Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Are Australian Cities Getting Hotter?

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The biggest global warming conference since Kyoto, opened today in Montreal, Canada. The 10,000 experts from 180 nations are to spend the best part of the next 10 days deliberating about how best to “slow the alarming effects of greenhouses gases and global warming”.

I had a look at ‘global temperature’ some weeks ago in my post titled ‘Global Warming for Dummies’, click here. I concluded that globally, 2005 may indeed be the hottest year on record. But I didn’t scrutinize my data source – just accepted the NASA data and methodology.

Not everyone is convinced that it is getting hotter.

At this blog I encourage the contrarian position. To quote David Tribe, “It’s how we treat our contrarians that tells us whether we are living in a truely civil society, for the contrarians are very valuable to us, because they point to the places where ‘conventional wisdom’ may be getting it wrong.”

Global warming skeptic Warwick Hughes has had a good look at the data for Australian capital cities at the NASA site. In the following guest post from Warwick Hughes he disputes the main premise of a recent Bureau of Meterology (BoM) media release titled 2005:Australia’s warmest year on record?.

Warwick writes:

The BoM conclusion is based on their specially adjusted data, they choose a start date 1950 which is a cooler part of the record and they ignore all late 19 Century data which in many stations was as warm as recent decades. Furthermore, it seems premature to make claims about 2005 before the year has ended.

A more realistic view of the relative warmth of 2005 placed in century scale perspective is given by the NASA Goddard Institute for Space Studies (GISS) Surface Temperature Analysis, Station Data, available at,
http://data.giss.nasa.gov/gistemp/station_data/.

GISS is run by Dr James Hansen, who I think it is fair to say, has been a ‘global warming proponent’ since at least 1988. GISS data is built from the USA NOAA group’s global GHCN dataset. Looking at records from the “homogeneity adjusted” data choice of GISS for all the Australian capital cities shows that nowhere can the BoM wish come true.

GISS would have adjusted these urban warming affected city stations taking account of surrounding more rural data. I do not agree with everything GISS does and I comment below where I think fit. However NASA/GISS has vastly more experience than the BoM at evaluating temperature trends from the 19C because their dataset is global and Dr Hansen and his team have published a series of papers on global trends over many years.

Let us look at some Australian examples, city by city, using the NASA/GISS dataset, starting with Perth, view image
(30 kbs).

There is no possibility in Perth that 2005 will be Australia’s warmest year on record. I have people from the WA wheat belt telling me of the worst frost damage to water pipes this year that they have seen for decades.

Adelaide has known many warmer years than 2005. Likewise, if the East Sale record was slid up to compare exactly with Melbourne then it is crystal clear that the BoM will need a very hot couple of months for their proposal to come to pass in south eastern Australia,view image (30 kbs).

It is obvious that 1999, 2000 and 2001 were warmer than 2005 in Hobart so the BoM has no case yet around Hobart that 2005 has been Australia’s warmest year on record, view image(30kbs). Interesting that Maatsuyker Island Lighthouse is showing much less warming than Hobart airport so the adjusted GISS data for Hobart airport may still carry urban warming, further weakening any BoM case.

The best guide for Sydney and Newcastle is to see where 2005 at Williamtown relates to the Newcastle century long data, which is from Nobbies Signal Station, view image (30kbs). From this graph it is obvious that there is no possibility in Sydney and Newcastle that 2005 has been Australia’s warmest year on record. It is equally obvious that the Sydney Airport data, affected as it is by a strong ‘urban heat island’ (UHI) effect, is artificially warming at a rate much faster than Williamtown despite any GISS adjustment.*

Moving north to Brisbane and it is obvious in this region that if the Eagle farm data was ‘merged’ with the old Brisbane Regional Office trend then there is no chance that 2005 has been Australia’s warmest year on record, view image (30kbs).

At this point we have to ask ourselves, “Where in Australia is this unprecedented warming the BoM talking about?”

Checking the circa 125 years of data from Darwin it is obvious that 2005 is a warm year but it was topped by 1998, might equal 1988 and will be topped easily by 1973, view image (30kbs). It is also obvious that if the airport data are merged with the earlier Post Office data then several years 1906 and earlier would have been warmer than 2005. Hence in this area the BoM claim that 2005 has been Australia’s warmest year on record, is not borne out by the data. The GISS team do provide on their web page a full Darwin record splicing the post office and airport but in my opinion it is not one of their better efforts and I prefer my own splice. If anyone prefers the GISS Darwin from 1882 then it makes no difference to the above yearly comparisons.

