The Pacific Decadal Oscillation and Australia - plus more

Here is the article about the Pacific Decadal Oscillation, with particular reference to Australia. I'll warn you in advance - it's long, a bit meandering, probably could do with more illustrations, and not a complete guide to everything. That's my excuses out of the way. I figure I've spent enough time on it so here it is. Feel free to add what you know and correct what I don't :)

In the previous article, I referred to some comments by a contributor, trying to argue that Australia's record heat of the 2012-13 summer was caused by a (non-existent) spike in the PDO index, or was an advance reaction to a spike that had not yet appeared. His comments were not easy to follow. Thing is, the PDO index wasn't positive during the Australian summer of 2012-13. In fact it did not register as positive until January 2014. There's more to it than that, in any case.

Heat, Heat Waves and Angry Australian Summers (and Years)

I recently wrote a short article about the summer of 2012-13 in Australia. It got some reaction from one person in particular who was claiming the record heat couldn't be attributed to global warming, he postulated that it was caused by the Pacific Decadal Oscillation (eventually having some comments moved).

Rum Runner's challenge

He also posed a challenge. Rum Runner wrote: (October 9, 2014 at 2:26 AM)

@Lou "Why do you think I run this blog?"
A sense of empowerment I suppose. On other people's blogs you'd have your ass handed to you on a plate in an open debate. But here you can just *pop* delete any responses that are a bit too challenging for you.

I assume that by Lou he meant Sou. Here are the comments Rum Runner would have been talking about.

Now since Rum Runner regards the prestigious Bulletin of the American Meteorological Society as "political advocacy", and says that therefore doesn't take his information from there; and since he doesn't seem to have recognised as Australians, the scientists who wrote the papers I referred him to, I'll admit it's not much of a challenge.

Still, I thought it worthwhile doing two things. First, reporting some of the latest scientific findings about the weather Australia experienced in 2012 and 2013. And secondly, briefly touching on the Pacific Decadal Oscillation (PDO) - what it is and what is known about it and its effects on weather - in Australia and elsewhere. (I've written about the PDO a couple of times - here and here.) This article is about the former. I'll be writing a separate article on the PDO in the near future.

Australia looks forward to still hotter from the extra CO2

There are four papers in the BAMS supplement relating to the years 2012 and 2013.

The first one is: "The role of anthropogenic forcing in the record 2013 Australia-wide annual and spring temperatures" by Sophie C Lewis and David J Karoly.

What they did was investigate the roles of anthropogenic climate change and natural variability in regard to the record-breaking heat of 2013.

Robert Balic at WUWT tries to downplay Australia's Angry Summer - but who's fooling who?

I'll only comment on this protest at WUWT because it's about Australia. Anthony Watts has posted a "guest essay" by someone called Robert Balic (archived here).

Robert is writing about Australia's Angry Summer of 2012-13. I've written about that myself, for example here.

It was a doozy. Here again is the animated graphic showing twelve days of the extraordinary coverage of the heat wave that hung about. Look closely (you can click on the image to enlarge it). See what temperatures the dark red, light brown and dark brown are. Australia can get hot, but it's never been that hot everywhere before.

Source: Bureau of Meteorology

Viv Forbes, coal company director, sez it's not really hot down under (when it is!)

Viv Forbes, a coal company director from Australia, has posted another article at WUWT (archived here).  He put up a map of Australia with a whole bunch of record high temperatures in different years. I think he was trying to argue that Australia's Angry Summer wasn't "unprecedented".  He'd have been wrong.  It was unprecedented in all sorts of ways. What he wrote was:

No doubt we will hear how the current heatwaves in Australia are “unprecedented” and evidence of dangerous man-made global warming.

They are neither “global” nor “unprecedented”.

Okay, so Viv wasn't talking about last summer, he was pre-empting any discussion about this summer.  (Last summer would be hard to beat in terms of heat records.  It's already been documented that last year's summer was "unprecedented".)  As for not being global - of course not.  It's winter up north.  You can't expect heat waves in winter. But first, let's look at the big flaw in his argument.

Hot somewhere some time isn't the same as hot everywhere at the same time

Viv put up a gaily coloured chart modeled on the chart from the then Climate Commission (which re-emerged as the Climate Council after the Abbott Government shut it down).  The difference was that the Climate Commission chart was for a single summer and showed the record heat right across the continent.  Viv's chart by contrast, showed record temperatures at single locations for particular years - which varied from 1912 through to 2009.

