Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Archives for August 2008

Causal Linkage between Carbon Dioxide and Global Warming (Part 3): Causal Criteria Still Wanting

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The Australian government is planning to introduce an emission’s trading scheme, also described as a carbon pollution reduction scheme, on the basis that that carbon dioxide from the burning of fossil fuels is contributing to dangerous global warming.

Many people assume that such a drastic action is premised on good evidence establishing a proven causal link between anthropogenic carbon dioxide and global warming.

For example, when establishing causality between an environmental pollutant and an effect on an animal species, scientists would be expect to establish not only a correlation between the presence of the pollutant and an effect (for example an illness in the population), but be also able to demonstrate a dose-response relationship and describe a credible toxicological basis for the proposed mechanism linking the proposed cause and effect.

Interestingly while anthropogenic carbon dioxide is now considered to be one of the worst pollutants,
there does not appear to be a body of work establishing the basic criteria for a claimed causal relationship between the purported pollutant, anthropogenic carbon dioxide, and the claimed effect, global warming; atleast not outside of the United Nations Intergovernmental Panel on Climate Change reports. In particular there does not appear to be a body of work published in reputable scientific journals.

Furthermore, much of the science underpinning the need for a proposed carbon pollution reduction scheme in Australia appears to be based on the claim of a scientific consensus and the observation that there have been increasing levels of atmospheric carbon dioxide over the last 150 years and over this period temperatures have also been generally increasing.

I posted a note on my blog and John Quiggin’s blog on Sunday evening suggesting this deficiency and requesting “research results that have been published in reputable scientific journals that: 1. examine the causal link between anthropogenic carbon dioxide and warming, and 2. quantify the extent of the warming from anthropogenic carbon dioxide.”

Several papers were suggested to me, I believe in good faith, as fulfilling this criteria including a paper entitled ‘Causes of Climate Change Over the Past 1,000 Years’ by Thomas Crowley (14 July 2000, Vol 289, Science).

I was disappointed with the paper when I read it this afternoon. The paper essentially compares output from a reconstruction of past climate with output from an energy balance climate model. In other words, the paper looks at the fit between output from two models. So the paper is about correlation not causation.

But most disappointing, the reconstruction of past climate in the Crowley paper is based on the work of Michael Mann and colleagues which has been the source of much controversy and many believe completely discredited by a report from a team of statisticians led by Edward Wegman, chair of the National Academy of Sciences’ (NAS) Committee on Applied and Theoretical Statistics, assembled at the request of U.S. Rep. Joe Barton and U.S. Rep. Ed Whitfield .

Indeed what has become known as the hockey stick controversy is illustrative of the nature of climate science in what Aynsley Kellow, Professor and Head, School of Government, University of Tasmania, has described as post-normal science with an extensive reliance upon models and the potential for significant manipulation of their source data.

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Part 1, Causal Linkage between Carbon Dioxide and Global Warming:
Part 2, Causal Linkage between Carbon Dioxide and Global Warming (Part 2): Still Searching for Evidence

Conflict of Interest for Chairman of UK Environment Committee

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Tim Yeo used his casting vote as chairman of the all-party Environmental Audit Select Committee to push through a report, published last week, which backed the decision by Alistair Darling, the Chancellor, that new, higher rates of vehicle excise duty (VED) rates should apply to previously-purchased cars.

The committee had been evenly split, with three Labour MPs supporting the Government line while three Tory and Lib Dem MPs opposed it, arguing that the move amounted to retrospective taxation. Mr Yeo broke the deadlock by siding with the Labour MPs.

He is paid £40,000 a year as non-executive chairman of Eco City Vehicles Plc, a company which plans to market a hybrid car which would qualify for low rates of VED under the new tax regime, due to its low carbon emissions.

Telegraph.co.uk: Tory MP Tim Yeo in conflict-of-interest row over car tax report

A spoonful of enviro-sugar helps the atmospheric medicine go down

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In her 16th July 2008 media release, GREEN PAPER ON CARBON POLLUTION REDUCTION SCHEME RELEASED, Senator, the Hon. Penny Wong, Minister for Climate Change and Water, stated that:

“Climate change threatens … icons like the Great Barrier Reef, the Kakadu wetlands and the multi billion dollar tourism industries they support.”