Moving now to Central Australia for our last graphic, that of the circa 125 year long Alice Springs temperature record. In this case, GISS do not provide a circa 125 year long record in their “homogeneity adjusted” data, but if readers make a graph for Alice Springs from the GISS Dataset listed in their “pull down menu” as “after combining sources at same location”, then you will see a graphic very similar to mine below showing that almost a dozen years have been warmer than 2005, view image (30kbs).

So it seems doubtful that Alice Springs data will provide confirmation for the BoM that “2005 has been Australia’s warmest year on record” but the data at years end will tell.

…………….

* Sydney airport is used by the Jones et. al. team at the University of Norwich, to compile the ‘global warming’ trends we all know so well. For my ’20th Anniversary Review’ of the unsound Jones et al 1986 methodologies, see
http://www.warwickhughes.com/cru86/ .

…………….

Warwick Hughes temperature outlook critiques for 2005 are at,
http://www.warwickhughes.com/cool/cool14.htm. Temperature Outlook critiques pre 2005 are at, http://www.warwickhughes.com/climate/cool8.htm.

Reader Interactions

Comments

  1. Louis Hissink says

    Speaking with locals, and I have lived here since 1971, our present coolish weather in Perth is considered “normal”.

    When I was a teenager and lived in Sydney, Lifesaving duties at North Narrabeen SLSC started in October when the swimming season started, and it was always hot mid November to mid February. Lately the climate has significantly cooled.

    I suspect there some very specious science and statistics are being used to predict this climatic catastrophes.

    In anycase simply averaging temperatures in gridcells is fundamentally wrong – but then as little science is taught these days, no one understands the difference between intensive and extensive variables.

    Herein is the start of the error.

  2. rog says

    Some years it was very hot early October with bushfires and fatalities. I always remember October long weekend as being a hot one. This is the time when the water tanks run dry and the zuchinis grow enormous overnight. I also remember the end of the school year as being hot with cicadas everywhere and kids fainting during assembly (woops there goes another one).

    This year, apart from Melb Cup day and maybe a couple of others it has been exceptionally cool. And rainy. Weird. Or maybe my memory is playing tricks on me?

  3. Neil Hewett says

    With a lack of heating and winter apparel, I historically bemoan the six weeks about the Daintree’s winter solstice for the coincidence of almost unendurable cold (6 deg. C) and the onslaught arrival of peak visitation.

    Presenting World Heritage values on nocturnal wildlife-spotting tours is most difficult in these conditions.

    The demands of presentation (on a nightly basis over eleven consecutive years) has brought about a sensitivity to temperaure in terms of wildlife activity.

    I have been mollified over the last six or so years, by significantly warmer but longer cold periods.

    In the same period, dry season temperatures have brought about disapppointing rainfalls that hover around half of our annual expectation of 5.5 metres.

  4. Wadard says

    It’s been hotter than I remember it being here in Sydney. The reason BoM can make the prediction is because it is almost December.

  5. Louis Hissink says

    I think it is technically called Urban Heat Islands in which a concentration of living things and their habitats cause a local increase in temperature.

    Much like 100 eskimos huddling in a large igloo also locally increase the temperature with their body heat etc.

  6. Phil Done says

    Look it’s completely obvious – Warwick has failed to account for the additional neutrino flux in the stations mentioned. Come on.

  7. Phil Done says

    ” At this blog I encourage the contrarian position. To quote David Tribe, “It’s how we treat our contrarians that tells us whether we are living in a truely civil society, for the contrarians are very valuable to us, because they point to the places where ‘conventional wisdom’ may be getting it wrong.” ”

    So where are the GM and alternative land management contrarian raves ?

  8. Louis Hissink says

    Probably because we contrarians feel no need to rave about GM and alternative land management.

    We recognise the problem, fix it on our own bat, and wish the guvmint and its self appointed obersturmfuhrers would get out of our lives.

  9. rog says

    Why should anyone engage with GM and alternative land management contrarians? Where is the profit?

