Well we can actually compare Melbourne to Laverton, which is just a good 15 minute drive from the Melbourne site. Whilst we don't expect the two to follow suit exactly, with only a small driving distance between them we should expect only small white noise errors if there was no problem with urban warming.
Unfortunately this is not what we get. Starting from 1955, shown below is the difference between Melbourne and Laverton temperature anomalies for average temperature (average of max and min).
The rate of increase is obvious. IN fact it is increasing at more than 2 degrees every 100 years. The minimum temperature increase was even greater at 3 degrees per 100 years or at 3 times the supposed global mean increase due to global warming. The Urban Heat Island effect obviously has a major influence in the temperature data, so much so that at some stations it can increase it by up to 3 times he normal amount.
Whilst there is debate over to its use in global warming analysis. (this website say that it is not used, this article suggests that it is used in much research, and this Australian Bureau of Meteorology website suggests that it is used in temperature maps, as well as a personal email from the BOM that says that it does, and it is also included in the Australian temperature extreme analysis), there are some big applications in these findings.
Firstly, is suggests that the Urban Heat Island effect is real. This goes against research by Peterson (2003) who indicated that "Contrary to generally accepted wisdom, no statistically significant impact of urbanization could be found in annual temperatures.
Parker (2004) suggested that the Urban heat island effect didn't exist because calm nights were as warm and windy nights (huh???).
Even the IPCC (2007) concluded that
"the global land warming trend discussed is very unlikely to be influenced significantly by increasing urbanisation"
If this is the case, can you explain the above graph? And this one as well as shown on this website?
Granted of course, that this is an extreme case. The weather station might well have been plotted on a few squared of grass, but amongst cars, trams, concrete, street lights etc. Not all stations are like this. However whatts up with that suggests that this is far from a one off occurrence.
So if Melbourne's Urban Heat Island Effect makes a 2 degree increase in temperature per 100 years, and a 3 degree increase in minimum temperatures, then how much will a small urban effect make? Half a degree? One degree?
Either way, the IPCC is clearly only kidding themselves that the Urban Heat Island effect is insignificant. The graph above is significant at less than the 0.001 level of significance.
101 comments:
Whilst I agree with you on UHIs, there is a serious issue in measuring urban heat island effects against surrounding rural areas.
As the report yesterday shows (link below) rural areas are much warmer (and drier) than natural bushland.
So while we have urban heat islands, we also have rural heat oceans and it's not clear which effect is larger.
The only valid measure of urban heat island effects is by comparing urban temperatures with areas of natural bushland and not as is currently the case with rural areas.
http://abc.net.au/science/news/
stories/2007/2073363.htm
yes I agree with you Phillip, good post. My post was to compare melbourne to laverton, the former which has changed over the time, the latter which arguably has changed a lesser degree. Hence looking at the amount of UHI.
As you point out the difference between rural and bushland might even be more warming as well, but there isn't a lot of data to compliment this as most stations are rural.
perhaps we can include Giles Meteorological Office as "bushland" despite being in the middle of the desert, as its environmental surroundings have changed little.
Interestingly, either has the temperature.
Jonathan, do you have data on Wittenoom? It's one of the few places we know for certain that anthropogenic effects have decreased, probably to almost zero (there is still a handful of people living in the area) over the last 20 years.
I've been to Wittenoom, blue sky mining! Interesting, yet bizzare place. But no at the moment I dont have data on this place.
On the subject of "reverse urbanisation", Omeo could fit the bill. It was a major goldmining boom town in the late 1800s and has been declining ever since. I don't have definite figures, but the population peaked there before 1914.
Interesting that the temperature trace is cooling.
I was also in Wittenoom, once about 10 years ago. Went there by accident. A couple of places still had sprinklers running. It was at dusk. It was full of Roos come in for a drink, but no lights or people I saw.
How do you explain Gabo Island? It appears to have similar UHI to Melbourne.
Mannie, how could Gabo Island have similar UHI effects to Melbourne?
Mannie, care to post a link to what needs explaining.
I think Mannie is saying that the parts of the world warming the most are the least urbanized. Central Africa, Polar regions etc. How does that work with the Urban Heat Island theory?