Look at the difference in this animated comparison.  The denier chart has to span 97 years to show hot records in a lot of different single locations at different times.  Australia's Angry Summer spanned just 90 days in the summer of 2012-13:

Viv Forbes thinks WUWT readers are pretty dumb.  I don't blame him for thinking this.  They may excel intellectually in other subjects but when it comes to weather and climate they are very dumb.

HotWhopper readers by contrast know very well that you can have a record heat wave across a continent without breaking a heat record in any single locality.  That's because if it's hot everywhere the the whole continent is hot (by definition).  You don't have to break hot records anywhere to be hot everywhere all at the same time.

However even if there's a heat record broken in one place at any one time, it can be cool elsewhere.  So the continent as a whole may not be excessively hot.  (I wrote that bit for the benefit of anyone who's strayed here from WUWT.  By visiting WUWT, they could easily have lost several IQ points and I want to help recover them.  If you need it elaborated further I've explained it with charts and numbers in this article.)

Look at this map of Australia and you'll see what I mean. (As always, click to enlarge).

Source: BoM

Now compare the above with our Angry Summer of 2013 and notice just how widespread that heat wave was, plus the fact it lasted a couple of weeks:

Viv goes on to write about another heat wave.  That one was back in 1896, so it was before Australia-wide records maintained by BoM.  However look at what he wrote:

In the great heatwave of 1896, with nearly 200 deaths, the temperature at Bourke did not fall below 45.6 degC for six weeks, and the maximum was 53.3 degC. Bushfires raged throughout NSW and 66 people perished in the heat.

In 1897, Perth had an 18 day heatwave with a record of 43.3 degC. Other heatwaves were reported at Winton, 1891, Melbourne 1892, Boulia 1901, Sydney 1903, Perth 1906 and so on.

Yes, there have been heat waves in the past in Australia.  However he's lying about temperatures at Bourke - see FrankD's comment below. And do you see what else he's done?  Viv is trying to argue that Australia has been hotter in the past.  All he's actually shown was in different years, different parts of Australia had heat waves.  That's different to what we have been seeing in recent years.  The national record maintained by BoM starts after Viv's last year.  Just the same it's worth looking at the record and comparing early years of the twentieth century with recent years.

Here's an animation showing maximum and mean temperatures for all Australia.  Notice the stark difference between early last century and the last few years.

Source: BoM

For people who are not used to charts, I'll point out that to work out the difference between now and then you need to sum the minuses and pluses.  Last year had an anomaly of almost +1.5 degrees and at the turn of the century temperatures were about 0.5 below zero.  So 2013 was around two degrees Celsius hotter than it was in the early 1910s.  That's for the entire continent for an entire year.  That's a lot hotter!

I hope you now see the tricks deniers play.  Especially people like Viv Forbes who have a vested interest, such as keeping share prices of coal companies as high as possible.  The fact he's a coal company director should have no bearing on his views on climate science.  But now you know that Viv Forbes is a climate disinformer, you could be excused for pointing to his coal company directorship as a reason - but not an excuse.

Viv talked about Australia's heat waves not proving global warming.  Of course they don't.  They are consistent with global warming.  So has the world warmed since Viv's early records around a hundred years ago?  You bet it has.

 From the WUWT comments

The very first comment is a classic denier "I remember when it was hot in summer" from cnxtim, who says:

January 20, 2014 at 8:28 pm
Without doubt this AGW scaremongering is sheer poppycock.
I remember many a stinking hot summer as a child in western Sydney and around 1954 where thetemperature was over 112 degrees Fahrenheit at Penrith in NSW for many days on end over the Christmas holidays at my uncles farm.

I couldn't find any records for Penrith itself for the 1950s, but I did notice that Penrith hit 46.5 degrees last January (115.7 Fahrenheit).  It does get hot there.  Update: I found data for Richmond RAAF, which is only 18.5 km away.  It wasn't hot in 1954 - temperatures then maxed out at 37.3 Celsius in December and there was no monthly average above 30C.  It was a mild summer in Jan-Feb. It wasn't 1955, 1956, 1957, 1958 or 1959 either.  It was cooler in the 1950s than now. I went to Observatory Hill for the early 1950s. Nope - not a hot summer in sight!


craig eyles I think is talking about last week's heat wave when it stayed above 40 degrees for about a week across much of Victoria (Gippsland is in south eastern Victoria and is one of the cooler regions normally).  He says:

January 20, 2014 at 8:48 pm
This is the “anti-global warming” Govt we have in power in Australia. Yes, global warming is shite, but in my 44 years haven’t been in 4 days of 40+ degree temps & I’m in Gippsland. Friday felt like time I went to Sacramento 1999.