The selection and juxtaposition of these two icons is, at the very least, strategically interesting. The Great Barrier Reef is widely celebrated as one of the natural wonders of the world, epitomising environmental importance for Australians. Kakadu, in a similar vein, is resplendent with fauna and flora and resounds of antiquity and Aboriginal spirituality. It is a logical companion to the Reef and particularly if the Minister’s intention was to capture the breadth and diversity of Australia’s environmental concerns.

However, the Reef is thought to be around a half-million years old and quite obviously has endured temperature variations throughout this period. With an even greater perseverance, Kakadu is believed to have formed around 140 million years ago, with the prominent escarpment wall forming sea cliffs and the Arnhem Land plateau a flat land above the sea.

Yet, despite these environmental assets enduring against the ravages of turbulent climate variation, their imminent environmental collapse is foreshadowed alongside the devastating implication of multi-billion dollar economic losses, unless dramatic changes are implemented as outlined in the Federal Government’s draft Carbon Pollution Reduction Scheme.

But what of other environmental icons, like the World Heritage-listed Daintree Rainforest? Surely it is even more vulnerable to these forecast catastrophic climate changes? Being coastal, it is more proximal to inundation than Kakadu, it is more primitive, has a far richer biodiversity and endemism and attracts more than twice the annual visitation and expenditure.

Perhaps its ecological interaction with the contiguous Great Barrier Reef is spatially less inclusive of the broader environmental diversity between the Reef and Kakadu. Nevertheless, localised carbon pollution should be more of a concern in the Daintree rainforest with its greater vulnerabilities and visitation, as well as its more abundant income-earning performance. Not that Kakadu should be under-valued, but it seems entirely incongruous that for all the urgency for this necessary intervention, that nothing is being done to protect the Daintree rainforest from carbon pollution emitted from hundreds of concurrently running engine generators.

It has been conservatively estimated that the federal government will raise ten billion dollars in 2010 from the sale of permits to emit greenhouse gases. Every cent of this estimated bounty will purportedly be used to help Australian households and businesses adjust to the emissions trading scheme and to invest in clean energy options.

Perhaps the federal Government might be persuaded to embrace the Daintree World Heritage rainforest as a priority pilot project to remove the unnecessary emissions of so many generators.

Causal Linkage between Carbon Dioxide and Global Warming (Part 2): Still Searching for Evidence

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On Sunday a colleague and I discussed the general issue of correlation versus causation in science. He suggested that 1. There must be a body of work establishing a causal link between anthropogenic carbon dioxide and warming, and also 2. Some work that quantifies the extent of the warming from the anthropogenic carbon dioxide. He assumed as much because our government, the Australian government, is planning major perturbation to our economic system on the basis that carbon dioxide from the burning of fossil fuels is contributing to dangerous global warming. He assumed that the Australian government would not undertake such an action lightly, indeed that such an action would be premised on good evidence establishing a proven causal link between anthropogenic carbon dioxide and global warming. I replied that I was not so sure.

He said he would do a search of the scientific literature on Monday. I said it would be interesting to compare what he turned up from this systematic search of library databases with a few random requests on the internet.

So, Sunday evening I posted a note at my blog, at John Quiggin’s blog and at a yahoo climate science group of mostly so-called climate change skeptics.

Perhaps not surprisingly one of the first to claim that a body of work existed was John Quiggin; a well known climate alarmist. Professor Quiggin went as far as to claim that there are “hundreds of papers on both the causal link and the question of sensitivity” but could only cite a few papers which dabble with the issue of sensitivity later in that blog thread.

By early Monday evening (when I started writing this blog post) the thread at Professor Quiggin’s blog had thrown up only three papers that I thought could potentially provide a causal link and a quantification of the extent of warming. Interestingly one of them was published as long ago as 1938. I had listed the papers earlier in the day at the threads at both Professor Quiggin’s and my blogs to see if other papers were put forward in preference to these, but they weren’t. The papers are:
1. Callendar, G.S., 1938. The artificial production of carbon dioxide and its influence on temperature. Q. J. R. Meteorol. Soc., Vol 64, 223–237.
2. Hofmann, D.J., J. H. Butler, E. J . Dlugokencky, J . W. Elkins, K. Masarie, S. A. Montzka and P. Tans, 2006. The role of carbon dioxide in climate forcing from 1979 to 2004: Introduction of the Annual Greenhouse Gas Index, Tellus B, Vol 58, 614-619.
3. Crowley, T. 2000. Causes of Climate Change Over the Past 1000 Years. Science Vol 289: 270-277.

