Another round of tedious correction of contrarian disinformation in The Canberra Times. In response to an earlier letter, I wrote this piece which appeared in the print edition of 7 October:
Anthony Moore (Letters, 3 October) claims that satellite and land-based thermometer data show no warming over the past decade. In terms of climate temperature trends, this is not just incorrect; it ignores much more important parts of the picture.
To over-simplify, the word “climate” means the long-term average of the weather, typically over periods of 30 years or more. Annual averages in temperature are dominated by large short-term variations including cycles like El Niño. So-called “sceptics” (who seem to demonstrate a remarkable lack of genuine scepticism) like to talk about “the last decade” because they can start with a huge spike in the annual average (the 1998 El Niño) and end at a low point (the recent La Niña). This says nothing about the underlying climate trend; for that you need to look at long term averages. Look at a graph showing the 30-year average temperature: it’s been steadily increasing – in fact, accelerating – since the 1970s.
The big picture is very clear. The planet has been in energy imbalance since the 1970s: the amount of energy leaving the Earth is less than the incoming energy from the Sun. The planet as a whole is heating up, due mainly to the increase in CO2 and methane, and the energy imbalance is growing. Almost all of this heating has been in the oceans; land and atmosphere heating has been a tiny part of the picture so far.
Matt Andrews
This then attracted a response on 9 October from one of the regular peddlers of the usual ill-informed soundbites:
Matt Andrews’ response (Letters, October 7) to Anthony Moore (Letters, October 3) beggars belief.
The graph on which alarmists have consistently made their case for warming is the Global Temperature Land-Ocean Index which shows Annual Means and 5-Year Means from 1880 to 2000. And now Matt wants to move to 30-year averages to capture the bigger picture – from 1970.
That should give him just one data point!
Then he accuses sceptics of using the 1998 El Nino spike to demonstrate cooling.
Rubbish! Serious sceptics cull that spike from their data and demonstrate cooling from 2001 to the present.
And, like Barrie Smillie some time back, Matt completely misses the point.
This is not about the planet having warmed, which it has since coming out of the Little Ice Age in the mid-19th century, but whether that warming is driven by CO2.
And a planet that has had two prolonged cooling periods (1940-60 and 2001-09 and continuing) while CO2 has been rising, would suggest that CO2 is not the cause. Matt is doing the fast strokes.
Aert Driessen, McKellar
I then responded with this:
Aert Driessen (Letters, 9 October) is having trouble with 30-year moving averages of global temperature, so let me clarify: using the highest quality index, NASA’s GISS, if we use the average of the 30 years of temperatures that ended in 1975 as a starting point, we can see that for each and every year since, the 30-year average that ends at that year is a little bit warmer.
It shows a steady inexorable increase – the long-term trend we call “global warming”. The same pattern is clear in the 30-year averages of the other main index, from Hadley Climate Centre in the UK.
Taking a step back, satellite measurements show that the amount of energy received by the Earth is greater than the amount of energy that is leaving: the planet is in energy imbalance, and thus is heating up. It’s been in that state since the 1970s, and the imbalance is growing.
Matt Andrews
#1 by Tamas Calderwood on October 10, 2009 - 5:46 pm
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Matt – you say that “the amount of energy leaving the Earth is less than the incoming energy from the Sun”
However, if the planet has not been warming for 10 years then your argument would violate the first law of thermodynamics – ie; the conservation of energy principle.
Please explain.
Tamas
#2 by matt on October 10, 2009 - 11:25 pm
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Certainly. The explanation is that the planet has been warming for the last 10 years.
As I’ve been trying to explain, short term movements in land and atmosphere surface temperatures are a tiny part of the whole picture. Land and atmosphere heating has absorbed around 5% of the energy imbalance; the other 95% has been in the oceans.
Beyond that, we need to talk about short term variability vs long term trend; the spikes and dips over the last decade do not actually constitute systemic cooling at all. They are completely consistent with the type of natural short term variability that we’ve seen in past decades, superimposed over the underlying warming trend.
One article that might help to clarify this is Embarrassing Questions. It’s a long read, but the discussion of natural variability over varying timescales in the later part of the article is well put.
Back to the global energy imbalance: Skeptical Science has a series of articles which illustrate the situation in a reasonably accessible way:
Measuring Earth’s energy imbalance (read the whole article, but in particular, absorb what figure 3 – and figure 4 – mean).
How we know global warming is still happening
How we know global warming is happening, Part 2
Did global warming stop in 1998?