There are lots of people who are confusing hot weather in different places at different times with continent wide warming all at the same time.  Stephen B says:

January 20, 2014 at 10:55 pm
Last week was my birthday and I was reminded by my mother that when I was born 55 years ago I came 3 weks premature, brought on by the extreme heat wave that week in Warragul (Gippsland) Victoria – 4 days above 40 degrees. Nothing new.

Nick Stokes (who I haven't seen at WUWT for a while) says:

January 20, 2014 at 11:04 pm
This is an odd post – lots on temps in the past, but no numbers on the actual heat last week. It was very hot (here is my complaint at the time). Max temperatures in Melbourne for the first 5 days of the Australian Open were 31.1, 42.8,41.7, 43.9 and 43.9°C. Or, if you prefer, 88, 109, 107, 111, 111°F.

Now we’ve seen hotter days. And even a longer heat wave, in 1908, where maxima were close to or above 40 for six days. But they are rare. From 1855 to 2013, Melbourne averaged 1.3 days per summer in total exceeding 40°C. For the last thirty years, the average has been 1.7. So four consecutive days well over 40 is bound to attract comment.

That'll about do.  You can imagine the rest.  Mostly of the "I remember when" type or the climate conspiracy variation: "BoM is part of the worldwide climate hoax consortium and has adjusted all the old records".  If you want to suffer more they are archived here.

The Angry Year: Australia's hottest 12 months on record

Australia's had its Angry Summer made worse by humans, now it's just had its hottest 12 months from spring to winter on record.  From The Age:

Australia has just experienced its warmest 12 months since climate records began.

Data monitoring by the Bureau of Meteorology shows the average temperature throughout Australia in the year to August 31 was 1.11 degrees above the long-term average. (Note from Sou - that's the 1961-1990 average, which is warmer than preceding periods)

The nation's fourth-warmest spring on record morphed into the hottest summer on record. And now the seventh-warmest autumn has been followed by the third-warmest winter Australians have ever experienced.

In Victoria, it was the warmest winter on record, just pipping the winter of 2005.

In New South Wales, it was the second warmest, eclipsed only by the winter of 2009.

And across the nation, winter was 1.29 degrees warmer than the long-term average – defined as the years from 1961 to 1990 (which were themselves warmer than the first half of their century).

Read the rest here in The Age.

And the dreadful thing is that we could be electing a government that is pretty well intent on making the climate worse, with a potential PM who doesn't care about climate change or global warming and has even said it's "crap".  What to do?  Let's just hope the Senate doesn't cave.

The catalyst for hearing problems of an engineer

An engineer, Bob Fernley-Jones, has written an article for Anthony Watts' blog, wattsupwiththat.  You can read the archived version here (updated)  (old version here) to save going to WUWT.  It's about a recent showing of Catalyst on Australia's ABC.  The episode was climate change and extreme events.

Before I go any further let me explain the title.  There are a lot of climate hawks who are engineers.  There are a lot of intelligent educated engineers out there.  However for some reason, climate science denial attracts engineers, which is why I mention in the title that Bob is an engineer.  He said so.

You can see the show here.  It's quite good for a short segment.  It runs for about 18 minutes.  There's a transcript as well as a Q&A.

 Back to Bob.  He complains of hearing problems.  Bob shows these screen grabs from the show. Click the image to enlarge it.

This is what Bob writes (his words shriek his ideology, don't they):

The narration elucidated how these bell curves clarified why the weather had become more extreme in the past decade, and, being a tad curious I searched around for the source, but without success. My closest find is contained in a report by our Oz government funded Climate Commission entitled The Angry Summer. (2012/3 DJF) This august body is headed by Prof Tim Flannery and amongst its expert advisors is Prof David Karoly, about whom I guess many overseas readers have heard?

But, engineers like me tend to be suspicious, and one thing I puzzled on was that the change in global average T of 0.80 C took place over a period of ~160 years according to HadCRU, and that the Catalyst show implied that the alleged effects were concentrated into the last decade.

Bob bases an article about the fact that his hearing is deficient, or maybe it's a matter of confirmation bias.  I'm thinking Bob's eyesight might be affected too, because the web page he refers readers to has the complete transcript.  Bob said that the Catalyst show implied that the alleged effects were concentrated into the last decade.  Here are the relevant sections from the transcript.  These are the only statements that mention 0.8 degrees.

Anja Taylor
Global average temperatures have only increased by 0.8 of a degree Celsius. One would think that this would just lead to slightly warmer summers. But, actually, it's greatly increasing the chances of extremely hot weather....

