two adjustments, have not been falsified.

The final paragraph of Baldwin’s reply could be paraphrased as “Don’t ask us any more awkward questions.  If you do, you can expect to pay for the privilege of waiting three months to get a non-answer”.

Dr Vertessy has failed to substantiate his claims.  After 15 weeks, the Bureau has been forced to make a reply, which avoids answering questions, gives misleading answers, contradicts itself, makes debateable interpretations, has at least two links to references that are not valid, and makes no apology or explanation for the delay.  Thankfully, it does give references to some papers that give some information on heatwave detection.

What a farce.  I am disappointed, but not surprised.

However, I do think Dr Vertessy’s forays into the media world will be much more carefully scripted in future.

“Pause” Update

July 9, 2015

With the release of June data, showing the marked impact of a moderately strong El Nino, using UAH v. 6.0 data I have calculated the longest period back that the length of the pause in tropospheric temperature has been less than +0.01 degrees Celsius per 100 years:


uah pause globe 0615

North Polar:

uah pause npol 0615

Northern Hemisphere:

uah pause nh 0615


uah pause tropics 0615

Southern Hemisphere:

uah pause sh 0615

South Polar:

uah pause spol 0615


uah pause oz 0615


uah pause usa 0615

The El Nino will affect the length of the pause in some regions, but not all.  The pause continues!

The effect of two adjustments on the climate record

June 24, 2015

The warming bias in Australia’s ACORN-SAT maximum dataset is largely due to just two adjustments.

Last week’s Report of the Technical Advisory Forum’s review of the ACORN-SAT temperature reconstruction produced some rather bland, motherhood type statements.  However, hidden in the public service speak was a distinct message for the Bureau of Meteorology: lift your game.  Two of the areas I have been interested in are (a) whether individual adjustments are justified, and (b) the effect of these adjustments on national and regional temperature trends.  In this post I look at adjustments at just two sites, which are responsible for the single largest increase in national trend.

On page 17 of the Report we find the following graphic:

Fig. 1: Scatterplot of difference between AWAP and Acorn annual mean temperature anomalies.

scatterplot awap acorn mean diff

This is a clear statement of how much Acorn adjustments have cooled past temperatures, as AWAP is regarded as being only “partially homogenised”, and close to raw temperatures.   There is a considerable difference- more than 0.2 degrees- between the two interpretations of temperatures 100 years ago.

Mean temperature is the average of maximum and minimum.  In this post I shall look at just maximum temperatures, from 1911 to 2013.  The following graph is a plot of the difference between monthly Acorn and AWAP maximum anomalies, which I think is much more informative:

Fig. 2:

scatterplot awap acorn max months

Note there is a trend of +0.22 degrees / 100 years in the differences, indicating a predominance of cooling of earlier data; there is a very large range in the first 50 years, from about -0.7C to +0.3C, and one outlier at +0.4C, reducing to a much narrower band in the 1960s before increasing in the last 20 years; and the bulk of differences are negative before 1970.

Now let’s look at what has been happening in the past 35 years- in fact, in the satellite era:

Fig. 3: Monthly differences between AWAP and Acorn before and after December 1978

scatterplot awap acorn max phases

The trend in differences for the first 67 years is 0.33C / 100 years, but there is a very small tendency for Acorn to be cooler than AWAP recently- and the range of differences has been increasing.

That’s an interesting find, but I want to examine in more detail the effect of the adjustments which cause those differences.  Here are annual maxima in AWAP compared with Acorn.

Fig. 4: Annual mean of monthly maximum anomalies: AWAP and Acorn

graph awap acorn max

Again we see that Acorn has increased the warming trend from +0.59C to +0.81C per 100 years, an increase of +0.22C, or 37.3%.

However, the difference appears more marked before the mid 1950s.  The next graph shows the trends from 1911 to 1955 compared with the trends from 1956 to 2013.

Fig. 5: Comparison of trends in maxima before and after the middle of the 20th Century.

graph awap acorn phases

Note: while the trends of AWAP and Acorn are very similar (+1.32 to 1.4C per 100 years) since the 1950s- which the Bureau never tires of proclaiming- before then the plot tells a different story.  Acorn reduces the cooling trend by 0.44C per 100 years, a reduction of 86%.

How was this achieved?