#3 by Tamas Calderwood on October 11, 2009 - 12:44 pm
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Sorry Matt – I don’t accept that the world has warmed for the past 10 years. The Argo buoy program shows ocean cooling and the satellites show no warming of the atmosphere.
Even the BBC now admits this:
http://news.bbc.co.uk/2/hi/science/nature/8299079.stm
#4 by matt on October 15, 2009 - 10:50 pm
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Hi Tamas, sorry for the long delay in replying. Busy times.
Did you actually read the articles I linked to?
If you really want to quibble about whether the temperature record of the last ten years shows warming, you’d better stump up some kind of convincing evidence. Because it seems to me that Hadley, GISS, and even the far more indirect measurements of UAH all show warming over the last ten years.
But, as discussed in those articles, that kind of short timeframe, looking only at atmospheric temperatures, is a really, really small part of the big picture. Please, read the articles properly if you want to understand what’s happening with the climate. Or, for a less daunting summary, see Empirical evidence that humans are causing global warming.
It’s a widely circulated “fact” among denialists that the Argo network shows ocean cooling.
In fact, however, like so many other “facts” in those circles, it’s a cherry-pick which appears to be essentially incorrect:
(from How we know global warming is still happening, which discusses the issue further.)
As an aside, you’re happy to avoid Adam Rope’s point (that all the major scientific institutions of the world support the mainstream view) by calling it an “appeal to authority”, but yet…?
With this article by Paul Hudson, the BBC has disgraced itself by letting this one get released without proper checking. It has come under fire for the remarkably poor research quality of this piece. The article is incorrect on several major points. See, for instance, this response from Joseph Romm.
#5 by Tamas Calderwood on October 18, 2009 - 1:31 pm
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Matt,
Yes, I read or browse most of the links you point me to.
The UAH temperature data is interesting. A linear regression from January 1998 shows a –0.05C cooling trend. From January 1999 you get a 0.11C warming trend. I suppose both data points are distorted by the 1998 el nino peak and the subsequent la nina drop in temperature straight afterwards.
Since 2001 there is a 0.1C cooling trend.
The point of all this is that Earth can hardly be said to be in “energy imbalance” since the 1970’s. There is no imbalance right now. For the past 30 years there was a slight warming trend but the 30 years before that had a slight cooling trend.
Also – what caused the rapid warming from ~1910 – 1945? CO2 emissions were far lower back then but the warming was just as rapid as that observed in the past 30 years.
All up Earth is only 0.6C warmer than it was in 1900. Why is that so dangerous? Surely you do not expect the temperature to remain perfectly constant?
All the problems from global warming are predicted. None has been observed. And the BBC rightly points out that the flat temperature observations of the past decade are quite unexpected.
#6 by matt on October 22, 2009 - 5:14 pm
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Hi Tamas, you say that…
…but how is it, then, that you appear not to have grasped several of the basic aspects of the situation?
Firstly, you ask about the warming in the early part of the 20th century. Please take some time to peruse The CO2/Temperature correlation over the 20th Century. In particular, you can see the gory details of what unfolded through the 20th century in Figure 2 of that article. Basically, around 1910 there was an unusually cool period due to volcanic eruption. The temperature then rose once those short-term aerosols disappeared, but until around 1940 the rise in greenhouse gas concentrations – the light blue line – was much faster than the increase in reflective tropospheric aerosols (which have a cooling effect) – the light blue line. Thereafter, aerosols grew rapidly, causing the plateau in temperatures after WWII until around 1970, when greenhouse gases began to rise much more rapidly than aerosols again.
Secondly, you appear to still be citing temperature data over very short timeframes. This is a basic, basic misunderstanding. Talking about a temperature trend since 2001, as if it were some kind of indication of the underlying climate trend, is akin to saying that “it cooled from 22 September to 27 September, so the spring warming is not happening”. Natural variation – the wild ups and downs caused by assorted factors including El Nino – completely swamps the underlying warming trend if you look at just a few years like this.
You can get a grip on this visually by looking at the main graph in Uncertainty, noise and the art of model-data comparison. As you can see, the blue lines, which are 8-year trend lines, have strongly varying slopes over the last several decades, and some periods where they are negative in slope, but the overall underlying trend is clearly positive (warming). This is the way the climate is – talking about annual averages, or even a period of ten years or so, is barely useful in itself. What’s useful is the long term trend – the underlying signal. To get that, you really need 15 or 20 years, or preferably 30 years, which is, after all, one of the standard definitions of the word “climate” – the average of the weather over a period of at least 30 years.