The Hofmann et al. paper initially looked the most promising to me, is available on the internet (click here) and is the first that I shall consider. (I plan to post comment on the Crowley or Callendar paper tomorrow.)

While the title of the Hofmann et al paper does suggest a “role” is established for carbon dioxide as a forcing/warming agent, in fact it is just assumed in the body of the paper.

The authors simply taken a set of gases (including carbon dioxide) and ascribed an effect: climate forcing. They do not demonstrate a mechanism, or even shown a correlation, between levels of anthropogenic carbon dioxide and global warming.

So, I shall have to conclude that this paper fails the criteria (1. There must be a body of work establishing a causal link between anthropogenic carbon dioxide and warming, and also 2. Some work that quantifies the extent of the warming from the anthropogenic carbon dioxide).

Reading the paper I was struck by the extent to which the authors assume that the increase in atmospheric levels of carbon dioxide since 1750 is primarily a result of “anthropogenic emissions” without explaining why.

There is an extensive scientific literature discussing the notion of causation and how this might be established, for example between environmental stressors and observed effects in natural systems. This literature emphasises that where there are potential alternative explanations for an observed correlation these should be considered.

In the case of carbon dioxide and global warming, Lance Endersbee (former Dean of Engineering and Pro-Vice Chancellor of Monash University) has suggested a direct physical relation between increasingly levels of atmospheric carbon dioxide and increasingly average global sea surface temperatures over the last few decades (click here) suggesting the carbon dioxide is being released from the warming oceans.

Thanks to everyone who has posted and/or emailed papers and comment following my three random requests on the internet last night.

I intend this to be just the second in the series. I shall endeavour to consider the submissions beginning with those that appear the most promising and as a series of blog posts. Of course guest posts, and with alternative opinions, are welcome.

A Critical Review of ‘Green Carbon: The Role of Natural Forests in Carbon Storage’

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Last week the Australian National University released a report** on “Green Carbon” claiming that un-logged native forests store three times more carbon than previously reported and this prompted a demand by The Wilderness Society for an urgent end to logging of the carbon dense native forests in New South Wales, Victoria and Tasmania.

Alan Ashbarry, a Tasmanian with an interest in the social and economic benefit of value adding native forest timber from sustainable forestry and a member of Timber Communities Australia, has sent me his critique of the report.

It begins:

The report was funded by the Wilderness Society as part of its campaigns against the harvesting of native forest of high political value. This campaign includes opposing Tasmania’s approved pulp mill as it will use pulp wood from native forests at a time when the Wilderness society claims that their “carbon storage is critically important to combat climate change”.

So is it not surprising that the report recommends the banning of all industrial logging in Australia’s south eastern native forests.

This means closing down the native forest timber industry in Tasmania, Victoria and Southern New South Wales and stopping the pulp mill.

In the ultimate irony, if the industry is shut down, it is likely that Australia will import timber and paper products from tropical forests in developing counties as alternatives for the wood products created by sustainable forestry in these areas.

It is these tropical forests that are most at risk and are the target of the United Nation’s REDD program. This program aims to reduce emissions from deforestation or degradation of forests in the developing world.

According to data from the United Nations the REDD program does not target sustainable forestry in Australia.

All official statistics and reports show that deforestation has virtually stopped in Australia and all forest harvesting/ management is undertaken and measured against international criteria for sustainable management.

Unlike the Wilderness Society, the UN’s Intergovernmental panel of Climate Change (IPCC) recognises the value of our forest sector explaining:

“In the long term, a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks, while producing an annual sustained yield of timber, fibre or energy from the forest, will generate the largest sustained mitigation benefit”

But what about the new report published by the ANU and funded by the Wilderness Society? How robust is the claim that un-logged native forests store three times more carbon than previously stated in Australian government reports and by internal climate change experts?

The report itself states: “A technical paper that details the source data, the methods used and the full results is being prepared for a scientific journal.”

In the absence of this data, I checked their maths and found the report also failed the common sense test.

The ANU report has used a new model to estimate the carbon in our forests, a model that is completely at odds with studies undertaken by the Australian Greenhouse Office, Professor Peter Attiwill, Forestry Tasmania, MBAC, and the Cooperative Research Centre for Greenhouse accounting and they have significantly higher results than modelling by the Australian National University in 2003 and 2006.

The report’s lead author, Professor Brendan Mackey, who is a Wilderness Society volunteer on their Wild Country panel, last year in The Age demanded logging must be stopped to solve the global warming problem.