On page 44 of the technical paper CTR-050 we find this explanation:

Returning now to maximum temperature, the differences between the AWAP and ACORN analyses show a marked drop in the early 1930s, with a sudden decrease of about 0.15 °C. This is most likely attributable to substantial negative adjustments between 1929 and 1932 in the ACORN-SAT dataset, indicating substantial discontinuities (expressed as artificial cooling) at a number of individual locations with a large influence on national analyses, because of the sparsity of data in their regions in that period. These discontinuities are mostly related to site moves that are associated with concatenated records for single locations. These include Alice Springs, Kalgoorlie and Meekatharra. Alice Springs, where the adjustment is associated with a site move in late 1931 or early 1932 from the Telegraph Station to a climatologically cooler site in the town, has a notably large “footprint”; at that time there were only two other locations within 600 kilometres (Tennant Creek and Charlotte Waters) which were observing temperatures, while the nearest neighbours to the west (Marble Bar and Wiluna) were more than 1200 kilometres away.

This large change between AWAP and Acorn is shown in the next graph.

Fig. 6: 12 month mean difference in monthly maxima anomalies

graph awap acorn diff 1930 drop

As I explained in my post in September 2014, Acorn sites are homogenised by an algorithm which references up to 10 neighbouring sites.  A test for the validity of the adjustments is to compare the Acorn site’s raw and adjusted data with those of its neighbours, by finding the differences between them.  Ideally, a perfect station with perfect neighbours will show zero differences: the average of their differences will be a straight line at zero.  Importantly, even if the differences fluctuate, there should be zero trend.  Any trend indicates past temperatures appear to be either relatively too warm or too cool at the station being studied.  My aim is to check whether or not individual adjustments make the adjusted Acorn dataset compare with neighbours more closely.   If so, the trend in differences should be close to zero.

I have tested the three sites named above.  I use differences in anomalies calculated from the mean of maxima for the 30 year period centred on 1931, or for the period of overlap if the records are shorter.  The neighbours are those listed by the Bureau on their Adjustments page.

Fig. 7:  Meekatharra differences from neighbours (averaged)

Meek acorn v neighbours avg

Note that the Acorn adjustment (-0.77C at 1/1/1929- the adjustment of +0.54C at 1/1/1934 does not show up in the national signal) is indeed valid: the resultant trend in differences is close to zero, indicating good comparison with neighbours.  However, since Meekatharra’s record starts only in 1927, two years of the Meekatharra adjustment cannot have had a large influence on the national trend as claimed.

Fig. 8:  Kalgoorlie differences from neighbours

Kalg acorn v neighbours avg

Kalgoorlie’s steep cooling compared with neighbours (from 170 km to 546 km away) has been reversed by the Acorn adjustment (-0.62C at 1/1/1930- the adjustment of -0.54C at 1/12/1936 does not show up in the national signal), so that Kalgoorlie now is warming too much (+1.02C / 100 years more than the neighbours).  Kalgoorlie’s adjustment is too great, affecting all previous years.

I now turn to Alice Springs, which ‘has a notably large “footprint”’.  Too right it does- its impact on the national climate signal is 7% to 10%, according to the 2011 Review Panel, p. 12.

Fig. 9:  Alice Springs differences from neighbours

Alice acorn v neighbours avg

Alice Springs, cooling slightly compared with neighbours, has been adjusted (-0.57C at 1/1/1932) so that the Acorn reconstruction is warming (+0.66C / 100 years) relative to its neighbours.  The adjustment is much too large.

And exactly where are these neighbours?

Tennant Creek (450 km away), Boulia (620 km), Old Halls Creek (880 km), Tibooburra (1030 km), Bourke (1390 km), and Cobar (1460 km)!

The site with the largest impact on Australia’s climate signal has been “homogenised” with neighbours from 450 km to 1460 km away- except the adjustment was too great, resulting in the reconstruction warming too much (+0.66C / 100 years) relative to these neighbours.  The same applies at Kalgoorlie.  Meekatharra’s record only starts in 1927 so its effect can be discounted.  These are the only remote Acorn sites that had large adjustments at this time.  All other remote Acorn sites open at this time either have similar trends in raw and Acorn or had no adjustments in this period.

The 37.3% increase in the trend of Australian maxima anomalies in the “world’s best practice” ACORN-SAT dataset compared with the “raw” AWAP dataset is largely due to just two adjustments- at Kalgoorlie and Alice Springs- and these adjustments are based on comparison with distant neighbours and are demonstrably too great.

If it wasn’t so serious it would be laughable.

Peak Warmth?