Anonymous, unless you can provide data and pictures of the weather station, then your point is mute
http://data.giss.nasa.gov/gistemp/2005/
and the purpose of that link?
It is a global assimilation of weather station data used to determine regions where 20th century warming has occured. Look at the spatial distribution and check for regional heterogeneity, as this will highlight heat island effects. Does it correspond with urbanization? Where is the Melbourne urban heat island effect in any of these plots?
Hmm I'm not usre i'm getting you here. I'm not saying that UHI occurs due to weather stations being in big cities, but rather weather stations being surrounded by concrete, street lights, air conditioners, cars, planes etc. This can easily happen in country towns as easily as cities.
Hence the difference between Melbourne and Laverton.
Then why is the greatest warming occuring in the polar regions and Equatorial Africa? Are polar bears sitting on the temperature sensors? The greatest warming is occuring away from the centers of urbanization, suggesting that even if there is an urban heat effect it is much smaller than the global warming signal. Look at the distribution.
Firstly, I have never doubted that the effect of UHI is less than the general global warming average, but it in my opinion has little to do with urbanisation as opposed to matter surrounding the station. For one example, Wilsoms Prom as shown here does not have urbanisation, but the weather station is surrounded by concrete, and surprisingly Della-Marta et. al (2003) as the highest quality weather station that is not "set in bitumen".
The dataset, and I have only looked at Australia mind you,is riddled with these types of problems, but as I said previously, is not the be all and end all cause of global warming temperature increases.
Most warming is not occuring in polar regions. See link below. Most warming is occuring/has occured in the Siberia/Alaska region.
These are the coldest inhabited areas on earth and highly likely to have had large increases energy for heating over the 20th century. Locally the effect is probably significant and temperatures are almost always measured in or near to human settlements.
I'd say Siberia/Alaska probably has the most pronounced Urban Heat Islands on the planet.
http://data.giss.nasa.gov/gistemp/2005/
BTW, I don't know where you got the idea tropical Africa has warmed substantially. There has been little or no warming right across the tropics
http://data.giss.nasa.gov/gistemp/2005/2005cal_fig1.gif
Africa is the one in the middle Phillip. Well done on another ignorant comment.
anonymous, why don't you read the words above the graphic? You are looking at the 2005 anomaly, i.e. one year. The 50 year anomaly is below. There has been no significant warming in tropical Africa over the last 50 years. End of story.
BTW, what is it with AGW believers and personal abuse?
Well if it happened in 2005 it can't be true. Are't you on record as saying that you don't believe in geostrophic flow and that the greenhouse effect is caused by too much heat? I wouldn't expect you to spot ignorance under those circumstances.
Its difficult for Australians to appreciate how much energy people in very cold climates like Siberia and Alaska use. For example, vehicles are manufactured with an electric heater in the engine block, and you plug it in at night to stop the engine oil freezing. Prior to the invention of the engine block heater, vehicles were kept running 24 hours a day.
Anonymous, so you accept that there has been no significant warming in tropical Africa, and that Siberia and Alaska will have warmer UHIs than anywhere else?
No, Philip, most of the arctic data comes from automated weather stations and ship tracks. It is very difficult to build a town on sea ice. Additionally most antarctic weather stations where a warming trend is also found use automated weather stations well away from stations. Examples and distribution here:
http://www.paroscientific.com/autoweatherstation.htm
Here is my advice. Read, Think, read again if you don't understand, then comment.
The data suggest that Antarctica temperatures have not increased at all. Here is my analysis for Macuarie Island, as well as for Mawson. Both of which show no significant increase in temperatures. Feel free to view this report which says that:
“It’s hard to see a global warming signal from the mainland of Antarctica right now.”
And Climate Audit analyses Antartica data and concludes:
"IPCC AR4 has some glossy figures showing the wonders of GCMs for 6 continents, which sounds impressive until you wonder - well, wait a minute, isn’t Antarctica a continent too? And, given the theory of “polar amplification”, it should really be the first place that one looks for confirmation that the GCMs are doing a good job. Unfortunately IPCC AR4 didn’t include Antarctica in their graphics. I’m sure that it was only because they only had 2000 or so pages available to them and there wasn’t enough space for this information."