And again, I’d point you to Embarrassing Questions – the series of graphs at the end of the article demonstrate it quite clearly. A warming pause? is also worth reading.
Thirdly, you appear to be saying that a short term UAH trend leads you to the conclusion that “there is no [energy] imbalance right now”. That’s a misunderstanding of the big picture: atmospheric temperature is a tiny part of the energy equation of the Earth; the energy imbalance has been measured directly (as you would see if you read the Measuring Earth’s energy imbalance article again); and, as mentioned earlier, short term trends using low quality data don’t tell you much of value about the atmospheric warming trend anyway.
#7 by Tamas Calderwood on November 3, 2009 - 9:52 am
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Matt – been very busy and will continue to be for a couple more weeks. However, just want to say that the stuff about aerosols cooling the earth vs greenhouse gases warming it is pure conjecture. There is no actual evidence that this is what caused the temperature fluctuations.
There are so many other possible natural factors (including the big one – the Sun) that account for the various warming / cooling phases we have seen in the past 100 years.
Also, 2001 – present is not a short time frame. The AGW theory says more CO2=more warmth. Well, we’ve got more CO2 so where is the warming? What has been cooling the earth for the past ~10 years?
I keep coming back to this but if we can’t explain past variability (Roman warming, medieval warming, dark ages, little ice age, etc) how can we now suddenly say the tiny amount of warming over the past 100 years is because of man-made CO2?
Anyway, not a single person has died because of global warming. Surely in this world with billions living in poverty we have more pressing priorities.
Please excuse me if my postings are light in the next week or two. Work is damn busy.
Tamas.
#8 by matt on November 16, 2009 - 11:20 pm
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Hi Tamas,
Where do you get that impression from? There is historical data on tropospheric aerosols, in fact, which can be combined with basic physics to arrive at quite a good estimate of the associated forcings over the last century. Clearly it’s not completely precise, but the level of confidence is quite good on this aspect – hardly “pure conjecture”. See this NASA page for some details on the tropospheric aerosol data. There’s plenty more technical information on this if you dig for it.
This really is one of the top denial memes, and one that I’m afraid I’ve found deniers to absolutely refuse to understand.
Short answer: as a global system, the planet has indeed continued to warm over this period; and the surface atmospheric temperature is only a tiny part of this energy flow, and is subject to a whole lot of natural fluctuation. You say the period since 2001 is “not a short time frame” – based on what? This is not a seat-of-the-pants thing; there are good statistical reasons for needing a longer time frame than one decade for data with a level of short term variation like the global temperature record. This is why a common definition of the word “climate” is “the average of the weather over at least 30 years”.
To illustrate the statistical point, see the recent blind test by Associated Press: “The AP sent expert statisticians NOAA’s year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.
Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.”
Please re-read the last four paragraphs of my most recent comment in this thread, and especially the articles I link to in them, as you appear not to have understood this material yet.
Erm… because that’s what a large body of evidence indicates. Perhaps reading this will help.
Big claim. How exactly do you reconcile that against the 35,000 that died in the 2003 European heatwave, the thousands that died in the 2006 European heatwave, and indeed the horror of Darfur, of which a major cause is the water crisis there, linked to the rise in temperatures in the Indian Ocean?
The worst impacts of climate change over this century are expected to be in poor countries, particularly in Africa. Darfur is, if anything, likely to be repeated many times over in sub-Saharan Africa. To ignore those impacts – particularly given the very strong scientific body of evidence which underlies those projections – would be an act of spectacular callousness.
Likewise… apologies for the delay in replying.
#9 by Tamas Calderwood on November 24, 2009 - 8:20 pm
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G’day Matt,
– on the aerosols I have a very good source (recently revealed from the CRU emails).
Here is Mike McCraken writing to Phil Jones, head of the CRU:
“Your prediction for 2009 is very interesting…and I would expect the analysis you have done is correct. But, I have one nagging question, and that is how much SO2/sulfate is being generated by the rising emissions from China and India…. While I understand there are efforts to get much better inventories of CO2 emissions from these nations, when I asked a US EPA representative if their efforts were going to also inventory SO2 emissions (amount and height of emission), I was told they were not. So, it seems, the scientific uncertainty generated by not having good data from the mid-20th century is going to be repeated in the early 21st century ”
Pretty interesting.
Now, on the lack of warmth since 1998. Here’s Tim Flannery: “We’re dealing with an incomplete understanding of the way the earth system works… When we come to the last few years when we haven’t seen a continuation of that (warming) trend we don’t understand all of the factors that create earth’s climate…So when the computer modelling and the real world data disagree you’ve got a very interesting problem… Sure for the last 10 years we’ve gone through a slight cooling trend.”
