Gust Of Hot Air
Gust of Hot Air is a blog outlining my own statistical analysis of Australian Weather. I am Jonathan Lowe, and have completed by Bsc(hons) in statistical analysis as well as my Master of Science. I have done 2 years of my PhD
There is a lot of statistical information regarding climate change and I intend to provide statistical analysis into the area to prove if the recent well advertised rise in temperature is at all statistically significant. Results will be uploaded here on a regular basis
Analysis of Australian Temperature - Part 1
Fri 03 Apr 2009 - 12:33 PM
Website: Gust Of Hot Air
Australian temperatures are on the increase, there is little doubt about that. Maximum and minimum temperatures have risen by about 0.7 degrees in the last 100 years. Our analysis will look not only at maximum and minimum temperatures, but also at time based temperatures, which we previously argued
are a better more consistent representation for temperature analysis.
Using 21 weather stations around Australia that have accurate and consitant time based temperature data from 1950 onwards, we also found that the maximum and minimum temperatures have significantly increased in the last 50 years. This is shown below. Click on them for a larger graph.
You should note a couple of things. Firstly, the maximum temperature has increased since 1950 at a rate of 1.5 degrees which is larger than normal. This is for a couple of different reasons. One is that temperature has warmed up quicker in the last 50 years than the 50 before that, and secondly, because we have had to use some urban weather station in our analysis which is not normally used because of the heat island effect. Thus the increase is greater than normal.
But that shouldn't worry us or hinder any analysis that we undertake. Secondly you will notice that the minimum temperature has increased at a rate to what was expected or at a lower rate than the maximum temperature. It is still a significant increase, although there seems to be no major changes in the temperature since around 1972. Before this we saw mostly negative anomalies, and after positive.
Either way, both maximum and minimum temperature are shown to have increased significantly since 1950 as expected.
So what about time based temperature? Well as shown below we have 8 time based temperature since 1950 for Midnight, 3am, 6am, 9am, Noon, 3pm, 6pm and 9pm. It must be noted that for some reason the amount of data for 9pm is less than the other time variables.
There are many things that we can talk about with regards to the above graphs. Readers will first note that night time temperatures (Midnight, 3am, 6am) show little increase in temperature. In fact, they average just 0.43, 0.26 and 0.28 degree increase in temperature per 100 years. This is a lot lower than the expected, which clearly indicates that night time temperatures in Australia are only increasing a very small amount.
But how can this be when the minimum temperature is shown to be increasing a lot more? Well the answer is simple and surprising to many, in that, the minimum temperature more often than not occurs during the day. Basically, as soon as the sun sets, the temperature decreases over night. When the sun rises it starts to heat up the atmosphere, and only after 30 mins to an hour after sunrise to we fall to a minimum and the temperature starts to increase again for the day.
Hence, the minimum temperature has little to do with night time temperature and is a lot more influenced by the sun and cloud cover.
Readers will also note the sudden increase in temperature at 9am, noon and 3pm. Which then starts to fade a way a little from 6pm onwards. This is highlighted in the graph below:
So it is clear that temperatures in the middle of the day have increased at a greater rate than temperature outside this time. What would cause this? It is also clear that the maximum (which generally occurs around 3pm depending on the season), and also the minimum (which generally occurs around 6am to 9am depending on the season) are highly influenced by the increase in temperature in the middle of the day.
This graph alone strongly suggests that analysis of maximum and minimum temperatures solely is not an accurate way to measure temperature. A better method would be to take the average of each of the times to come up with an average temperature increase since 1950.
Currently, climate change analysis simply averages the maximum and minimum temperatures to come to a conclusion that the world has increased by 0.7-1.0 degrees over the past 100 years. With our data, this equates to 1.17 degree increase per 100 years. However if we average all of the time based temperatures, which no doubt, would be a more accurate way of measuring temperature over time, we find an average increase of only 0.66 degree per 100 years. This is shown below:
Hence we can conclude that 44% (1 - 0.66/1.17) of all increase in temperature in Australia since 1950 can be accounted for, simply by a better mathematical method of measuring temperature!