And nice picture given as well too, which shows no concrete around the weather station. Interesting that at these weather stations the temperature has not increased.
Antarctic Peninsula Jonathon. Perhaps if you did a global analysis you might have more interesting things to say.
Lose the argument, change the subject, invent facts, introduce irrelevancies, resort to personal abuse. The usual tactics of AGW believers.
http://data.giss.nasa.gov/gistemp/2005/2005cal_fig3.gif
The Peninsula is the bit that looks like a tale. As I said, read, then think. Sorry for being so off topic
The Antarctic peninsula is 2% of the continent. The other 98% is cooling. Sea ice is at record extents.
The Antartic peninsula is the only physical obstruction to the Southern Ocean's circum-planet circulation. Any changes to that circulation will be seen on the Antarctic peninsula. So the observed warming is likely caused by ocean currents changing due to PDO, increased sea ice, or something we don't yet understand.
Of interest, the warming is in the summer which indicates the cause could be increased sea ice (from a colder Antartica) changing ocean circulation.
http://64.119.172.31/awpf.pdf
Do you believe in the Coriolis force now Philip? What happened to your urban heat island effect? Don't penguins plug their cars in at night?
Round1: Melbourne, Gust 1 - Anonymous 0
Round2: Gabo Island, Gust 0 - Anonymous 0
Round3: Africa, Gust 1 - Anonymous 0
Round4: Antarctica, Gust 1 - Anonymous 0
Round5: Antarctic peninsula, Gust 1 - Anonymous 0
Round6: penguins - still undecided.
Score Update: 4-0
Melbourne? Where is the UHI effect in any of the distributions?
Now I remember what you are talking about. I told you that you can use your hand to make the water go either clockwise or anti-clockwise when it drains down the plughole despite the myth that the coriolis effect makes it go either one way or the other in either hemisphere.
I was playing a little joke on you. Giving you something to entertain yourself while mummy gives you your bath.
Jonathan, add a point for bath-time joke not got.
I think we have to update the maxim,
There are Lies, Dammed Lies and What AGW Believers Say.
And don't forget the one about OLR being heat either. That was my personal favorite.
Sigh, radiation isn't heat. It's one of the means by which heat is transferred.
I'm tired of this game. Why are AGW believers such ignorant morons? Shooting fish in barrel would be harder because fish are smarter. At least they wouldn't worry about the coriolis effect when their barrel sprung a leak and the water (arguments and facts) is draining away.
Well Philip, you are the one that said it was. Should I apply your conclusions to you? Or were you just kidding about that too?
Still waiting for the HI pattern in the warming distribution guys. No hurry.
anonymous said, I am a liar, fool, charlatan, etc.
Don't you realize you and your sort are so throughly poisoning the well that no thinking person agrees with you. You are left with the clowns in chief like Gore and Flannery to propagate your message.
Let's pretend for a moment that global warming is a real problem. That makes you 'anonymous' a climate crimiminal because you are wilfully spreading lies and misinformation. I doubt we will be hanging climate criminals from lampposts anytime soon, but you never know.
Well, perhaps you would care to restate your sea ice interhemispheric teleconnection proof against global warming here? If not we can go to the archives. I am not sure about GW one way or another, but I know from what you have said on this wesbsite that you are a) a climate skeptic and b) misinformed about most things. I think it is other people who are putting a) and b) together.
aren't all scientists skeptics? or at least shouldn't they be to some degree? You make it sound as though being a skeptic is like being a criminal, when in reality, a healthy dose of skepticism is an important part of being scientist. And please feel free to tell me how Phillip/Me are misinformed. And yes, the score is 5-0 so answers to our comments are welcome before you decide to change the subject
You declaring victory Jonathon? I think Bush has a 'mission accomplished' banner you could probably borrow if you like. Scientists are not skeptics jonathon, scientists are disinterested. And my point regarding Cowboy Philip is that after claiming that the best place on Earth to find a UHI is a large swath of Eastern Siberia (marvellous!), the assymetry in polar sea ice behaviour he claimed up until today is matched beautifully by the observed recent warming. Philip is claiming essentially that the massive decrease in Arctc sea ice is due to people plugging their cars in in Fairbanks. You really have to admire the logic.