NARRATION
Although an exceptional year, it's not outside the range of what's now considered normal. If you plot temperature records, they fall in a typical bell-curve pattern, with the majority only a small deviation from the average, and the outliers representing extreme hot or cold events. With a 0.8 degree rise in temperature, a much larger portion now sits in the warmer-than-average section, and hot to extremely hot days are far more frequent....

Dr Susan Wijffels
We're already starting to detect and see big changes in the extreme events. And we've only really warmed the Earth by 0.8 of a degree. If we were to warm the Earth by 3 or 4 degrees, the changes in the hydrological cycle could be near 30 percent. I mean, that's just a huge change, and it's very hard for us to imagine....

So nope! Not the hint of a suggestion that it warmed 0.8 degrees in only a decade.  Any normal person would probably think - ah, since industrialisation it's warmed by 0.8 degrees.  Or they might think, since global warming started earth has warmed by 0.8 degrees.  Bob's funny.

He got quite interested in the show and put a number of questions to the Catalyst team.  For example as par of one question he writes, referring to a paper  on the Russian heat wave:

 So, since that was peer reviewed it is not necessary to look any further right?
Yet, elsewhere, and whilst others also claim that it was within centennial natural variability, apparently there was conflict in other peer reviewed studies based on computer modelling that the likelihood of such events is increasing, (based on one recent event, uh?).

Bob isn't a scientist so we should cut him some slack.  If he's ever written a report he probably thinks that's all that needs to be said on the matter and no-one will ever contradict him.  That's not how science works though.  Science is full of contradictions.  That's what makes it fun. Someone will say one thing, another will disagree, more evidence is ferreted out and analysed.  People will look at it all different ways and, depending on the level of interest in the topic at hand, eventually with enough evidence and enough thinking on the matter of how to interpret the evidence, a consensus will be reached.  The more evidence supporting an explanation the stronger the consensus.  Bob seems to think every item of interest only gets picked up once by one person or a team, looked at and then put in a cupboard never to be looked at by anyone else ever again.

With the Russian heat wave there have been papers that differ in one respect or other.  In fact a lot of people have now studied the Russian heat wave of 2010.  For example:

• Trenberth and Fasullo (2012) Climate extremes and climate change: The Russian heat wave and other climate extremes of 2010, J. Geophys. Res., 117, D17103, doi:10.1029/2012JD018020
• Coumou and Rahmstorf (2012), A decade of weather extremes, Nature Climate Change doi:10.1038/nclimate1452
• Otto et al (2012) Reconciling two approaches to attribution of the 2010 Russian heat wave, GRL DOI: 10.1029/2011GL050422
• and more

Getting back to WUWT, Bob decides the bell curves for temperature as shown above are wrong and he's come up with some alternatives, which readers will enjoy.  Click for larger version.

What Bob seems to have done is mixed up global temperatures with local temperatures - or something like that.  It's really not clear what he is trying to portray.  Anyway, it's got pretty colours.  It's much prettier than Christopher Monckton's yucky pink charts.

How engineer, Bob Fernley-Jones fails arithmetic 

Bob's a bit of a funny one.  As well as having deficient hearing and eyesight when it comes to things climate, he's also not crash hot at arithmetic.  Which is strange for an engineer.  He isn't aware that you can have a summer across an entire continent in the hottest on record without having any state or territory being the hottest on record.

I've covered this before because it turns out that a lot of climate science deniers are very poor at arithmetic, especially the notion of averages.  They must have been away that day at primary school and never had to average anything since.  The following is part of what I wrote some time ago:

Here's a series of numbers to illustrate.  It is sets of numbers grouped by year.  In all but the last two years, at least one of A, B, C, D or E has the maximum for all years.  Each one has a "record" highlighted.  Yet the average for Year 5 is greater than the average in any prior year even though none of A through E has a record in Year 5.

You can read the full article here.

Perhaps Bob has children at school who can give him a remedial lesson on averages.

Bob Fernley-Jones is very organised

Bob has some strengths.  He is very organised.  He broke his article into "Parts".  Here is Part 3.