And Phil Jones way back in 2005: ““The scientific community would come down on me in no uncertain terms if I said the world had cooled from 1998. OK it has but it is only seven years of data and it isn’t statistically significant”.
Well, it is now almost 2010 and we’ve had nearly 12 years of cooling since 1998. At what point can we say the cooling is significant?
These CRU emails and data are pretty damning mate. Why are these guys suppressing dissent, deleting data, questioning the lack of warming and admitting they don’t know what’s happening in the climate system, while at the same time they are ramping up the fear-factor?
Even George Monbiot now agrees this is all “a major blow”.
What do you think?
#10 by Steve O'Connor on December 7, 2009 - 12:24 pm
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tamas, are you for real? are you being paid to come up with this crap?
#11 by matt on December 8, 2009 - 2:39 pm
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Tamas, as you should well know, choosing 1998 as a starting point – the strongest El Nino event in a century – is ludicrous. Go and learn some basic statistics… you don’t assess trends in a time series like global temperature (where there is a high level of internal variability) by starting from a reference point of one of the most extreme spikes in the record.
That’s why Phil Jones says “it isn’t statistically significant”.
I quote from my previous post (since you didn’t seem to understand the point):
Want to understand the big picture of the temperature trend? Here’s your reading for the next ten minutes: Riddle Me This.
The disinformation around the stolen CRU emails is damning, yes – damning of the willingness of climate deniers to focus on cherry-picked quotes, while completely failing to understand the scientific basis for the discussion, and in general ignoring the big picture of the evidence.
In fact, the only substantial indication of scientific fraud to come to light in the stolen CRU emails is on the part of anti-AGW favourites Willie Soon, Sallie Baliunas and Chris de Freitas.
Given the pervasive and shameless manipulation of data, cherry picking and trumpeting of outright falsehoods which we’ve seen from climate deniers over the years, the CRU affair would be pretty damn funny – if the consequences of delay and inaction were not so serious.
For a touch of sanity on all this, I recommend What happened to the evidence for man-made global warming?
#12 by Tamas Calderwood on December 9, 2009 - 4:21 pm
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Steve – Yes, I am for real. No, I am not being paid to argue my case. I do this all pro bono. Do you have any response to my actual arguments, by the way?
Matt – Thanks for your suggestion but I already took statistics at university and there is no need to be rude.
I agree that the cooling trend from 1998 is not statistically significant given the variability in the temperature record. However it is still a cooling trend and it raises the following questions:
Why was the 1998 El Nino peak so warm?
Why have subsequent El Nino’s not been as warm. As Kevin Trenberth asks in his leaked emails “Where did the heat go?”
I also think you underestimate the effect that the leaked emails and data will have on this debate. There is no denying that it is now big news and people are asking a lot of questions about the way this “science” is conducted. It also shows the appalling state of the CRU’s temperature records – those records that they haven’t deleted.
You refer to the “big picture of the evidence”. Well, CRU is half of this big picture (NASA GISS is the other half) and CRU has been shown to be dodgy.
As for the “shameless manipulation of data, cherry picking and trumpeting of outright falsehoods”, well I say that is the definition of how the global warming alarmists act.
They erased the medieval warm period and now the CRU leaks show how.
They stopped others from being published in the peer-reviewed literature.
They have refused to release their data in an outrageous breach of the protocols of openess in science.
Yet you say what has been revealed is damning of the sceptics? How do you come to that conclusion?
#13 by matt on December 9, 2009 - 5:21 pm
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Tamas, thanks for the response, and I apologise if I was rude. I am having trouble reconciling these two statements:
…and…
Before we get to the other issues you raise, please read Riddle me this … and then tell me where your statistical argument is for selecting a 1998 starting point (in other words, arbitrarily removing the data before 1998).
#14 by luke on December 9, 2009 - 8:43 pm
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so Matt can you answer his question about the accusations against CRU and GISS. I am now interested lol
“As for the “shameless manipulation of data, cherry picking and trumpeting of outright falsehoods”, well I say that is the definition of how the global warming alarmists act.
They erased the medieval warm period and now the CRU leaks show how.
They stopped others from being published in the peer-reviewed literature.
They have refused to release their data in an outrageous breach of the protocols of openess in science.
Yet you say what has been revealed is damning of the sceptics? How do you come to that conclusion?”
These accusations have not been denied even by the CRU scientists.