We've just reduced the amount of temperature increase that Australia has seen, simply by looking closer to the data and analysing it in more depth. But we are going to get a lot more in depth that this. And that will have to wait till part 2
Melbourne Stage 4 Restrictions
Thu 02 Apr 2009 - 12:26 PM
Website: Gust Of Hot Air
Melbourne should now be in stage 4 restrictions for water usage, which means that watering the garden and washing the car is not allowed at all.
The trigger point for stage 4 restrictions is 29.3 percent. This was hit on the 30th of March, and already 2 days later, Melbourne's water storage levels are now at 29.1 percent.
The Brumby government said that they will stay on stage 3a till at least November. Water minister, Tim Holding said that
``We are not using trigger points because we need to take into account not only the level of water in the storages but the amount of demand there is on those storages,''
Brumby Government water minister Tim Holding said the mixture of 3a restrictions and the Target 155 water saving campaign meant metropolitan users were already held to a high standard.
It seems to me, that the only reason why we are not on stage 4 restrictions is that if we go there, then it is clear that the Brumby government's "Target 155" scheme was a failure.
With the population increasing all the time in Melbourne, and no extra water storages becoming available, it is clear that the Target 155 scheme will always inevitably be a failure.
Travelling, Working and Analysing Weather
Mon 30 Mar 2009 - 12:46 PM
Website: Gust Of Hot Air
It's been a long while since I've reported any statistical analysis of late. In fact, I've even managed to debunk a couple of my own statistical analysis on Australia's weather. I've been travelling to Europe a couple of times, working hard in my own buiness that I have set up and of course, am continuing to analyse Australian weather data patterns.
My analysis in this area is a lot stronger than has been reported on this blog, and I intend on producing almost all of it in the next week or two. That means stay tuned for some very interesting analysis on Australain weather including full temperature, cloud, and sun analaysis.
The results are quite dramatic and will hopefully cause a big discussion point. Some of the analysis is semi-repeated from analysis that has been put out here previously, but lots of analysis, especailly at the end, will be brand new and no doubt extremly interesting to many. But to start off with, I am going to give a repost of my maximums and minimums post done almost two years ago. See you real soon!
Maximums and Minimums
The world is heating up. One thing is for sure, is that there is scientific consensus on this issue! Analysis of maximum and minimum temperature have proven it. Both have gone up significantly world wide, and also too in Australia.
The maximum is used as a measure of how hot we are getting during the day, whilst the minimum is a measure of how cold we get during the night. But are they good variables to use as a measure of average temperature?
Maximum and minimum temperatures occur at different times of the day, often by large amounts when in different seasons. Surely a better measure would be to keep the time constant and see if the temperature has increased at that (and other) specific times?
But unfortunately, there doesn't seem to be a whole lot of good data lying around for this type of analysis. A large exception to this is Australian data. Whilst there is not as many time based data as maximum and minimum data, I feel that statistical analysis on the raw data is by far more advantageous than doing statistical analysis on a statistic (which is derived from the raw data).
So why has there been no scientific analysis on time based temperatures? For me it seems very strange that we can spend billions of dollars on global warming, yet still have not done the proper statistical analysis on temperatures?
The answer is simple. There is no reason to do further analysis on temperatures. We have already proven and clearly show that maximum and minimum temperatures are increasing - quite dramatically in fact. As we said earlier, there is scientific consensus on this. The world is heating up and this is beyond doubt.
So why do more analysis on something that is crystal clear and proven beyond recognition? So, naturally, noone has.
Hence we are stuck in a scientific world where we are spending billions of dollars on what will happen when the world heats up, and what we can do about it, yet have not done a full statistical investigation about how the world is heating up.
We know why the world is heating up (Co2 emissions, right?). We know who (humans of course). We know where (the entire world, especially where there is ice). We know what (our pagan earth). We even know when (now, and the devastating effects it will have on our children's children).
But we do not know how. We only know that maximum and minimum temperatures are increasing.
But as most scientists will argue, this is plenty of evidence to prove that we are warming up during the day and at night. In fact, evidence suggests that minimum's are increasing at an even greater rate than maximum temperatures (which lead some scientists to believe in the urban heat island effect etc.).