Part 3:Breaking the mood with something almost amusing:
I’ve also submitted a wider ranging formal complaint to our taxpayer funded ABC, concerning the bias and other stuff in this story, (the ABC is required by statute to serve the public, and breached its own editorial policies). I closed the complaint off with this:

Ms [Anja] Taylor was the declared presenter, producer and researcher for this show. She presented almost entirely extreme views with an apparent lack of investigative journalism. With the exception of Dr Fischer’s input about the warming effect of dry soils, (which is not controversial if we ignore Prof David Karoly), all other topics were either demonstrably false or controversial. Not content with presenting scientific material facts and balance, (the Editorial Policies require impartiality), she adds inappropriate drama and irrelevance including these images:

Bob included some screenshots from the video to show what he was referring to.  There was "inappropriate drama".  Remember, conservative science deniers don't like drama - it makes them scared. They prefer someone to tell them there is no need to be scared.

There's more and you can read the full article without having to go to WUWT by clicking here for an archived version (updated).

From the WUWT comments

Philip Bradley is a pedant.  He reckons that extreme should be relative to the present, not the past.  What would have been extreme yesterday won't be considered extreme in the future.  At least he seems to accept the world is warming, which is unusual for WUWT.  He says:

August 28, 2013 at 3:13 am
The narration elucidated how these bell curves clarified why the weather had become more extreme in the past decade

The usual statistical ignorance. If weather/temperature continues a normal distribution with the same SD, which that image shows, then by definition extreme weather stays the same, although of course the average changes.

thingadonta asks about our winters and I imagine he's saying there should be a bigger fuss made of the record warm winters, too.  They are not so angrily cold:

August 28, 2013 at 3:32 am
Why doesn’t the Climate Commission report on the lack of angry winters since Australia has gotten warmer…..also supposedly due to human activities.

This is for thingadonta from the Sydney Morning Herald:

David L. thinks nothing is extreme unless a record is broken.  (He ought to come here during one of our extreme heat waves.)  David says:

August 28, 2013 at 4:03 am
They’ve started the “extreme weather” meme. Here in Philadelphia I can’t watch a news program without being told of some extreme weather going on somewhere in the country. Just yesterday it was the “extreme, near record temperatures in the mid west”. (How can a near record be extreme?). What was the temperature? 92F. I’m sorry, but 92F is not extreme, even if it lasts 3 days and becomes the dreaded “heat wave”. Oh my! Then we ha the extreme dust cloud, the extreme rain, the extreme flooding, and the extreme forest fires all in the same day! Wow ! The end is surely near….except I remember seeing these things every summer going back to the 1960′s.. In 1973 92F was hot weather, in 2013 it’s extreme weather.

But does the average person fall for this propaganda? When you’re told that 92F is extreme, do you really believe it’s extreme? I certainly don’t and I suspect they’re trying to sell me something.

JohnC might volunteer to teach the remedial arithmetic class:

August 28, 2013 at 7:12 am
The Other Phil is (regrettably) incorrect. Of the 3 types of averages, mean is the one fairly described as dividing an area in half.
Mean – Sum of all members divided by how many members (of a set)
Median – Middle number (after sorting in numerical order)
Mode – Most Common Number
For example: of the set 1 1 1 2 2 3 11
Mean 3 [21/7 = 3]
Median 2 [(1 1 1) 2 (2 3 11)]
Mode 1 [(1 1 1) 2 2 3 11]

Leo G is, to put it politely, confused about the 0.8 degrees:

August 28, 2013 at 5:58 am
If the land surface temperature anomaly for the full set of Australian stations shows a 10-year shift of 0.8 degree C- which appears to correspond to 1SD- then there must be a significant systematic error in play (cyclical variation perhaps).

charles nelson is probably under the illusion that by getting rid of the Climate Commission all talk of climate change will stop and he'll have nothing to moan about:

August 28, 2013 at 4:49 am
There will be a new Government in Australia in a few weeks, and they will not forget the ruthless campaign the ABC ran in support of Green/Labor. The Climate Commission too is ‘toast’ as the Aussies say. This is their last squeal.

Selective memories of climate science deniers

In a guest post on WUWT, a science denier called Alan Caruba writes an article titled: "Short Meteorological Memories".  He draws together a couple of denier memes.

How can one remember something that hasn't ever happened in living memory?

Caruba writes:

What I always find interesting is the way much of the population seems to have absolutely no memory of any previous heat wave or, for that matter, a major blizzard. Either way the news media goes bananas, usually seeing it an apocalyptic scenario. No, it’s just a perfectly normal heat wave or blizzard.

That may be true or not in any one instance.  Caruba does mention the record heat Australia had last January where the average for the entire continent hit 40.3 degrees Celsius (104.6 degrees Fahrenheit).  That's not a hot temperature in one location, which, while extra hot, would no longer be unremarkable in many parts of Australia these days.  What it is is the average maximum across the entire continent of Australia.

