Climate & Climate Change

Has the drought across southern Australia finally broken?

According to ABC Rural Weather: “cloud is crossing western Queensland, New South Wales, Victoria and Tasmania with a trough, generating widespread rain. Low cloud is driven across southern South Australia by cool southwesterly winds, bringing showers. Thick cloud is forming over the north near a monsoon trough, triggering heavy showers and storms.”

News Limited is reporting: “A one in 50 year monsoonal downpour dumping record rain across much of South Australia has cut off towns, stranded motorists, flooded businesses and brought smiles of joy to drought-stricken pastoralists.”

ABC Online is also reporting flooding in South Australia and heavy rain in western Victoria.

While last week national parks across central Australia received flooding rains with even the normally dry Trephina Creek to the east of Alice Springs running.

Western New South Wales may even get some good rain?

So has the drought finally broken?

“Almost every summer, there is a heat wave somewhere in the US that garners popular media attention.

During such hot spells, daily record high temperatures for various cities are routinely reported in local news reports.

A natural question arises: is global warming the cause of such heat waves or are they merely statistical fluctuations?

Intuitively, record-breaking temperature events should become less frequent with time if the average tem-
perature is stationary.

Thus it is natural to be concerned that global warming is playing a role when there is a proliferation of record-breaking temperature events. In this work, we investigate how systematic climatic changes, such as global warming, affect the magnitude and frequency of record-breaking temperatures.

We then assess the potential role of global warming by comparing our predictions both to record temperature data and to Monte Carlo simulation results…

Read the full article at Cornell University Library here: http://arxiv.org/PS_cache/physics/pdf/0509/0509088.pdf

Some months ago I suggested that media coverage of The Stern Report — an assessment of the economics of climate change by a British economist for the British government — was completely over the top. I also commented that from a quick scan there were some obvious errors of fact.

Now the journal World Economic has published a lengthy critique of The Stern Report. Part 1 of the critique deals with ‘The Science’. Written by Robert M. Carter, C. R. de Freitas, Indur M. Goklany, David Holland and Richard S. Lindzen it concludes:

“The Stern Review is biased and alarmist in its reading of the science. In particular, it displays:

• a failure to acknowledge the scope and scale of the knowledge gaps and uncertainties in climate science

• credulous acceptance of hypothetical, model-based explanations of the causality of climate phenomena

• massive overestimation of climate impacts through an implausible population scenario and one-sided treatment of the impacts literature, including reliance on agenda-driven advocacy documents

• lack of due diligence in evaluating many pivotal research studies despite the scandalous lack of disclosure of data and methods in these studies

• lack of concern for the defects and inadequacies of the peer review process as a guarantor of quality or truth.

These and other related problems arise because the Review has relied for advice almost exclusively on a small number of people and organizations that have a long history of unbalanced alarmism on the global warming
issue. Most of the research cited by the Review does not, on inspection, make a convincing case that greenhouse warming constitutes a major threat that justifies an immediate and radical policy response. Contrary research is consistently ignored, as are basic observational facts showing that alarm is unwarranted. The Review fails to present an accurate picture of scientific understanding of climate change issues, and will reinforce ill-informed alarm about climate change among the general public, the bureaucracy and the body politic. HM Government will need to look elsewhere for a balanced, impartial and authoritative review of the current climate change debate. “

The complete document from World Economics, Volume 7, Number 4, October-December 2006, can be downloaded here:

http://www.staff.livjm.ac.uk/spsbpeis/WE-STERN.pdf

Sydney will turn off its lights for one hour at 7.30pm on Saturday March 31, 2007. According to the World Wildlife Fund (WWF) this will be: “a major step towards reducing the city’s greenhouse gas pollution”.

The WWF, with the support of The City of Sydney and the NSW Government, have nick-named the event “Earth Hour” and determined that it “will be the highlight of a major campaign to encourage businesses, communities and individuals to take the simple steps needed to cut their emissions by 5 percent in 2007”.

I wonder what is special about 5 percent. Furthermore, one hour in one day of one year is not going to provide a saving of 5 percent.

If WWF was serious about a 5 percent saving then they might propose Sydney turn off all its lights for 18 days this year?

And this word “major” keeps being repeated. But it hasn’t even been suggested that football games be cancelled.

In yesterday’s The Australian it was just suggested they be rescheduled.

Now how is that going to save electricity?

It would be just like me taking a nap from 7.30pm to 8.30pm on March 31st and then stay up until say 11.30pm instead of going to bed at say 10.30pm?

Not that the sporting clubs are prepared to even go along with the idea of rescheduling with an NRL spokesman claiming: “It would be impossible for us to reschedule or fit our fixtures into this scheme”.

On March 31, at least 60,000 fans are expected to watch a rematch of last year’s Sydney Swans-West Coast Eagles AFL grand final at Telstra Stadium under big lights. While at the Aussie Stadium the NSW Waratahs and New Zealand’s Canterbury Crusaders will compete as part of rugby’s Super 14 series and at Parramatta Stadium rugby league fans will be watching the Eels take on the Wests Tigers also under full illumination.

“We are always happy to talk about ways of being more environmentally efficient but the matches must go ahead,” said the NRL spokesman.

So how could our sporting heroes be more “environmentally efficient”?

Perhaps more home games and a ban on interstate and particularly international competitions given travel is considered to be so energy inefficient?

In the media release announcing the Earth Hour, Greg Bourne, CEO of WWF-Australia, was upbeat about the importance of Sydney. He claimed that Sydney is renowned across the globe for its ability to make things happen citing the 2000 Olympic Games.

It got me thinking wouldn’t an Olympic Games be a huge source of greenhouse gases? There is all the air travel to the event from every corner of the globe by officials, athletes and all the spectators. Then there is all the lighting of many venues, heating of swimming pools, air conditioning, fast food, advertising, plastic mascots and the list goes on.