    They only want to project their own emotional grab bag of personal foibles into, what is for them, an alien environment.

    What do greenies know about animal husbandry, crop growing, soil science, resource management, mechanical, structural, civil and hydraulic engineering, market forces, financing, OH&S, quality assurance, corporate compliance, taxation etc?

    Not much

    Numbats

  10. Louis Hissink says

    Profit=Savings=Income-Expenses

    This is an absolute rule in the physical world. It has, however, little relevance in the Land of Oz.

  11. rog says

    Kyoto pronounced deceased;

    Why Kyoto will vanish into hot air
    By Bronwen Maddox

    THE United Nations conference that began yesterday in Montreal and will stretch on for nearly two weeks will fail in its aim: to devise a successor to the Kyoto Protocol on global warming.

    That does not matter; in fact, it is the best outcome. Kyoto has been an extraordinary piece of work. A treaty that its most important signatories have found impossible to meet, and which has changed behaviour very little, has still become a resonant global symbol.
    ————-

    For all the rhetorical mileage which some European countries have found in Kyoto, at the US’s expense, their own “success” — such as it is — is due to a quirk of history rather than to selfdiscipline or the powers of their leaders.

    That gloating is no basis on which to move forward.

    http://www.timesonline.co.uk/article/0,,3-1895038,00.html

  12. Jennifer says

    I think the graphs from Warwick are really interesting. He has provided us with some data -some evidence – for all the state capitals and Alice Springs.
    Are there other parts of Australia where there is a more obvious warming trend and where it does look like 2005 will be the warmest? How is it that the B0M graph (click first link from media release) looks so different to the NASA-Hughes graphs for the cities?

  13. Phil Done says

    I find it incredible that after all the talk on heat islands we’re looking at capital cities ? Have I missed something

  14. Warwick Hughes says

    Phil Done asks, “I find it incredible that after all the talk on heat islands we’re looking at capital cities ? Have I missed something.”

    Good question Phil. If you go back to Jennifer’s original post you will find she quotes me saying;
    “GISS would have adjusted these urban warming affected city stations taking account of surrounding more rural data.”
    OK ?
    Countering BoM propaganda is not simple or easy.
    Using the GISS city trends as I have leads to the following;
    I portray long term station data that is public, that anyone can check;
    data is relevant to where most Australians live;
    updated to near current months;
    my response to the BoM ends up hopefully not too large;
    city data is less “gappy” and stations tend to have greater continuity;
    from a huge research group, independent of Australia with over a decade of global experience in the field;

    I trust that helps people understand why my counter to the BoM media release takes the form that it does.
    The Minister (Senator Campbell) and Undersecretary (Greg Hunt)were emailed my original report.
    Best wishes

  15. Warwick Hughes says

    I see the 29 Nov reference by Neil Hewett to Daintree rainfall which got me curious about long term trends. There are two stations around Cairns in the BoM high quality data that go back near a hundred years which I have graphed and added to my,
    “2005 is unlikely to be Australia’s hottest year.” article which is posted at.

    http://www.warwickhughes.com/cool/cool15.htm

    You need to scroll down to near the end and I have also added temperature trends from Cooktown and Willis Island (Coral Sea). There does not seem to be anything special about recent times in rainfall or temperature data in coastal N Queensland.
    No up to date long term rainfall data from the ranges that I could see.
    If anyone has data let me know.
    Best wishes

  16. Phil Done says

    Warwick – you’re happy enough to use turn of the century data for fine resolution studies?

    And on what basis would you accept NASA/GISS adjustments with your “normal” degree of scepticicm about the ability of institutions to “get it right”?

    What story does BoM’s high resolution data sets tell? What is the spatial view of temperature? In other words – let’s not mess around on tweaking the capitals data – give us the full national picture.

  17. jennifer says

    Phil
    Haven’t you previously written that it is going to get hotter and drier in Australia where most people live? Or was it just drier where most of the people and agriculture are?

  18. Anastasia says

    you need to have graphs to proove that Austalian cities are heating up. The info isnt enough.

  19. jennifer says

    Anastasia
    Click on where it says ‘view image’ and you will see Warwick’s graphs for all the state capitals.
    It would be good to see the equivalent from BoM.