Just think how hot it must have got over such a vast area to record a continent-wide average of 40.3 degrees Celsius.  Not only that, but there have only been 21 days in 102 years where the average maximum temperature for the whole of Australia has exceeded 39°C; eight of these days happened last summer.

I doubt there'd be anyone living today who would have a prior memory of anything like that because it hadn't happened before in the entire instrumental record.  You can see just how hot the continent was in this animated gif chart. (Click to enlarge.)

Global warming causes climate change

Caruba goes on about terminology, claiming that "climate change" has replaced "global warming".  Not so.  The terms are not identical.  Global warming signifies the earth heating up.  Climate change is what happens as a result. Here are some references to the two terms going back some time:

• The Carbon Dioxide Theory of Climatic Change by Gilbert N. Plass (1956); Tellus Vlll
• Climatic Change: Are We on the Brink of a Pronounced Global Warming? by Wallace S. Broecker, published in Science in 1975
• Arctic climate's alarming change - a newspaper article from 1947 on the possibility of global warming and climate change, warning of the possibility of catastrophic rises in sea levels.

It's happened before, but not like this

Caruba then cites two extreme events (for the time) that happened thirty years apart.  One in the UK and one in the north-east USA.  Most reasonable people would come back with ten or more events that have happened in the past ten years.  Consider just these events, listed on Jeff Master's blog on Wunderground:

Earth's Deadliest Weather-Related Disasters Since 2000

1. Cyclone Nargis, Mayanmar, 2008: 138,366
2. Heat wave, Europe, 2003: 71,310
3. Heat wave, Russia, 2010: 55,736
4. Flood, India, 2013: 5,748
5. Cyclone Sidr, Bangladesh, 2007: 4234
6. Heat wave, Europe, 2006: 3418
7. Hurricane Jeanne, Haiti: 2004, 2754
8. Flood, Haiti, May 2004: 2665
9. Flood, Pakistan, 2010: 1985
10. Typhoon Bopha, Philippines: 2012, 1901
11. Hurricane Katrina, U.S., 2005: 1833
12. Landslide, China, 2010: 1765

I reckon it's Alan Caruba who has a very selective memory, deliberately ignoring what is happening around the world weatherwise these days.  I'll amend the last sentence of Caruba's fluff denial of reality:

By the end of the week, deniers on WUWT are sure to issue another boring claim that the latest weather disaster is "nothing new to see, climate is always changing, CO2 levels were higher 3 billion years ago". Ignore them.

An uncommon misperception about Australia's Angry Summer

It is very odd how many science deniers from Australia and the USA keep trying to deny the fact that last summer was the hottest on record for Australia.  This is despite all the evidence such as the dreadful infernos across most states, but particularly in Tasmania and NSW; and the searing heatwave across the continent in the first half of January.

Here is an animated chart showing mean and maximum summer temperatures from the Bureau of Meteorology. Click to enlarge:

Data Sources: BoM Mean Summer and Maximum Summer

Here is an animation of the temperatures across Australia in early January. Notice the huge areas above 39, 42 and 45 degrees Celsius:

Source: BoM

How could it be the hottest summer for Australia when it wasn't the hottest summer for any one state?

I've come across a couple of people who are wondering how can this past summer have been a record hot summer for Australia given that it was not a record hot summer for any state or territory.

Here is why that can be. 

This first chart shows the summer maximum temperatures for states and territories going back to 1999. Click to enlarge.  

Data Source: BoM

You can see that most years when some states were hot, others were cooler, even below the mean.  In 2012-13 on the other hand, it was hot everywhere at the same time.  The columns are all clumped up together.  So even though every state and territory had at one time a hotter summer, at no time have all states and territories been this hot all in the one summer.

In this next chart I've stacked the temperature anomalies so you can see it more easily. Note that these don't translate to the Australia-wide chart because the area of each state and territory differs.  They are purely to illustrate the fact that you can have no single "highest" but still have a "highest" in the aggregate.  (Click to enlarge.)

Data Source: BoM

You may have noticed that Australia has had cooler summers, particularly in 1999, 2001 and 2010.  To get some perspective on that, go back to the top chart, which goes back to 1910.  Here is a stacked chart of the States and Territories for the same time span.  I don't think we'll see a summer as cold as 1916 again, and probably not even one as cold as 1973 or 1975.

Data Source: BoM

The same proviso applies to this stacked chart.  It doesn't translate to the Australia-wide chart because the area of each state and territory differs.  It is purely for illustrative purposes.

