Climate & Climate Change

Jen,

I’ve noticed your recent thread on the long-term hydrological drought affecting eastern Australia. I’ve whipped off a few charts for you which put this into an historical context based on rainfall data going back to 1900 (some limited earlier data is available).

In terms of eastern Australia, the current meteorological drought started in early 2002 with the emergence of an El Nino event and continues to the present. The first figure below shows essentially drought “deciles” for this period.

As you can see a significant part of SE Queensland has experience its driest 55 month period on record. The data are not spatially dense enough to resolve structures at the catchments scales (though Warwick’s graphs suggest ~5 yearly rainfalls which are lowest on record).

Note that the analysis only shows those areas which are experiencing severe or serious meteorological drought (almost all of eastern Australia has experienced below average rainfall through this period).

Rainfall is only part of the drought story (drought is a function of both water supply and water demand), but it does support the general conclusion that it has been abnormally dry and probably the driest period in “of order” 100 years.

This is just one of three protracted drought periods which Australia is experiencing. Probably the most important from a water management perspective is that which started in early 1997/late 1996 in southern Australia. This is shown in the second figure.

This has seen the Perth, Canberra and Melbourne catchments all experience their lowest (or nearly so) rainfall on record. The third protracted drought event is that which commenced in SW Western Australia in the 1970s and which has been linked to a combination of greenhouse gas increases, ozone depletion and natural variability by the Indian Ocean Climate Initiative (see http://www.ioci.org.au/).

An aspect which is not covered in these analyses is the high temperatures. The third figures shows the mean temperature deciles for the period starting in 2002.

This analysis is based on the post 1950 period only (though temperatures before this time were generally considerably cooler) and uses only the high quality national temperature network discussed at http://www.bom.gov.au/climate/change/reference.shtml .

These stations have minimal or no urban heat island effects. There are a number of papers published on the increasingly warm temperatures which we now experience with droughts (as a result of global warming interacting with climate variability). As you can see almost everywhere has been warmer than average and most of Queensland has experienced its warmest 55 month period on record.

Regards,

David

We are in the middle of an election in Queensland, Australia.

My local member has just sent me a glossy brochure stating that:

“Queensland is experiencing the worst drought in 100 years …no other government in our history has faced a challenge of this enormity.”

The Premier Peter Beattie has being repeating the same message for some time.

So how bad is it – really?

The catchment with Brisbane’s dams is reportly the most severely affected.
Warwick Hughes has constructed the following graph from the rainfall record for the Wivenhoe catchment — that’s the catchment with the dams:

So there is really nothing unprecedented about the current dry spell? Could the Bureau of Meteorology please correct the graph, or correct the Premier?

Update 22 August

Simon commented (see following thread) that the above graph looks different to the graph posted by Warwick at his site. Following is the graph posted by Warwick:

I made the error of assuming the graph Warwick sent me on the weekend was the same as the one he had posted at his blog. There are slightly differences after 1990, because as Warwick explains in the note at his website, “rainfall data is less than perfect, many stations close and an alternative has to be opened at another site, recordings can start then stop, there can be gaps in the data”.

In the graph I posted, Warwick had used values from neighbouring stations to see what a more complete record for the catchment looked like.

He has sent me the following comment tonight:

“If I can obtain a more complete catchment dataset I might spend a long day trying to correct these.

The Bureau of Meteorology and water utility have had years to publish a graph of catchment rain history if they wished to do so.

Clearly, it must not be perceived to be in their interests or they would have done so.

Likewise, I have never seen catchment rain history charts made by a water utility or the BoM for Perth, Sydney or Melbourne but maybe there are some I have not spotted.

Why is this when water supply issues are controversial in all our cities and all our dam water originates as rain.

I see the issue of the 2002 drought being raised and I show from the Australia wide Bureau of Meteorology high quality rain data that in 2002 there was a Great West Queensland drought but nothing nationwide to match the Federation drought.

…With respect to the claims of “worst drought in a whatever”, the criterion I was talking about was the definitions of serious and severe drought as on the Bureau of Meteorology website and as expressed in their maps with shades of pink to red. I have a small area of their latest 3 year map shown on my Brisbane page. Now I do not know what result you would get if that Bureau of Meteorology 36 month drought map series could be rolled back through 2000.