Personally let me say i am all for looking after the environment. I agree we need to do something even god forbid a carbon trading scheme. But this whole thing stinks of a deeper political agenda of which I have a few crack pot theories. For one carbon tax is a ridiculous name, we are all carbon based life forms so are we trying to tax humanity??? and have a look at where the majority of carbon comes from….you will find that interesting. For starters it should be a pollution tax or scheme, and alternative energy investment. NOT because of global warming but rather due to the fact we have to cut down our living standards and learn to share the earths recources. Even if we went all green and on solar panels etc there is only a certain amount of raw material available etc. So in actual fact we need to live simpler lives, maybe only one car instead of two…oh no i said it hahah why dont people do that …that would cut down our pollution levels etc. or even not have lights on after dark lol no more need for power stations…i am being hypothetical but i am right. Why don’t we all be more generous to begin with. Because we are all selfish bastards and we think we cant do anything…so that actual problem is humanity itself…mmm wonder who else says that…look up the club of rome and find there data files. Anyway bottom line is if you, matt and tamas decided to put our money towards making an orphange in our life time we def could. There would be sacrifices but thats what you may have to do to see maybe up to 1000 kids live. So in reality we dont want to change because the issue is one that goes back to our own selfishness…..in reality a carbon trading scheme is may help a little in the planet sharing resources if it is done in the right way but in actual truth the problem is us…so whos up for stuff buying a house and build an orpanage to save 1000 kids, or selling there car and walking or not turning off there lights at night and etc….oh not you thought so…we are all hypocrites.
Secondly this smell of a huge political grasp for power. This will be the first global ets or tax whatever you want to call it. Lets put it out there, its gonna happen. But who wants the power and why??? ill leave that for you to think about and maybe research into a bit. Also look at Rudds scheme, who sets the value of life itself(carbon) is it fairt tale rudd or is it the UN or some other body….that is the question we all should be asking… as aussies.
#15 by luke on December 9, 2009 - 8:51 pm
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oh yeah and another things what happens to ice when it melts??? it cools the water surrounding it….is that why the oceans seam colder now….(i surf an i swear the water is colder…maybe we are all looking at this through blind eyes.) If i tell you its cold, you will think about it. If i tell you again then you will think about it some more. Eventually if i tell you enough you may begin to believe it…sound like whats the media is doing now…wish they’d all shut up and present some scientific facts…not talking to you guys i am more annoyed at the media, we all just want cold hard facts but that seems to be impossible with all the agenda and egos going around in the science world lol
#16 by Tamas Calderwood on December 12, 2009 - 1:52 pm
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Matt – I read the ‘riddle me this’ piece.
Um, so how is the 0.38C warming trend over the past 30 years consistent with your claim of 0.2C warming per decade?
And by the way, none of the models expected the world to stop warming this decade. And it has stopped warming. No matter what you say you cannot get around that fact.
I have done a linear regression on the UAH data, again, and here is what the trend is from October 2009 back to October in the following years:
2006 -0.11
2005 -0.16
2004 -0.20
2003 -0.14
2002 -0.13
2001 -0.15
2000 -0.07
1999 0.05
1998 0.11
1997 -0.04
1996 0.04
1995 0.12
Those trends are basically flat or negative all the way back to the mid 1990’s. How can that be when we’ve had record human CO2 production since then?
And I think we can categorically state that NASA GISS and the CRU HadCRUT data have been adjusted to suit the views of the global warming alarmists. The leaked emails and particularly the leaked computer code from CRU confirm this. That is why I only trust the satellite data.
This is turning into the biggest scientific scandal in history Matt. I am outraged that we have been lied to like this. Why aren’t you?
#17 by diessoli on January 6, 2010 - 10:56 am
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How have you done your regression: from 10/1995 to 10/2009, 10/1996 to 10/2009, etc?
Can you actually quantify how large the error for each of these “trends” is?
Have a look at these two plots of UAH data + linear regression:
The last 120 months show a positive trend,
http://www.woodfortrees.org/plot/uah/last:120/mean:12/plot/uah/last:120/trend
The last 100 a negative:
http://www.woodfortrees.org/plot/uah/last:100/mean:12/plot/uah/last:100/trend
Does that mean that the trend suddenly reversed?
Of course not. But it makes it obvious that there is no point in looking at such short term intervals. The noise is too large to see a statistically meaningful signal.
Can you provide some evidence for this please? I’ve seen nothing that would support this point of view.
My outrage goes towards those that take quotes out of context and use this to dream up some conspiracy, just so that they don’t have to have an actual fact-based discussion.
D.