If after that you are still not clear on how could it be the hottest summer for Australia when it wasn't the hottest summer for any one state, try this for yourself.  It's a matter of simple arithmetic.

Here's a series of numbers to illustrate.  It is sets of numbers grouped by year.  In all but the last two years, at least one of A, B, C, D or E has the maximum for all years.  Each one has a "record" highlighted.  Yet the average for Year 5 is greater than the average in any prior year even though none of A through E has a record in Year 5.

From the comments at WUWT

Most of my readers are probably wondering why I'm stating the obvious.  You would be surprised that some people don't "get" this.  Some examples:

Paul Homewood says:
June 29, 2013 at 3:56 am  Hottest summer or not, the facts are that not a single state recorded their hottest.

In a longer comment in which he complains at length about Tamino's article on this topic, Gonzo says:

June 29, 2013 at 10:28 am  BTW how many state heat records were broken during the “angry” summer? Oh none!

Which drew this response from Anthony Watts:

REPLY: there’s no point in paying attention to Grant Foster aka “Tamino” his rants are irrelevant – Anthony

Which is funny coming from someone who doesn't know a baseline from a waist line.

Deniers are Angered by More Angry Summers to Come

There are a number of fake skeptics trying to find evidence to refute the fact that Australia had a very, very hot summer in 2012-13.  The reason they are revisiting this is because of a new paper by Lewis et al, which can be found here (subs req'd).  From the press release:

Lead author, Dr Sophie Lewis from the University of Melbourne and the ARC Centre of Excellence for Climate Systems Science said the study showed it was possible to say with more than 90 per cent confidence, that human influences on the atmosphere dramatically increased the likelihood of the extreme summer of 2013.

“Our research has shown that due to greenhouse gas emissions, these types of extreme summers will become even more frequent and more severe in the future,” she said.

I figured that with all that the fake skeptics are doing, I'd join in the fun and compare the UAH satellite data for the lower troposphere with the Australian Bureau of Meteorology land surface data (mean temperature).

I've only looked at January, which in 2013 was the month when that amazing heat wave lingered.  I've plotted the temperatures as well as the 5 year moving averages.  I don't know how UAH selects their data for Australia.  It's got a ragged coastline so I don't expect it's that easy.  Anyway, here is the result as an animated gif. Click the chart to enlarge it:

Data sources: UAH and BoM

The temperatures seem to be tracking each other more or less, with the land surface hotter than the air above it for some stretches.

Getting back to the Lewis paper that warns there are more angry summers to come, here is what the fake skeptic Anthony Watts wrote on WUWT. (In case you're wondering, Anthony recognised co-author David Karoly's name and he figured that would get the mob's blood pressure to rise):

June 28, 2013 at 4:44 am   Thanks Bob. My point in publishing the “angry” Australian claim by Karoly was that given the broad reach of WUWT, somebody would see what a load of codswallop it was and write a rebuttal, and I was right.

UPDATE: I see Nick is here working on an angle to defend the Karoly and Lewis govsci effort, so I’m even more sure it’s codswallop.

Anthony isn't up to writing a "rebuttal".  He wouldn't know where to start.  Bob doesn't mind having a shot but of course he does nothing remotely resembling the detailed analysis of the real scientists.  Thing is, Bob Tisdale started out without using Australia's land surface data.  He used reanalysis data - that dreadful modeled stuff that all the fake skeptics hate so much.

Finally he put up some charts with land surface data from BoM.  I'm not quite sure what he was trying to achieve, but I don't think he achieved it.

I may look at the paper (and what deniers say about it) over the weekend and write some more about it.

Calculating the cost of climate change

Deniers are all in a tizzy because apparently last summer wasn't the worst ever for insured losses in Australia.  (Note that some Australian deniers are so blind to reality that they think the world is about to enter an ice age, so I wouldn't take them seriously.)

Apparently the insured value of lives lost, properties flooded (many repeatedly), public roads destroyed and homes and businesses burnt to the ground across Australia this past summer was not as high (or maybe not as many were insured) as the insured losses when 24,000 properties and thousands of vehicles were damaged by the freak hail storm in Sydney in 1999.  (Click here for the government's estimated costs for flood recovery in just Queensland, not Australia as a whole.)

Sydney real estate is among the most expensive in the world.  I'm not convinced that it is very meaningful to compare insured losses for a one-off event that predominately affected Sydney with the loss of life and livestock and the widespread damage to public infrastructure, homes and businesses across the country over the whole of last summer.