Victory is never achieved in science. Truth through proof is.
Scientists are not skeptics jonathon, scientists are disinterested
Obviously you are not a scientist.
Indeed, scepticism is the essence of science and belief the enemy.
Are you skeptical that bananas are grown in Queensland Jonathon? Or disinterested? Skepticism is a conclusion, disinterest is an attitude. But on behalf of many of the people on this site, thank you for finally admitting that you start with a conclusion and work backwards. It is a big step, and personally I am proud of the both of you. Well done. Correlation with sea ice behaviour whenever you like.
I think you need to learn a bit more about how science works "Anonymous". As wikipedia puts it:
Scientific skepticism or rational skepticism is a scientific or practical, epistemological position in which one questions the veracity of claims lacking empirical evidence. Scientific skepticism utilizes critical thinking and attempts to oppose claims made which lack suitable evidential basis.
and please feel free to give one, just one example of how I start with a conclusion and work backwards. Because this is a complete fabrication.
A climate skeptic quoting wikipedia. That is a perfect example of you working backwards from a conclusion Jonathon. Ever heard of a dictionary? Or didn't they give you the answer you wanted?
not only have you no idea about science, but it seems you have no idea about how dictionary's work. Dictionaries lookup individual words, not methods of scientific analysis.
But lets look up the dictionary anyway: Dictionary
There are no dictionary entries for Scientific skepticism
but it suggests a link to wikipedia.
OK, to make things a bit easier for you, let me ask you this. Should readers of your web log be deeply skeptical regarding your skepticism? A simple yes/no answer, and explanation regarding the observed NH/SH temperature/sea ice assymmetry accounting for the Urban Heat Island effect will do just fine thanks.
Yes, i believe everyone should be skeptical of my findings and research results. That's science.
I have little doubt that decreases in northern hemisphere ice is due to GW, just like increases in ice in the antarctic are due to decreases in temperature
As far as UHI effect goes. This the scientific literature has not been looked at enough. Della-Marta et. al (2004) say that
The influence of urbanisation is also complicated by poor exposure at many observation sites, such as being located in or near a bituminised carpark. Consequently, it remains unclear how much urban warming is really evident at the annual time-scale for small towns"
and later
"And even though a large subjective assessment of the likelihood of urban contamination within these records has been made, further work needs to be undertaken to better understand the relative contribution of urban warming to the temperature records of small Australian towns"
Previous research had labeled urban weather stations as stations situated within a community of 100,000+ inhabitants, irrespective of the conditions or nature of the station, which what I and, whatts up with that, claim, it completly inadequate.
skeptical of your skepticism Jonathon, not your research and results. You said yourself that skepticism was a position. Please try again.
Y or N.
Jonathan, pearls before swine.
And, I expect a biblical quotation will get me labelled as a creationist.
BTW, I don't accept that melting artic polar ice is evidence of global warming. It's evidence, perhaps, of Arctic warming. Although, particulate pollution (black carbon) seems to be a plausible explanation.
The elephant in the room of the whole GW debate is where is the evidence of global warming? The statistical average of a far from a number of far from random locations just shows there is local warming at many locations. It's not evidence for global warming.
Where we should be seeing evidence for global warming for example in the sea surface temperatures. It's just not there.
http://earth.rice.edu/mtpe/hydro/
hydrosphere/latest/avhrr_sst/avhrr_ssta.html
should readers be skeptical of my skepticism of GW? WTF? You are asking me should readers question my skepticity? A double negative! So you asking me if readers should doubt the scientific principle of healthy skepticism which I uphold?
IF they were skeptic of my skepticism, then that would make them think me to be a "believer". So you are asking me should readers think that I am a believer in man induced GW. You are going around in circles my man.
And re ice melt and GW. I am sorry I meant local warming, not GW. And even that is highly debatable.
Seriosly? Who cares!