But of course we are not going to cancel the Beijing Olympics because like so much that uses energy the Olympic Games is about community, it’s about culture and its about excellence.

So why is Sydney going to turn off its lights for an hour on 31st March?

Is it also about community, a new culture of austerity and perhaps being better than everyone else?

It is certainly not about making any significant difference to the city’s greenhouse gas emissions this year or into the future.

Hi Jennifer,

There has been substantial discussion on the blog over the last few months as to the severity of the current drought afflicting much of Australia and its cause. A fair emphasis has been as to whether the current drought is the “absolute worst” on record or whether they have been “historical anecdotes and personal rainfall data sets before sufficient formal Bureau records, or paleological droughts recorded in coral cores” that were worse. Via the Australian newspaper, Barrie Hunt has contributed the results of a 10,000 year Global Climate Model run to further complicate this argument suggesting we only have a narrow view of what our real climate variability involves.

To some extent does it really matter? Is it just a public bar sports debating point. We know that the drought is widespread, severe, entrenched and multi-year in nature. It’s not much fun if you’re in the middle of it. Surely it is “among” the worst droughts on record in many important areas. All droughts have their own unique signatures and different areas show different impacts. It is simply not possible to say whether this drought is other than natural variability – although one can argue there may be climate change aspects or influences exacerbating the situation. We’ll know for sure in 30-40 years time.

What does matter is to whether we are adapting and responding to drought risk, water security, land use and population changes in a more mature manner. This involves seeing drought as part of normal and planning for it appropriately at farm, regional, industry, state and national levels.

Nevertheless I believe we do need a better spatial understanding of this multi-year drought which some have said has been building for 5, 6 or 7 years. A reasonable way to do this is to undertake a decile analysis of rainfall for the Australian rainfall network. We need to examine how bad the sequence of years are for rainfall deficit. The Bureau of Meteorology has come under quite a bit of criticism by blog commentators, but notwithstanding, I asked Dr David Jones, Head of Climate Analysis, from the National Climate Centre to supply a 5 year and a 7 year decile sequence analysis for their reference network which he has kindly provided. Why debate the issue in a data free vacuum when we can make a phone call or email !

The analyses are included as maps below.

The maps represent a 5 and 7 year decile analyses based on the sequence of 1900 till now. For example – where does the recent 5 or 7 annual rainfall sequences fit into any of the sequences since 1900.

Anyone can easily do these analyses for a single station or stations – you just need to do the mathematics of adding up the year-totals in a running mean fashion and grouping your data into decile bins. So for the five year decile – arrange your data from earliest to latest records, add up the first 5 years in the record and record the total, move the band along one on the rainfall record sequence and do it again, and so on and so on. When all done, rank the new totals highest to lowest in decile bins (0-10%, 20-30%, 30-40% and so on). You can then see where any individual sequence, or the last 5 years in this case, fits in the distribution of all 5 year sequences. Or in fine detail the lowest and highest on record.

Similar logic for the 7 year analysis.

But as you may appreciate a lot of work to do spatially and interpolate the results.

And it is important that it is done as a sequence of years – one cannot add the individual year deciles/percentiles together.

The maps unlike the time series show we live in two Australias – one wetter and one drier. In the majority of areas where we have major agriculture or urban populations we have drought issues – some moderate – some severe in parts. Meanwhile life in the Gibson desert is pretty good (relatively speaking). This why the times series data are not helpful – the addition of real good and real bad = average which doesn’t represent reality

Of course this is only rainfall – there are obvious issues of pattern and intensity of rainfall, how plants and soil respond, and antecedent conditions (i.e catchments currently dry as a chip) – if we’re debating streams and rivers I really think one needs the same analysis but on streamflow.

Similarly one can use a pasture or crop model to get decile crop yields or pasture biomass (decile of wheat and grass!) However experience suggests that often these further analyses amplify effects and it will look worse for drought. Usually same with streamflow.

I understand the Bureau will be undertaking some more work on this issue in coming months.

I encourage any readers to do their own numbers with their own data – but please explain what you have done so we’re all clear.

Cheers,
Luke.

PS obviously where station density is low – i.e. central Australia and central WA the spatial interpolation is only as good as the data point grid. But I believe we have a sufficient grid for some intelligent analysis in areas that people live or major agriculture occurs. One could obviously argue the spatial interpolation mathematics and accuracy in fine small areas (i.e. SE Qld). The data do not start in the 1890s and the Bureau do have issues with station quality before 1900. The data are of mixed quality.

During 2006 much was said and written about the “extraordinary drought” conditions here in Australia being a consequence of climate change.

I wrote various pieces suggesting that when all the data was in, rainfall for this last year, even for the Murray Darling Basin, would be within the realms of natural variability.

Well the data is now all in and here’s the rainfall graph for the Murray Darling Basin:

.

The Bureau of Meterology has also just published a summary for last year for rainfall with comment that:

“Preliminary data indicate that the average total rainfall throughout Australia for 2006 was about 490 mm, slightly more than the long-term average of 472 mm. However, it is unlikely that many Australians will remember 2006 as a wet year.

The near-normal all-Australian total was made up of well above average totals across the north and inland Western Australia cancelling out the well below average totals recorded in the southeast and far southwest.

Parts of southeast Australia experienced their driest year on record, including key catchment areas which feed the Murray and Snowy Rivers, as did parts of the Western Australian coast, including Perth. In contrast, record high falls were observed in parts of the tropics and inland Western Australia. It was the third-driest year on record for both Victoria and Tasmania, while for the broader southeast Australian region, which also takes in southeast South Australia and southern New South Wales, it was the second-driest.”

Here’s the graph from the Bureau’s report: