Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

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How Melbourne’s Climate Has Changed: A reply to Dr David Jones (Part 2)

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IT is generally believed that there has been a decline in rainfall across Australia and that as a consequence cities like Melbourne must suffer severe water restrictions.   Indeed if you live in Melbourne you must get prior written approval to fill a swimming pool, there are strict rules explaining how and when you can water your garden, and it is illegal to wash to your car with a garden hose.

In Melbourne reducing water demand and ensuring the efficient use of water is now government policy and the public is continually reminded of this imperative. 

Melbourne’s broadsheet, The Age, recently published an opinion piece entitled ‘Our hot, dry future’ by David Jones, head of climate analysis at the Bureau of Meteorology.  The piece reinforced the popular belief that there has been a long term decline in rainfall as a consequence of climate change.  Dr Jones wrote:

“We also know that over the past 11 years Melbourne’s rainfall has been about 20% below the long-term average, and that south-east Australia as a whole has now missed out on more than a year’s worth of its normal rainfall over the duration of the event. The run-off into Melbourne’s dams has been 40% below average over this drought period compared with the longer term, while regional areas have fared even worse. And the drought hasn’t ended.”  

Total rainfall for the major water-harvesting catchments feeding Melbourne is archived on a weekly basis at the Melbourne water website  as well as total dam storage levels back to September and August 1998, respectively.   My assistant at the Institute of Public Affairs, Nichole Hoskin, asked the Water Commission if we could have this information in an excel format for ease of manipulation, but a Mark Kartasumitra, explained we would have to make-do with what was at the website.   So Nichole extracted the individual weekly values for rainfall and water storage from their archives and entered these values into a spread sheet and then plotted a chart for rainfall, shown below, and also a chart for water storage. 

There has been a steady decline in the amount of water in Melbourne’s dams since 1998, but the chart of total catchment rainfall shows no such decline.   Indeed rainfall over the last decade appears to have been fairly steady. 

When Dr Jones writes that rainfall has been 20% below the long-term average I wonder what time frame he uses by way of comparison?   When Dr Jones writes that runoff has been 40% below average it is interesting to again ponder time frames and also what changes in land management in the catchment may have contributed to the reduction.  Indeed the available data suggests that dam levels have fallen significantly even though there has been reasonable rain.

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Part 1 of ‘How Melbourne’s Climate Has Changed: A reply to Dr David Jones’ was published on October 14th, 2008, and can be read here.

Remember Taralga, Still no Windmills

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Remember that blog post from the residents of Taralga back in June 2005 explaining they did not want any windmills?

Well today I drove through the little town which is about 45 kms north of Goulburn in New South Wales (Australia).  It is very small and very cute.  

I didn’t see any windmills.

How Melbourne’s Climate Has Changed: A reply to Dr David Jones (Part 1)

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“THESE days, it can be hard to imagine how Melbourne ever earned a reputation as the gloomy, rain-filled capital of the south. But, growing up in the 1970s, my memories are full of muddy ovals, local creeks in flood and catching tadpoles in puddles that lasted for months on end. How things have changed.”

This is how David Jones, head of climate analysis at the Bureau of Meteorology, began an opinion piece entitled ‘Our hot, dry future’ published by Melbourne’s The Age newspaper on October 6, 2008.

The piece continued,

“Since 1996, each successive calendar year has brought the city below-average rainfall. With 299 millimetres recorded so far this year, and with just three months to go, it seems virtually certain that this year will become the 12th in a row that has failed to get to the average of 650 millimetres. September 2008 was the driest on record in Melbourne, and the outlook for the remainder of the year suggests that below-average rainfall will continue…

“We also know that over the past 11 years Melbourne’s rainfall has been about 20% below the long-term average, and that south-east Australia as a whole has now missed out on more than a year’s worth of its normal rainfall over the duration of the event. The run-off into Melbourne’s dams has been 40% below average over this drought period compared with the longer term, while regional areas have fared even worse. And the drought hasn’t ended.”

Dr Jones goes on to blame climate change for the drought and warns there is worse to come.

I recognise that Dr Jones is an expert on predicting future climates, but I am not sure he has adequately explained the recent past climate of Melbourne.

Climate always changes and in a country like Australia climate tends to naturally cycle between periods where there is a dominance of wet La Nina conditions and then dry El Nino. The 1950s and 1960s were very wet along the entire east coast of Australia, but since 1976 the median state of the Pacific Ocean has been towards El Nino that is dry conditions. Indeed Dr Jones was a young boy when it was relatively wet while his adult life has been dominated by El Nino conditions. Of course the built environment has also changed. Melbourne is a much more affluent city now than it was 30 years ago and along with affluence comes laser levelling of sporting venues and much improved drainage and flood mitigation so ovals dry out relatively quickly, creeks are slowed and puddles in public places now a thing of the past.

But there is more to this story.

Bill Kininmonth, a meteorologist formerly with the Bureau, has made the following comment about how the recording of Melbourne’s weather has changed over the years and how the rain gauge in Melbourne’s central business district is now sheltered from the rain bearing winds of the southwest:

“Although Melbourne’s observations commenced in 1851 the location and environment have changed over that time. The earliest observations commenced at Flagstaff Hill and then they changed to the Observatory site south of the Yarra. For more than 100 years the observations have been taken from the present site on the corner of Victoria Parade and Latrobe Street. However there has been urbanisation. The site has clearly lost exposure to the cooling southerly winds and the rain gauge is sheltered from the rain bearing winds of the southwest.