But do we expect policymakers to be making such definitive statements about data that is far from black and white and when the result is probably so line ball?“

When I look at the second graph I see regular wet periods with yearly averages around 1200mm (once as high as 1400mm) and there have also been regular dry periods with yearly averages around the 600mm (once as low as perhaps 450mm). We are currently in one of the dry periods with yearly averages in the 700-800mm range.

I received the following note from Paul Williams. It is an interesting critique of the use of bristlecone pines as an indication of past temperatures. In the note, Williams explains the pines may be a better proxy for carbon dioxide (CO2) than temperature. So, Williams concludes, the famous hockey stick graph may not be a ‘temperature hockey stick’, but rather a ‘CO2 Hockey Stick’:

“The “Hockey Stick” is the famous graph showing the results of studies done by Michael Mann, Raymond Bradley and Malcolm Hughes.

Mann, ME; Bradley, RS; Hughes, MK: ‘Global-scale temperature patterns
and climate forcing over the past six centuries’, NATURE |VOL 392 | 23 APRIL 1998

Mann, ME; Bradley, RS; Hughes, MK:‘Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations’, Geophysical Research Letters, Vol. 26, No. 6, 1999

These papers are often called MBH98/99.

The Hockey Stick depicts relatively constant temperatures from 1000AD up to 1900, (the shaft of the “hockey stick”), followed by a sharp rise in temperature, (the “blade”). This graph is used extensively to support the argument that humans are causing global warming by emitting large quantities of CO2 and other “greenhouse gasses” into the atmosphere.

Steve McIntyre and Ross McKitrick, (MM), challenged the statistical basis of MBH98/99, claiming that the conclusion, (that the 1990s were likely to have been the warmest years in the last millennium), was not supported by the data and statistical workings described in the papers.

Subsequently, MMs claims were verified by independent statistical analysis, as detailed in the Wegman Report and summarised in a Factsheet.

One of the aspects of MBH98/99 that the Wegman Report touched on, was the use of Bristlecone pines as indicators of temperature, or “temperature proxies”.

I have no expertise or qualifications in this field, but the use of bristlecones can be understood without knowing maths and statistics, and it is one of McIntyre and McKittrick’s main objections to the hockey stick, yet it gets little discussion compared to the obscure statistical arguments.

Bristlecones are pine trees living at altitudes up to about 4,000 metres in the dry mountains of California and Utah. Some of them are very old, over 4,000 years. They live in soils that are very low in nutrients, in areas with low precipitation. They have developed a survival system known as “dieback”. When a tree is stressed due to lack of nutrients or moisture, part of the tree will die, thus lowering the requirements for the nutrients or water for the tree as a whole. The tree survives by maintaining a strip of viable bark that carries nutrients to the surviving branches and canopy. Thus a large, old tree 18 metres tall, may be sustained by a 40cm strip of bark up one side.

Because of their great age, Bristlecones tend to dominate dendrochronologies, or climate records based on tree rings, that extend back in time for long periods. So they are very important in the data that MBH98/99 used to draw their conclusions. They are also important in some of the other studies that support the Hockey Stick. As the “Hockey Team” said in their post at Real Climate, “The Missing Piece at the Wegman Hearing”, in which they show that doing the statistics differently still leads to a Hockey Stick shape,

“Why doesn’t it make any difference? It’s because the PC analysis was used to encapsulate all of the statistically relevant information in the N. American tree ring network and so whatever patterns are in there they will always influence the final reconstruction.”

But is the pattern that’s in the Bristlecones a true reflection of temperature? As Wegman mentions, it is known that Bristlecones have reacted to increased atmospheric CO2 since about 1850. This CO2 fertilisation was allowed for in MBH99, but only by using the 19th century CO2 figures, as though the increase in CO2 that happened in the 20th century had no additional effect on the Bristlecones. This may in fact be correct, as they react more to CO2 increases at lower levels than at higher, but it is a point that needs to be verified.

It’s worth noting that MBH98 was the first “multi proxy” temperature reconstruction to include Bristlecones. Several of the following studies that support the Hockey Stick also use Bristlecones. Before MBH98, Bristlecones were not considered useful for temperature reconstructions.

Thus Bristlecones react strongly to atmospheric CO2 levels. They may be a better indicator of CO2 than of temperature. So the underlying pattern is a Hockey Stick, but not a temperature Hockey Stick, instead it is a CO2 Hockey Stick. And this pattern shows up in other studies that use them.