As far as I know, there are some potentially big costs that are not reflected in 'insured losses' (not counting the uninsured losses).  One example is the cost of business interruption (as a result of power outages, destroyed rail, road and communications infrastructure, damaged and destroyed property of suppliers / customers, closure of ports etc).  Businesses can incur ongoing extra costs for many months when, for example, the destruction of railways, roads and bridges means that normal transport routes are not available and alternative longer routes are the only option.  'Insured losses' would not adequately account for the broader impact on regions affected, such as how it affects tourism. Nor are they an adequate measure of the social toll, on people who have lost family members or who are trying to recover from trauma as well as property loss.

This past year wasn't as disastrous as 2010-11, during which much of the continent was inundated with water as were several other places in the world.  So much so that there was a measurable drop in sea level.  But that was a La Nina year.  2012-13 was neither La Nina or El Nino.  Heaven help us when the next strong ENSO event comes.

Seems to me we need another type of socio-economic valuation if we are to properly work out the cost to Australians of all the damage from adverse weather events as the climate changes.

Australia's Angry Summer

The Climate on Steroids

From Ten News (of all places!)

The report from the Climate Commission

Here is a link to the Climate Commission report, "The Angry Summer".

Key facts: 

1. The Australian summer over 2012 and 2013 has been defined by extreme weather events across much of the continent, including record-breaking heat, severe bushfires, extreme rainfall and damaging flooding. Extreme heatwaves and catastrophic bushfire conditions during the Angry Summer were made worse by climate change. 
2. All weather, including extreme weather events is influenced by climate change. All extreme weather events are now occurring in a climate system that is warmer and moister than it was 50 years ago. This influences the nature, impact and intensity of extreme weather events. 
3. Australia’s Angry Summer shows that climate change is already adversely affecting Australians. The significant impacts of extreme weather on people, property, communities and the environment highlight the serious consequences of failing to adequately address climate change. 
4. It is highly likely that extreme hot weather will become even more frequent and severe in Australia and around the globe, over the coming decades. The decisions we make this decade will largely determine the severity of climate change and its influence on extreme events for our grandchildren. 
5. It is critical that we are aware of the influence of climate change on many types of extreme weather so that communities, emergency services and governments prepare for the risk of increasingly severe and frequent extreme weather.

Let's repeat one critical sentence:

The decisions we make this decade will largely determine the severity of climate change and its influence on extreme events for our grandchildren. 

This is The Critical Decade!

I believe it's fair to say that this decade has seen more record-breaking  and more extreme heat, fires, drought and floods than any similar length period in the past century in Australia, with accompanying loss of life, property, distress and chaos.  If we combine all this century's events, it would come close to the devastation wreaked by weather in the whole of the last century combined.  The Canberra fires; the Black Saturday fires; the Lockyer Valley floods; many places experienced two or more 100 year floods in a single year; the big drought and more.  And this is just the beginning.

The reaction by some people is dismissive.  Some will even point to a single event 70 years ago.  "What about the 1939 heatwave?", asks Ronsterm on HotCopper.  The answer is that the 39 heatwave wasn't part of the overall hotter temperatures we're seeing today.  These days we keep seeing records tumble year after year.  Look at a temperature chart for Australia over time - the answer's in the mean temperature for Australia from the Bureau (click here for other trends, such as the trend in maximums) (click image for larger version)

Here again is an animation of part of the Big Aussie Heatwave (click image for larger version):

Others like HotCopper's Watso make inane comments like: "it's colder in the northern hemisphere".  Does he think the arctic ice is melting so dramatically because it is colder? Did the USA just have its hottest year on record because it's colder?  Did upwards of 50,000 people die in the 2003 European heat wave, or 15,000 or more in the recent Russian heatwave because it was so cold?  (Watso could be simply referring to the fact that it's winter in the northern hemisphere while it's summer in Australia - now that would be inane!)

A Shift in the Climate

No - what's happening is that climates are shifting and we are experiencing the effects in day to day weather.

Deniers resort to picking random one-off weather events going back decades to match any one of the destructive weather events that have become more and more frequent in the past thirty years so and are commonplace this century.  

Disaster Fatigue

It's not just that we are experiencing heat, fires, floods and droughts it's that they are no longer one off events.  They are becoming so common that they no longer get the news coverage they used to get in times gone by eg the latest massive floods in Queensland and NSW.  The news outlets figure people down south are suffering flood fatigue.  Imagine what the poor people living in places like Gympie feel.

“I don’t think any other place in Queensland has had five floods in two years, four in 12 months, and two of those back-to-back in the last four weeks,”