Interestingly, the shift circa 1972 is close to a shift that occurred about 1968 in thunderstorm days in SE Australia:

Davis, S and K.J.E. Walsh. 2008. Southeast Australian thunderstorms: Are they increasing in frequency? Australian Meteorological Magazine, 57, 1-11.

Yes Nick, CSIRO does say:”While total rainfall on the Australian continent has been relatively stable, the geographic distribution of rainfall has changed significantly over the past 50 years”And even this is a disgraceful cherry-picking misrepresentation;http://www.bom.gov.au/climate/change/rerain.shtml

Nick, you offer two possible interpretations: “While total rainfall on the Australian continent has been relatively stable [over the past 50 years], the geographic distribution of rainfall has changed significantly over the past 50 years.”"The total rainfall over Australian continent has been stable relative to the geographic distribution of rainfall that has changed significantly over the past 50 years.”The first is incorrect as shown above, the second is meaningless as total rainfall is not directly comparable with the distribution.

Nick, all I want is for changes to be put in the fullest possible context. There is no justification for talking about the last fifty years when you have a hundred or so worth of data. Unless you want to give a misleading impression in the report about the nature of long term changes. In the US, our CCSP reports tried this same BS of focusing on recent decades. They showed trends since the 1970's. Surprise, surprise! We can “hide the decline” in temperatures in the Southeast. We can show precipitation decreases in places-but if we use the full dataset, precip is going up almost everywhere.You can get certain impressions about the changes that have been going on. But the global warming that this might get blamed on happened over a full century-and using all the data can completely change the conclusion you reach. the conclusion that parts of Australia are getting wetter and parts drier is largely wrong over the long term. But this report evades telling the whole truth in favor of half truths.

Regarding eccentric break point theories:Trends in warm season thunderday incidence are examinedover southeastern Australia. There has been a significantincrease in the number of thunderdays from 1941-2004, but much of this increase may have been a result of changes in observing practices in the mid 1950s. When data earlier than this are removed, some significant trends remain. There have also been smaller increases since 1970, mostly in the early part of the warm season (October-December). These increases mayhave been caused by changes in the atmospheric processes that affect this region. Examination of temporal trends in surface and 500 hPa temperatures and several instability indices since 1970 showed an increase in temperature and an increase in the number of days that instability is present in the atmosphere, asmeasured by the Total Totals index. It is unclear whether these increases are caused by localised phenomena or changes in some larger scale meteorological processes caused by climate change or other large-scale processes. Significant issues remain regarding the homogeneity of the thunderday record.Davis, S and K.J.E. Walsh. 2008. Southeast Australian thunderstorms: Are they increasing in frequency? Australian Meteorological Magazine, 57, 1-11.http://www.bom.gov.au/amm/papers.php?year=2008http://reg.bom.gov.au/announcements/media_relea…

“Eccentric breakpoint theories”?

http://www.arl.noaa.gov/documents/JournalPDFs/Seidel&Lanzante.JGR2004.pdf

http://www-eaps.mit.edu/faculty/lindzen/203_2001GL014074.pdf

https://pantherfile.uwm.edu/kswanson/www/publications/2008GL037022_all.pdf

And so on and so forth.

A picture is worth a thousand words
http://i260.photobucket.com/albums/ii14/sherro_2008/Rainfallto2010.jpg?t=1269760940

The decade ending 2009 was the second wettest on record for the whole of Australia, with the decade ending 1979 the wettest, unless the official figures are revised.

“2. In six of the ten cases examined the best fitting models were not a simple linear fit but involved break- points. Two of the four cases in which linear models were chosen were for the troposphere during 1979 – 2001, a period in which we identified no potential breakpoints. [34] 3. The frequent choice of the sloped steps and flat steps models highlights the importance of abrupt changes. The choice of the sloped steps model for the tropospheric data suggests it is reasonable to consider most of the warming during 1958 – 2001 to have occurred at the time of the climate ‘‘regime shift,’’ modeled here at the start of 1977.”Nick must be using a definition of eccentric that means selected by objective statistical criteria. The opposite of eccentric being vested interest in green energy and carbon trading.

Steve, I want to put rainfall on the table. From my biodiversity background its just as important as temperature, economically the extremes are more costly than temperature, but its ignored or exploited. But the story is actually full of conundrums and illustrates how little is understood by the 'experts'.

David, I'd like to put rainfall into more prominence too, but there were significuant problems with evaporimeters (birds splashed in them) and there is a lack of data about water table depths IIRC. So the balance is hard to reconstruct.In an early way, I wonder if there is also value in global atmospheric pressure distribution with time. The total weight of air should stay quite constant in 100 years, with changes due mainly to the water content carried and turbulence. Re the 10 year drought in SE Australia, maybe there has been a 10 year reduction in atmospheric pressure because the air has become less moist. If not, why not? Then it feeds back into Dick Lindzen's global work. I am unsure if this is treading on old ground, so please tell me so.

Lindzen eccentric and subjective assumptions! I forgot Douglass and Knox;

http://www.pas.rochester.edu/~douglass/papers/Douglass_Knox_pla373aug31.pdf

And of course Tom Quirk, who is a nice guy, has done his paper;

http://www.lavoisier.com.au/articles/greenhouse-science/temperature-data/Quirkaustemp.pdf

Are you really saying there was not a climate shift in 1976 with temperature ramifications?

I'm sure the 'consensus' will remain that my friend Jeff Glassman is eccentric too! Check out his new article 'Solar Global Warming':http://www.rocketscientistsjournal.com/2010/03/…

Of course, rainfall has the advantage over temperature that if you lose a few days of observations the rain remains in the gauge and can be reconstructed a lower resolution, while for Hg temperatures the thermometer would stay set at extrememe max/min over those days, so more data would be lost.

Glassman is good value.

Nick; the 1976 date tallies with PDO phase shift and a host of oceanographic factors; temperature rose rapidly over the transition period; how is it not reasonable to show that the temperature history is stepped rather than incremental per linear regression when the incremental depiction falsely supports a gradualist AGW effect; or are you saying that AGW can have a step effect on temperature. If not the step or break approach to temperature is a valid rebuttal of AGW; if temperature trend is not consistent with AGW then AGW is moot.

Nick”You can apply Chow tests to all sorts of data, and find many breakpoints. DS likes doing that, but how does it help?”That is a good question but the fact remains that there certainly appears to have been (some sort of) marked climate shift evident in the Northern Territory in the 1970s as evidenced by:Annual Rainfall AnomalyAnnual Percentage Area in Decile 10 RainfallAnnual Sea Surface Temperature Anomaly(all BOM data).The fact that this shift seems to bear little relationship to the intensity of EITHER the East Asian Monsoon or of the El Nino/La Nina cycles (although the latter is clearly imposed on the shift) of the last 30-odd years has always struck me a rather curious.The facts that this did coincide with the explosive growth in the Indonesian 'Transmigrasi' program of the 1970s – 1990s (with its consequences for primary productivity of coastal waters) AND the onset (from ~1970) of frequent, major, persistent forest and peat fires in East Kalimantan and (later) West Papua (with its consequences for aerosol effects) have also always struck me as rather curious.The orthodoxy generally seems overly keen to ascribe anthropogenic climate effects to CO2 but reluctant to ascribe them to any other significant anthropogenic phenomena (temporary or long lived) – other than black carbon aerosols of course.