A Warming Australia: Fact or Fiction?
January 16th, 2013 by Warwick HughesContributed by William Kininmonth
The media has recently been reporting apparently unprecedented heat in Central Australia in the context of human-caused climate change. But is the current heat wave, with extended periods of days above 40°C at Alice Springs really unprecedented? To answer this question it is necessary to examine the data.
There are two sites at Alice Springs for which readily accessible temperature data are available. The first is the Alice Springs Post Office commencing in 1878 and ceasing in 1953; the other is the Alice Springs airport commencing in 1941 and currently the official observing site for Alice Springs. The sites are about 10 km apart; the difference in January monthly mean maximum temperatures between the sites during the period of common observations (1943-53) was 0.2°C with the airport being the warmer of the two.
For the airport site the January monthly mean maximum temperature for all years of record (1942-2012) is 36.2°C. The monthly mean January maximum temperature for all years (1879-1953) at the Post Office is 0.3°C cooler at 35.9°C. The impression is that, when combined, we have a relatively homogeneous maximum temperature record for Alice Springs that spans 134 years.
The airport site is the basis for conclusions being drawn that warming has occurred during the second half of the 20th century. The 95th percentile for the monthly mean maximum temperature data is 39.0°C; five years exceeded this value making the hottest Januarys 1994, 1999, 2004, 2006 and 2008, all in recent decades. The warmest year (2006 with a monthly mean of 40.0°C) started with 12 consecutive days above 40°C and with a subsequent 4 days above 40°C. To date, 2013 is up with these previously hot months having experienced the first 14 days with temperatures reaching 40°C or above. On these data alone one might conclude central Australia has been getting hotter.
The Post Office data, however, show a quite different picture. The 95th percentile value is 39.3°C, or 0.3°C warmer than for the airport. The hottest years from the Post Office record were 1879, 1881, 1887 and 1881, all in the late 19th century. The hottest year in the Post Office record was 1887 and had 11 days above 40°C, a brief respite then another 10 days above 40°C. Taken in isolation the Post Office record would suggest a very warm late 19th century with a cooling trend since.
When we plot the monthly mean data for both sites an extended pattern of cooling followed by warming emerges. Temperatures are now only recovering to the values of the late 19th century.
It is unfortunate that the Australian government has not considered it sufficiently important to digitise and make publicly accessible all of the meteorological records from earlier years. The Bureau of Meteorology website has a range of important statistics about changing climate but most are generated from data subsequent to 1910 and based on a digitised selection of those recorded. As a consequence, statements based on the post-1910 data that suggest an ongoing warming trend are incomplete and likely misleading.
There is fragmentary accessible data (such as the above for Alice Springs) and much anecdotal evidence to suggest that during the late 19th century over central Australia, western New South Wales and South West Queensland the temperatures were as warm as or warmer than for recent decades. Without ready access to the existing earlier meteorological data a faulty picture of a warming Australian climate is portrayed in official statements. However, based on the Alice Springs data, a coming period of cooling cannot be discounted.
Posted in BoM Australia, Surface Record | 4 Comments »
January 17th, 2013 at 2:16 pm
Hi Bill,
Just out of curiosity, do you have information as to when the Stephenson screen was installed at the Alice Springs Post Office?
Eye-balling the time series in your figure and noting the step-change around 1892, I would not be surprised if we find the screen was installed in 1892.
January 17th, 2013 at 5:12 pm
Interesting idea John – however this chart of annual T data does not indicate anything happening at that date.
I would expect a step change closing of the T range when a Stevenson Screen replaced say an open stand. I think Todd who was in charge at Adelaide was very modern and had Stevenson Screens or an equivalent deployed as early as anybody.
January 18th, 2013 at 7:17 am
A warming Australia? Not until after 2028 when the 60 year cycle has another minimum. But 500 years of cooling will start soon after.
These are the reasons Hansen was wrong …
It should be clear from the recent comments on Roy Spencer’s latest thread that Jeff Condon (owner of “The Air Vent” website) was wrong in assuming that microbolometers (infra red thermometers) disproved what Prof Claes Johnson said about how one-way spontaneous radiation cannot transfer heat from a cooler source to a warmer target.
My March 2012 paper “Radiated Energy and the Second Law of Thermodynamics” was in large part a review of what Claes had written. He and I are in frequent communication, along with about half a dozen core members of PSI who really know their physics, and we have not been proven to be incorrect on any of this by anyone offering a valid rebuttal based on valid physics.
The significance of what Claes proved in “Computational Blackbody Radiation” is that back radiation cannot affect the rate of cooling by non-radiative processes. The latter account for at least two-thirds of all the thermal energy transferred from the surface to the atmosphere.
The rate of cooling by non-radiative processes is slowed, not by back radiation, but by the presence of all air molecules at a very close temperature at the surface/atmosphere boundary. These air molecules are at the temperature they are, because Loschmidt was right and his physics, nearly 150 years old, has stood the test of time, and now been proven correct empirically. A thermal gradient does develop autonomously in a gravitational field and is more than sufficient to explain that “33 degrees of warming” supposedly due to WV and GHG. So the greenhouse is demolished and falls to the ground, which it never was warming in the first place. QED.
Doug Cotton
climate-change-theory.com
January 18th, 2013 at 2:45 pm
Sure it’s 43 degrees outside my Sydney home. But it’s not due to carbon dioxide.
It’s not just a climate standstill as now admitted. It’s a 30 year natural slight decline from 1998 to 2028. Read what Geoff Wood (qualified in astrophysics) has explained ..
www.drroyspencer.com/2013/01/waste-heat-as-a-contributor-to-observed-warming/#comment-68988
The following are excerpts ..
“As Doug has said about a dozen times, gravity modifies the mean free path between collisions. That is ‘every’ upward, ‘every’ downward ‘every’ sideways, ‘every’, ‘every’ free molecular path between collisions is modified. Therefore it is impossible for the modified ‘collisions’ that result, not to impart the gravitational ‘information’ into the macroscopic development of the gravitational thermal profile. This is the ‘diffusion’ process.
“At this point, we have a reasonable depiction of the thermal profile of ANY atmosphere. FROM BASIC PHYSICS.
“Given a simple reason why any atmosphere tends towards this isentropic profile as depicted and described by entry level physics, why would anyone look for a more complicated reason to explain what we already know!”
The point which Geoff and I make is that the “33 degrees of warming” supposedly caused by water vapour and carbon dioxide etc was already there due to the effect of gravity on the atmosphere. This happens on all planets, and also fully explains why the poles of Venus are over 720K, even though they receive less than 1W/m^2 of direct insolation from the Sun. For more detail read my article “The 21st Century New Paradigm Shift in Climate Change Science” easily found with Google. I’ve also recorded an introductory 10 minute video here youtu.be/r8YbyfqUvfY
Doug Cotton
climate-change-theory.com