Are there some things that as a scientist you can't be skeptical about? Or can it be applied universally and therefore self referentially? Y/N?
yes of course there are some things a scientists need not be skeptical about. By the definition above, when there is not a lack of empirical or conflicting evidence.
Bananas grow in Queensland for want of a better example.
So I shouldn't be skeptical about you falsifying your data? Just a hypothetical, don't go off the rails.
well I take that with great pride if you are skeptical about me falsifying my data, because that means that it so amazing that one thinks that it could be made up.
Of course you can be skeptical about that. Skepticism is great in science. But give me your email address and I can send you the raw data. Even better, email the Australian Bureau of Meteorology for the data and they can send it out to you, it only costs $30. Then do the analysis. Wa-la!
It's a hypothetical Jonathon, if you don't like the word 'your' replace it with 'someone else's'. Should I be skeptical about theirs?
yes be skeptcal about mine, and be skeptical about others. I healthy form of skepticism is great. If you are skeptical, take a look at their methodology and see if there any loop holes.
Once you've done the research into their findings and methodology if you can't find any loop holes then there is no need to be skeptical.
So you should be skeptical about everyone else's research?
to a certain degree yes. where is this going?
A certain degree of skepticism? 0%? 30%? 100%? Or does it depend on context? I'm sure that people interested in skepticism as a scientifically objective mode of rational enquiry will be very interested to hear.
you can't put a figure on skepticism. But as I said above:
Scientific skepticism or rational skepticism is a scientific or practical, epistemological position in which one questions the veracity of claims lacking empirical evidence. Scientific skepticism utilizes critical thinking and attempts to oppose claims made which lack suitable evidential basis.
And climate science, being an immature science, deserves a reasonable amount of skepticism, especially as there is a lac of empirical evidence and many contradictory research results.
So if there is no way to put a figure on skepticism, there is no way for scientists to be able to be uniformly sckeptical? They would all be skeptical in their own way?
hmm we are going in circles. Can you please let me know what your point is?
And yes, some scientists are more skeptical than others. It all depends on their perceived value of the empirical evidence at hand.
So if I was analysing your data and I was skeptical that the BOM forgot to change the times for DST, even though they said they did, can I go ahead and change them to the correct values?
time based temperatures that the BOM give are based on local times and therefore include day light savings.
despite day light savings issues, remember that the analysis is based on relative temperatures to that particular weather station for certain months of the year. In other words, 3pm one day is compared to 3pm another day only within the same month. Of course DLS doesn't occur at the end of the month, however I have looked at month to month differences and seasonal differences for certain states that have differing DSL rules.
You are missing the point. Can I change it, or any other dataset that I have compelling evidence that I should be skeptical about?
if you have logical reason to change it and you mention that in your methodology, then yes you can change it. Adjustments are made all the time
And what if you receive your dataset from someone who made the changes but forgot to tell you about it?
well i guess then you have a problem
And how will skepticism tell you which is the correct dataset?
I'm not skeptic about the dataset at all. The ABOM have a very professional service and their datasets are pristine. Their data comes with an 8 page report which tells you about their accuracies and the various variables.
I don't have any skepticism about th accuracy of the dataset.
Somebody needs to buy a dictionary and look up 'scepticism' versus 'belief' and then 'trust'.
For example, Jonathan may say the moon is made out of green cheese and he can prove it because he has a piece of green cheese that has 'made on the moon' stamped on the bottom.
I am sceptical about the moon being made of green cheese, even though I trust Jonathan is telling the truth about his piece of green cheese. However, he believes his piece of green cheese originates from the moon and in my view is not showing sufficient scepticism about its provenance.
So you don't have any skepticism about your dataset, but you do have skepticism about other peoples datasets. Seems a rather arbitrary decision to make? Or should you be a) skeptical about everyones data or b) not skeptical about everyones data
Thanks again for your input Philip. Gosh those photons are hot today!
in general I'm not skeptical about anyone's dataset. But their analysis of the data is the thing t be skeptical about.