  20. Phil Done says

    Jen – I have previously pointed to the rainfall trend maps on BoM’s site commenting on a drying trend in SW and eastern Australia. Mere observation, plus lots of press coverage of many Australian capitals having water supply problems in recent years. North-west WA (broadly) is getting wetter. I have also said that Australian total rainfall series are not that informative given the spatial vairability patterns.

    see series on

    http://www.bom.gov.au/silo/products/cli_chg/

  21. Phil Done says

    Jen – I was merely pointing out that if were interested in whether Australia was warming we’d be steering clear of cities and heat islands (interesting though that may be for settling pub arguments about the weather) and concentrating on a well sifted set of quality stations across the continent. i.e. a broad spatial view.

  23. jennifer says

    A couple of comments:
    1. I get excited about graphs. I reckon it is great to get the overview and it is great to look at individual localities – to get an idea of the variability.
    It seems to me that Phil suggests we should get the overview for temperature but look at the variability with respect to rainfall? Hey, you can’t expect to have it both ways!
    2.I did title this post “Are Australian cities getting hotter” because Warwick sent me graphs for the cities. The title of the post doesn’t distinguish between ‘getting hotter’ because of global warming versus ‘getting hotter’ because of heat island effect. I would be keen to post something which looks at this issue with graphs – presents data for cities and data for the entire country with and without the adjustments for heat islands. Is this information already available somewhere?

  24. Phil Done says

    err … no

    interested in spatial patterns for both temp and rainfall. I am consistent (well on this at least).

    And there’s temporal variability and spatial variability – you need to look at both. The url given above sort of helps with that to some extent.

    If your interest is in GW I’d only be interested in quality well maintained stations that are as free as possible from changing urban infrastructure effects. I believe BoM undertake temperature trend analyses using such stations.

    If Louis gets the Australian raw met data from BoM he could do any maps and plots the blog wants !! And why not do a training run on Aussie before taking on the world data sets.

  27. Louis Hissink says

    Urban heat island effects – just how are these compensated for, and what is the theoretica basis for those compensations?

    One for you Phil.

  29. Richard Darksun says

    The temperature trends in the citys are worrying even if GW is not all of the cause. This is where all the population is and we get a increase in death rates in heat wave events as it is. We sure do not want to the situation to get worse. It is clearly worthwhile maintaining a “city” based network and a “unimpacted” network for climate analyses. One really has to ask if we, as a nation are putting enough resources into quality long term monitoring (climate, hydrology, ecosystems, land management practises). The density of BoM volunteer rainguages has declined from the peak in the 1970’s, just great when we are trying to determine rainfall and climate trends. Solar radiation, pan evaporation appear to be far far from optimal. Increased density of temperature recordings would help sort out the “heat island” effect. Has any one run a series of transects of thermoneters out from city centers and compared results over several years? It seems the logical experiment.

  30. Richard Darksun says

    The temperature trends in the citys are worring even if GW is not all of the cause. This is where all the population is and we get a increase in death rates in heat wave events as it is. We sure do not want to the situation to get worse. It is clearly worthwhile maintaining a “city” based network and a “unimpacted” network for climate analyses. One really has to ask if we, as a nation are putting enough resources into quality long term monitoring (climate, hydrology, ecosystems, land management practises). The density of BoM volunteer rainguages has declined from the peak in the 1970’s, just great when we are trying to determine rainfall and climate trends. Solar radiation, pan evaporation appear to be far far from optimal. Increased density of temperature recordings would help sort out the “heat island” effect. Has any one run a series of transects of thermoneters out from city centers and compared results over several years? It seems the logical experiment.

  31. Phil Done says

    There is a thing called the Australian Reference Climate Network

    http://www.bom.gov.au/climate/change/reference.shtml

    Might help yo’all to read. BoM have put a lot of work in here.

    http://www.bom.gov.au/cgi-bin/silo/reg/cli_chg/trendmaps.cgi

    As for trends in max temp or mean temp, “No map is available for this selection”

    TRY putting in a time period. Works for me.

    Urban heat islands are compensated for by not selecting stations thus affected. No need to compensate.

    The long term fate is a major concern for all Australians – particularly those involved in agriculture and water resource management, whether you’re studying climate variation, or seasonal forecasting, or looking at climate change. We are most lucky to have the record we do. And very grateful to many volunteer observors who has studiously maintained stations for long periods. True grit.