Disclaimer:

Much of this material I gleaned from Steve McIntyre’s site, Climate Audit.org. I could find literally no discussion about Bristlecones on Mann’s site, Real Climate.org.

Additional links:

Ross McKitrick’s presentation to the Australian APEC Study Group, 2005. A non-technical summary of the main issues that McIntyre and McKitrick have raised about the Hockey Stick.
http://www.uoguelph.ca/~rmckitri/research/McKitrick-hockeystick.pdf

Climate Audit website. (Steve McIntyre)
http://www.climateaudit.org

RealClimate website. (Michael Mann and others)
http://www.realclimate.org/

Bristlecones
http://www.sonic.net/bristlecone/home.html

Tree rings
http://web.utk.edu/~grissino/default.html“

Graham Young posted the following comment last night at an earlier blog post on climate change:

“Good to see we’ve moved on to the Hockey Stick. I find it interesting that while Enron’s auditor, Arthur Andersen, is virtually no more, because of its lack of oversight in “refereeing” (to borrow a scientific term to cover an accounting situation) the accounts of the company; and Enron’s highest executives were sent to jail, nothing much has happened to Mann et al, or their referees. Yet the Mann et al analysis has a lot in common with Enron.

While the original mathematical error was probably accidental, the perpetuation of it couldn’t have been, once the McIntyre and MacKittrick analysis had been released. Enron was a company that once made real profits, but got into modelling the future and counting the results of its models as profits, which it then reported as real, despite the evidence. In the real world, rather than the real climate world, that is called fraud.

Worse, Mann et al set up their blog to, amongst other things, essentially defame their critics. Likewise, Kenneth Lay et al did their level best to defame and discredit their critics.

The climate community seem to just regard this issue as just a bit of a dust-up (including many of the contributors to this blog’s comment box). In fact, it is far more serious than that, and the fact that reasonable people can have that attitude points to the serious crisis that there appears to be in some parts, at least, of the scientific community.

What has gone on here is criminal. Public monies have been directed in ways that they shouldn’t have been on the basis of this graph. The attempt to cover-up the problems is fraud. It’s about time that someone took legal action, assuming there is a law which makes this possible. If the law hasn’t envisaged this particular issue and neglected it, then one should be enacted to take accounts of these facts.

Of course, the irony is that the graph couldn’t have been correct in the first place as it didn’t take account of the medieval warm period, which we know from observation to have been much warmer than now. So why did so many otherwise intelligent people go along for the ride?

And don’t anyone tell me that the medieval warm period was a localised effect. If that was the case, where were the much colder counterbalancing areas in the reconstruction?”

The following comment by Paul Williams provides a different perspective on the question asked by Walter Starck a couple of days ago.

“I think we argue over AGW because there’s so many unanswered questions, such as:

1. Where are the climatic catastrophes we’ve been hearing about?

2. Why are the AGW proponents using dodgy statistics to bolster their case? (Even though they’ve now “moved on”)

3. Why are they proposing ineffective “solutions” for climate change, such as Kyoto?

4. Why do they constantly say the debate is over, when it obviously is not?

5. Why do they attack their opponents, rather than their opponents arguments?”

Clive Hamilton, Executive Director of The Australian Institute, has written a rather pointed piece for today’s Sydney Morning Herald suggesting that Tim Flannery, author of a recent book on global warming, is “a trump card” in Prime Minister John Howard’s “nuclear power play”. It also suggests that the government has bought off environment group the WWF:

“WWF (formerly the World Wide Fund for Nature) is the foremost of the friendly organisations. It is close to the Government, providing a stream of favourable commentary on its policies and bestowing several awards for the Government’s environmental achievements, including three “Gift to the Earth” awards, which the Environment Minister, Ian Campbell, displays in his office. In return, the Government has been generous, sending tens of millions to the fund for various programs.

The force behind the emergence of the organisation as the leading group backing the Government’s environment policy is the businessman Robert Purves. He has made a very large donation to WWF and is now its president.

Purves has drawn Tim Flannery into the orbit of conservative environmentalism by funding the preparation of Flannery’s book on climate change, The Weather Makers. … Purves is said to have spent $1 million promoting Flannery’s book, including costly backlit billboards outside Qantas Club lounges around the country.”

This is not the first time Clive Hamilton has thrown mud at WWF, his first shot was perhaps publication of a report titled ‘Taming The Panda’ just a couple of years ago.