Analysis. OK, you use excel right? I'm sure you know about the excel bug
http://it.slashdot.org/article.pl?sid=07/09/24/2339203&from=rss
So how many other bugs are out there? Why is data separate to analysis in terms of skepticism?
well data is easily obtainable from just about anyone, and most datasets are fine in regards to their accuracy. Get 20 people together to analyse the dataset and you'll get 20 different results. Not because thats how it works, but because most people who are not statisticians do not apply to correct methods of statistics to the data and hence get wrong results.
Well, as a statistician you will be able to answer this. All datasets have an experimental and analytical error component that when combined will have a residual from theoretical prediction which is not normally distributed. Correct?
well all measurements have an experimental error, not technically the dataset. Analytical error is something else, and the error might or might not be normally distributed, hence the need for statistical tests to prove or disprove significance.
When is analytical error ever normally distributed? Give me one example.
by analytical error I mean error based on misuse of statistical methodology, its distribution is obviously unknown
Well, you must be the only statistician on earth who defines it that way. Most people define it as resulting from faults in the experimental design, due say to processes like an urban heat island. Is that Gaussian?
I think we are talking about the same thing. the distribution of experimental error, like faults in the experiment and design and like UHI are not by definition distributed in one particular way. it is obviously different for different variables.
it is obviously different for different variables.
So never purely random with a normal distribution then?
i guess, why?
Well, if the combination of experimental and analytical is never normally distributed that means that given the noisiness of atmospheric data any incomplete experimental design will lead to significant and potentially correlated residuals between prediction and observation. Now as a skeptic what would you make of these residuals?
well thats why one should use statistical tests of significance to prove whether a relationship exists due to a certain factor or if it exists due to experimental error/natural variation or noise.
So where is that healthy dose of skepticism now?
I have a healthy dose of skepticism, mainly over statistical analysis. Eg, the CSIRO claiming how much water has decreased in southern and eastern australia, in part due to global warming since 1950, when analysis shows an increase in rainfall in the last 50 years compared to the 50 before that.
Some states showed a significant increase, whilst others showed that the only difference was due to random variation and noise.
This is a blatant misuse of the data and the statistical tests in their analysis was nowhere to be found.
I am skeptical of their findings because of the lack of empirical statistically sound evidence.
I am not skeptical of the data.
But you said that skepticism was a methodology of reconciling contradictory evidence given the fact that climate science is a young science with many unknowns. You are now saying something else, ie a lack of evidence. What would a skeptic make of that? Should they be skeptical of your skepticism?
No I said this about skepticism:
"Scientific skepticism or rational skepticism is a scientific or practical, epistemological position in which one questions the veracity of claims lacking empirical evidence. Scientific skepticism utilizes critical thinking and attempts to oppose claims made which lack suitable evidential basis."
You ask, what would a skeptic think of that? I presume you mean a "climate skeptic" or better, someone who doesn't believe in man made GW. I am not a skeptic by that terrible definition, however I am skeptical of man made global warming due to lack of empirical evidence.
"And climate science, being an immature science, deserves a reasonable amount of skepticism, especially as there is a lac of empirical evidence and many contradictory research results."
And we have two here from Jonathon regarding skepticism
yes, i agree with both those 2 comments. Climate science is an immature science so should be dealt with a reasonable deal of healthy skepticism, which has defined by the previous one occurs when there is a lack of empirical evidence.
I'm not sure what you are trying to say.
Well, if you don't see your internal contradiction I need to spell it out from example. As a skeptic, please confirm for me that the world is not a figment of you own imagination. List the empirical evidence to the contrary and show me how this premise leads to contradiction. Do you live in the real world?
well there is for starters not one piece of empirical experiemental evidence that links CO2 greenhouse gases with GW. Junk science has a $125k prize if you come up with it.
That said, it is of course very hard to come up with experimental evidence for GW. The main evidence for man induced GW comes fr climate models, which, well, lol.
Almost every week new reports are coming out blaming different things on GW. Hardly convincing proof.
So are you saying that CO2 does not selectively absorb outgoing long wave radiation?
no of course not, but there is no experiemental evidence to prove how much of a difference it makes.
Are you saying that you don't believe in the Stephan Boltzmann equation?
no
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