June 17, 2015

Global Warming Enthusiasts have held the floor for too long.  It is time for genuine climate scientists to take the initiative and adopt, address, and promote the concept of Peak Warmth.

What exactly is Peak Warmth?

The well-known concept of Peak Oil is the point in time when the maximum rate of extraction of petroleum is reached.  Peak Warmth is an unrelated but similar concept.  Peak Warmth is that point when global temperatures inevitably reach their maximum before beginning to cool.  Included in our discussion of the hiatus, pause, slowdown, or plateau in global temperatures, which may be followed by temperatures going up, down, or sideways, we need to consider Peak Warmth, as its consequences could be enormous.

The first thing to note of course is that Peak Warmth is well and truly past- in fact, around 5,000 to 8,000 years past.  Many studies from around the world show the Holocene Optimum was from one to several degrees Celsius warmer than now, in different regions of the globe.   The previous Eemian interglacial appears to have been even warmer.    The Holocene has also had periods of millennial-scale variability in temperature and precipitation (think Mediaeval Warm Period, Little Ice Age).  In various parts of the world, regional temperature change of four degrees Celsius in a century has not been unusual, so there’s nothing unprecedented about recent warming.

However, the focus of this post is the recent warming of the past 160 years.

Fig. 1:  Hadcrut4 since 1850

WFT hadcrut4

Global Warming Enthusiasts can see no end to the recent warming, at least not without massive cuts to greenhouse gas emissions.  They need to be pinned down: what will happen after 2100?  Will there be runaway warming?  Will temperatures continue to rise, and by how much?

Sceptics of the validity of the IPCC’s global warming scenarios have a different view.  If the recent temperature increase is mainly due to natural causes, then a decrease at some stage is very likely.   Some sceptics will say that natural influences will shortly cause (or have already caused) temperatures to begin cooling.  Others (including myself) will say “We don’t know and can’t predict what will happen, or when”.   We note, however, that going by the past, future cooling is inevitable- the instrumental record, such as it is, shows short warming phases are followed by cooling.  The Dark Ages followed the Roman Warm Period, and the Little Ice Age followed the Mediaeval Warm Period.  And while we don’t know the timing or mechanism of glacial inception which could be decades, centuries, or millennia away, we are overdue for the next glaciation.

Are there any indications of Peak Warmth?  Arguably one of the best temperature datasets is that of the satellite derived UAH (University of Alabama- Huntsville).  The Temperature of the Lower Troposphere gives a good indication of what the bulk of the atmosphere is doing.  Unfortunately, we only have data since December 1978.

Fig. 2: UAH monthly temperature anomaly data for the Globe, December 1978 to May 2015. (The x-axis labels show December of each year.)

uah globe 7915 phases

During the satellite era, the global temperature record shows 15 years of modest warming, then a rapid increase between the early 1990s and 2001 – 2002.  (This period includes but is independent of the 1997-1998 Super El Nino.)  The pause is undeniable since then- a bit over 13 years.

Actually, it is a small cooling.

Fig. 3: Phases of warming and cooling in UAH data

uah globe 3 trends

For the benefit of those who think including the Super El Nino exaggerates the trend of the rapid warming phase, excluding 1997, 1998, and 1999 gives a trend of +1.54C- just 0.07C less.

While we can say that current temperature trends are not consistent with IPCC projections, and alternative climate scenarios must be considered, it is too early to say whether we have reached or passed Peak Warmth of the current warm period, or if there will be future warming phases to a higher peak.  We won’t know until many years afterwards.  It is possible that Peak Warmth will be identified as occurring in a single month or year (for example, April 1998), but it is also possible that it will be seen as a period of some decades or even centuries.

I hope I am not around to see the cooling which will follow Peak Warmth.  A long plateau at about current temperatures, or even a small decline, would not be detrimental for the world, but unlike Elsa, cold does bother me.  While I have great faith in the ability of humankind to adapt to future challenges, another Little Ice Age would have very serious consequences for world food production, and the next glacial period must surely bring an end to civilization as we now know it.

It is time for genuine climate scientists to adopt and address the concept of Peak Warmth.  The Precautionary Principle, invoked to justify measures to combat or mitigate global warming, needs to be invoked to address the consequences of future global cooling.  Myopic denial of the pause wastes time and resources which must be better spent in studying little understood influences on climate such as clouds, rather than the current fixation on greenhouse gases as a cause of warming to the exclusion of all else.

We do indeed live in interesting times.


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