Climate change has been introduced by the then new Chairman of
SEQWater in her 2006 annual report. The Queensland Government has formed the "Queensland
Climate
Change Centre Of Excellence". Our Political Leaders of all persuasions
have embraced Climate Change in varying degrees. It is therefore appropriate to examine the
rainfall in the catchments in relation to this subject.
Rainfall
You are aware from other sections of this site that I have all
the rainfall data in the catchments that has ever been produced. It predates
1893 in some cases. I am therefore in a strong position to examine the rainfall
over any periods to detect Climate Change.
Thirty year periods are selected as the Bureau of Meteorology
compares all rainfall with the 30 year period 1961 to 1990. I agree that
it is a sufficient period to detect trends.
These two graphs of the Wivenhoe
and Somerset Dams do not
show any effects of Climate Change on Rainfall in the last 30 year
period 1977 to 2006.
The Wivenhoe shows a variation in the 1947 to 1976 period
which included the 1974 flood. It is a period when it was reported by that respected
United States Journal "Newsweek" that
the Scientists of this world were predicting devastation of the Planet by Global
Cooling in 50 years.
The Somerset Dam, our main provider of water, shows no
variation in absolute terms in the last 60 years.
Summer versus non-summer
There is one aspect of this area for which I am unable to
provide an explanation.
While reviewing the percentage of rainfall received by the 
four months December to March, as compared to the eight months April to November,
I noticed that there was a 4 per cent variation between the years prior to 1961
and the years 1961 to 2006. The chart used is reproduced for convenience.
While this aberration is significant to warrant attention in
this section, it has no effect on the conclusion that the Summer months receive
50 percent, or more, of the annual Rainfall.
You will see that the individual Rainfall stations in both
Dams record a similar result to the total for each Dam. Whatever happened, it is
consistent. There is sufficient rainfall in each total to make the comparison
with comfort.
Federation drought
This matter has been raised by the Qld Govt, Climate Change
Centre of Excellence. Because it was raised, I have discussed it in full under the "Federation"
button.
It is referred to in this section for the reason of its
complete departure from normal rainfall patterns.
You will read in the "Summer V Non-Summer"
above that the items of interest are the stable relationship of the Summer months 1893 to
1960. The Summer months were around 53% of the annual totals and this was
consistent with all rainfall stations in both the Wivenhoe and Somerset Dams.
The
Federation years 1898 to 1903 show a complete reversal of this position. It
was accompanied by low readings of high impact rainfall throughout the period.
The Summer months in the dams were : 35 percent in the Wivenhoe and 34 percent
in the Somerset. The balance, of course is in the non-summer months.
The Climate Change Centre of Excellence has compared the
Federation drought with the last 6 years. One finds in this web-site that the
Summer months have been perfectly normal and that the balance of rain not
received was in the low rainfall non-summer months that do not normally create
inflow. Reference " Rainfall deficiency" button.
Drought applicable to Australia
This map provided by our Leaders shows the sections of 
Australia
that were in drought in February of 2007. They have been largely affected by
recent rains. Bear
in mind that while the catchments are shown as the lowest on record, the
percentage map showed 80 percent
The position of our catchments has been generally overshadowed
by this drought and the accurate position clouded.
This article "The big dry natural and not due to 
Climate Change" was provided by the CSIRO and published in the
Australian Newspaper on the 28th December 2006.
Brisbane city flood heights 1840 to 2006
This graph of Brisbane City flood heights covers the span of
seven generations. They do not fully represent the 
rainfall
in the catchments and vice versa. However there is much similarity. Obviously
the flood activity in the eighteen hundreds was much more intense than the
twentieth century and beyond. To the casual observer this would indicate that
climate change as we know it existed at the start of the twentieth
century and continued for seventy years. It
is more likely to be a natural occurrence of Climate change somewhat similar to
the last ice age of less than 400 generations ago. It covered Alaska, Canada,
the Great Lakes and half way down the United States. The evidence is presented
in a museum in the Ohio Valley which I once visited.
Support of the Brisbane City Flood heights with the
Computer Hydrology model supplied by the Qld Government.
This aspect is fully discussed in Qld
Gov Reports and reads as follows:-
Natural climate change observed in the
computer model
The HYNF graph is useful in observing the
natural climate change over the period 1880 to 2006. When considered with the
Bureau of Meteorology flood graph for the period 1840 to 1890, a clearer
perspective of natural climate change emerges.
The period from 1840 to 1900 would have seen
the dams full for almost, if not all, of the time. It was a "Wet"
period. The period 1900 to 1950 showed major gaps and was a "Dry"
period. 1950 to date shows a "medium" period.
Climate change created by an exploding World population
and its need for energy as its circumstances improve.
This aspect is emerging from theory into hard observable
statistics. The near future will be the conclusive proof of the degree of recognition
required.
Attached is a recent article (23/04/08) in the Australian
Newspaper by Mr Phil Chapman, a Geophysicist and Astronautical Engineer. He is
Australia's only astronaut.
He points out that the World temperatures in the last decade
have held or declined. This seems to be confirmed by the proponents of global
warming.
Further, the four recognized global agencies in his attached article,
including NASA, record an alarming drop of 0.7C in 2007. He proceeds to
speculate on the consequences of a global cooling of that magnitude with no apparent
intervention.
We now have one firm part of the two part equation, a reliable
fix on global temperatures. I am not aware of the carbon dioxide global
measurement at this
point.
Conclusion
We have seen from the above that the Rainfall itself has not
altered. That the Summer months receive 50 per cent or more of the annual
rainfall still holds. That the CSIRO states that there is no influence by
Climate Change. There does appear to be a permanent shift in the pattern
of Summer months versus non-summer months to the extent of 4 per cent of total
rainfall over the last 46 years.
In the realms of conjecture, the people who insist that land
clearing affects the rainfall may well be right with the high volume summer
months being reduced marginally since 1960. This follows a documented theory of
Mr. Tim Smith of the Gold Coast and is the only suggestion on which I can draw at
this stage.
The Federation drought, on closer examination by the Climate
Change Centre of Excellence, may reveal more about changing weather patterns
than will the last 6 years of rainfall.
From the foregoing, we see that there are two types of
climate change.
(1) Natural climate change and
(2) Climate change created by an exploding World population
and its need for energy as its circumstances improve.
Climate Change created by the latter is emerging from its ephemeral nature
and into the realm of hard statistics. The foregoing are hard statistics and
provide little relief for those who may claim Climate change of this nature is the cause of
our depleted dams.
The fact remains that we must provide for both. You will
see that that the creation of an expanded Borumba Dam to 2 million ML provides
for both whereas the Traveston, with minimal storage capacity, provides for
neither.