Whilst most will say that the maximum temperature is a reasonable statistic to relate to average temperature during the day (time based temperatures is obviously better), how good does the minimum temperature relate to the average temperature at night?
Maximum temperatures occur generally when the sun is at it's hottest. Well at least when we feel it the most. Generally this is around 3pm, but changes dramatically in the different seasons and weather conditions. 3pm is almost the middle of the day. It's a little later than the middle, and maximums occur a little later than the middle due to the atmosphere warming up (by the sun). Still, we as civilians, are always interested in the maximum predicted temperature by the weather forecasters as a reference to how hot tomorrow will be.
But when looking at minimum temperatures, the issue is different. As a general rule, as soon as the sun sets we start losing heat in the atmosphere and the temperature will slowly subside. It will keep going down and down until, you guessed it, the sun warms up the atmosphere and then rises.
So the minimum temperature will occur right at the end of night time - the period shortly before light. Is the minimum temperature therefore a good representation of night temperatures? Would you think that taking the temperature at sunset would be a good representation of how hot the day is?
The answer is quite clearly no. Whilst we can suggest that maximum temperatures is a reasonable (although not fantastic) statistic when it comes to it's relation with average daytime temperatures, the minimum temperature is a terrible representation of how cold a certain night is.
This being for a couple of reasons. One; in that it is not generally the minimum temperature around the middle of the night, and two; in that it is actually influenced by the sun.
The what? the sun? How on earth can the minimum temperature be influenced by the sun?
Well it does. A warmer sun would heat up the atmosphere at a greater rate, just at the time where we would normally achieve a minimum temperature. Warmer days (thanks to a hot sun!) would result in hotter nights. Maximum and minimum temperatures are related and both are quite dependent on the strength of the sun.
So what has any of this got to do with global warming? Well, tomorrow, we will show you exactly why minimum temperatures are a poor statistic in measuring overnight temperatures and will prove the suns influence and changing behaviour over time.
In short, we will prove to you that global warming - the increase in maximum and minimum temperatures - is primarily due to increases in solar radiation.
And you don't want to miss that!
Climate change not imminent danger
Tue 16 Dec 2008 - 9:21 AM
Website: Gust Of Hot Air
Rajendra Pachauri, head of the IPCC seems to have spilled the beans
here:There is no clear evidence that global warming is an imminent danger to the world, says Rajendra Pachauri, chairman of the United Nations' Intergovernmental Panel on Climate Change.
But even so why not continue to cut emmissions even though thre is no clear evidence of danger to the world:Even so, it would be good for governments to go further with proposed cuts in greenhouse-gas emissions to deal with dire predictions made in a 2007 panel report, he told the Associated Press in an interview on Tuesday.
It would be good? so what, it doesn't really matter, but it'd be good if it happened?
Rudd to decrease emissions by how much?
Tue 16 Dec 2008 - 9:08 AM
Website: Gust Of Hot Air
Almost exactly a year ago, Kevin Rudd supported
cutting greenhouse emissions by 25 to 40%:
THE Prime Minister, Kevin Rudd, signalled his support for developed countries, including Australia, agreeing to making deep cuts in their greenhouse gas emissions in the next 12 years.
In a significant move last night the Australian delegation to the UN climate talks stated it "fully supports" the proposal that developed countries need to cut their greenhouse gas emission by 25 to 40 per cent by 2020.
But just yesterday, the Prime Minister announced a 5% reduction is his plan on cutting the deadly gas by 2020. So what does 5% actually mean? Bob Brown and the Greens for example, want a 100% reduction.
Well Australa's CO2 emmisions are currently at 326,000 thousand metric tonnes. Which is about 1.2% of the worlds.
If we assume that CO2 has caused 100% of the 0.7 degre increase that we have seen over the past 100 years (extremly unlikely - even the IPCC don't perscribe to this, but still - for interests sake), then australia cutting greenshouse gasses by 5% will result in a decrease of
0.00042 degrees per 100 years, or
0.0000042 degree decrease per year.
Well done Kevid Rudd!!