“Clearly it is difficult to draw a conclusion about Melbourne’s climate and the possibility that it might be changing. The urbanisation of the site should make the record indicate a hotter and dryer climate, whether or not that has occurred. Essendon airport was a previous non-urban locality in the vicinity but that closed in the early 1970s. Tullamarine is the current site but was not open during the dry periods of the first half of the 20th century. Laverton, likewise an early site with long data has also been closed.”

I shall post more tomorrow on Melbourne’s total catchment rainfall and water storage levels in Part 2 of ‘How Melbourne’s Climate Has Changed: A reply to Dr David Jones’

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Our hot, dry future, by David Jones, October 6, 200, The Age
http://www.theage.com.au/opinion/our-hot-dry-future-20081005-4udg.html

WWF and Greenpeace as Well-Funded Successful Modern Political Organisations

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I spent last weekend at The Annual Australian Environment Foundation (AEF) Conference at Rydges Hotel Lakeside in Canberra.  The conference theme was a ‘climate for change’.

But it wasn’t only about ‘climate change’, political analysis Graham Young spoke at the conference about the power of the internet, politics and lobbying and even mentioning this blog.  He suggested we were about “community”, “sharing information”, “understanding objections” and also “rehearsing arguments”. 

In the context of lobbying Mr Young made reference to the large environment groups’ Greenpeace and the World Wildlife Fund suggesting they are “successful modern political organisations”.  

Outspoken geologist and climate change sceptic, Bob Carter, also made mention of the same two organisations, explaining that Greenpeace with an annual budget of US$272 million  and WWF with a budget of US$487 million have more money to spend on lobbying than Australia’s major political parties during a federal election.

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There are photographs of some of the delegates and speakers at the AEF conference at the Community Web pages of this blog.
https://jennifermarohasy.com.dev.internet-thinking.com.au/blog/2008/10/aef-annual-conference/

AEF Annual Conference: Photographs from The First Day

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The Australian Environment Foundation (AEF) held its Annual Conference and AGM this last weekend in Canberra.   We heard some great speakers and also had a good time.  Photographs about to be uploaded here

After I welcomed delegates to the conference as Chair of the Australian Environment Foundation, Professor Bob Carter spoke about climate change – both warming and cooling – as a natural hazard.

  

 

 

 

 

 

 

 

Bill Kininmonth, a meteorologist formerly at the Australian Bureau of Meteorology, and Professor Don Aikin, a former Vice Chancellor of the University of Canberra, also spoke on climate change and emphasised like Professor Carter, that it is something that always changes.  

 

Gillian Hogendyk, AEF Secretary, is pictured in the front row at Rydges Lakeside.  Gillian is a Vet who lives in Warren (near Dubbo) and has spent some years studying the natural history of the Macquarie Marshes in central western New South Wales.  Gillian spoke to conference delegates about the need for controls on grazing within the marshes. 

       

Forester, Mark Poynter, is pictured here making some last minute changes to his speech notes before telling us about the River Red Gum forests of western Victoria including how controlled grazing can be a useful weed control. 

 

 

 

Well known climate change sceptic and sometimes commentator at this blog, John McLean was also at the conference.

 

 

 

Leon Ashby recorded the entire first day’s proceedings and I hope will have DVDs for sale soon.  I shall ask him to post details as a comment.

 

 

I will post more on the conference over the next week, including photographs from the dinner where comedian Dr Barry York spoke about “that movie”.   

Next year’s AEF conference and AGM will be in Perth.

Aynsley Kellow on Popular Nonsense in Perth

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A couple of weeks ago Aynsley Kellow, Professor and Head of the Department of Government at the University of Tasmania, gave a lecture in Perth. He said: 

“I am pleased to present this lecture today in Perth.I am particularly pleased to find that Perth is still here. I last visited here in 2005 – the year that Professor Tim Flannery suggested that Perth could become the first ‘ghost metropolis’ due to reductions in rainfall because of climate change.  I must confess that I was somewhat bemused by this statement, because my visit to Perth was to present a paper on water policy under climate uncertainty. I knew from my research for that paper that Perth was in fact better adapted to uncertainty in its water supply than any other capital city. 

Perth and the south-west of the state have suffered a decline in rainfall, which appears to have shifted to the north-east. The cause appears to be not the gradual accumulation of greenhouse gases, but a sudden shift in ocean currents. This decline in rainfall has translated into a marked decline in catchment yields thanks to changed catchment management, and an increased yield can be obtained by thinning catchments. 

Regardless, Perth has adapted to its natural environment with a number of responses: demand management; use of aquifers; the construction of the Kwinana industrial recycling plant; and now a desalination plant.  Professor Flannery was, of course, talking nonsense – but, as sales of his book The Weathermakers and his subsequent selection as ‘Australian of the Year’ showed, this is popular nonsense.”   

Read more here: The 2008 Harold Clough Lecture: ‘The Politics and Science of Climate Change: The Wrong Stuff’