In The Age article he claimed “One hectare of mature, tall, wet forest can store the equivalent of 5500 tonnes of carbon dioxide” this is the equivalent of the large figure of total 1500 tonnes Carbon per hectare stored in the biomass and the soil [The conversion factor used for C/CO2 is 12/44 (0.273)].

Now this new ANU report in which he is lead author claims that forests “can store three times more carbon than scientists previously thought.”

The model used in the ANU report somewhat quaintly colour codes the carbon throughout the World: black is for charcoal, grey from fossil fuel, green is carbon stored in the biosphere, brown is carbon in “industrialised forests” and blue is carbon in the atmosphere and oceans. As green carbon is defined by the report as carbon sequestered through photosynthesis and stored in natural forests, the report can then ignore all that carbon that is stored in timber products from managed forests. This is extraordinary given that the carbon in managed forests is also manufactured through photosynthesis, yes even the carbon stored in the “brown” trees!

The ANU report selects only 14.5 million hectares from Australia’s forest estate of over 147 million hectares.
The new model created for this report relies on data of the ‘gross primary productivity’ and the report states: “The value of GPP used was the maximum annual value for the period from 1 July 2000 to 30 June 2005 (the maximum was used in order to exclude periods of major disturbance such as the 2003 bushfires).” This statement begs the question of why would you want to exclude bush fires surely this is “green” carbon.

Thus the model is all about potential not reality, and states on page 7:

“The difference in carbon stocks between our estimates and the IPCC default values is the result of us using local data collected from natural forests not disturbed by logging. Our estimates therefore reflect the carbon carrying capacity of the natural forests.”

The ANU report argues that “If logging in native eucalypt forests was halted, the carbon stored in the intact forests would be protected and the degraded forests would be able to regrow their carbon stocks to their natural carbon carrying capacity.”

Until this report it has mostly just been the forest sector that has stated the forest re-grows after harvest and can maintain both biological diversity and carbon carrying capacity.

The report authors then make a series of assumptions to determine the carbon sequestration potential of the logged forest area.

The report claims that an average carbon carrying potential of 360 t C ha-1 of biomass carbon (living plus dead biomass above the ground). It also claims the highest biomass carbon stocks, with an average of more than 1200 t C ha-1 and maximum of over 2,000 t C ha-1 are in the mountain ash (Eucalyptus regnans) forest in the Central Highlands of Victoria and Tasmania.

These are the areas of highest political value and have constantly been in the middle of the debate about forest management for the last decade or two.

It is these figures that clearly demonstrate that the model fails basic maths and common sense. If the carbon volumes are converted to the actual volume of trees, it means that there would be trees growing on trees!
Carbon density of eucalypt wood is about 0.325 t C/ m3, this means at 2,000 t C ha-1, this is 6,153.84 m3 of wood, say 6,150 m3 per ha. If only half of this could be considered the timber available to the forest sector(exclude branches, litter, rotting wood, stumps), then this wood equates to a volume of logs of about 3,000m3/ha.
Therefore in an average coupe of 50 ha this represents 150,000m3 of log, it means based on the model that two average size coupes will produce over 300,000 m3 of log.

To compare just how big a figure this is, Forestry Tasmania has a legislated requirement to supply the whole of Tasmania’s saw milling industry 300,000 m3 of saw logs each year from the 1.5 million hectares it sustainably manages!

In 2006-07 Forestry Tasmania harvested over 11,500 ha of native forest for a harvest of 301,526 m3 of sawlog, 283,880 m3 veneer and peeler hardwood and 2,136,687 tonnes of pulpwood. By approximating a tonne of pulp to 1.5 cubic metre this would be about 330 m3 per ha or 16,500 m3 per average coupe.

Even The Wilderness Society used a completely different figure of only 225 tonnes pulp wood per hectare, when calculating the impact of the approved pulp mill on Native forests. Even allowing for harvesting residues this is a tiny fraction of the new model’s figures.

The report fails the common sense test but it was published by a reputable university and has been given all the credibility of an independent scientific report by the mainstream media including the ABC.

The Wilderness Society and the ANU chose to release the report to the media rather than first publish it in a scientific journal subject to peer review. Now the report is likely to be used to lobby the United Nation committee that current forest practices degrade the forest. This lobbying attempt is just after their failure to convince UNESCO over wild allegations about the Tasmanian World Heritage Area.

Until the data and the calculations supporting this report have been subject to full independent scrutiny, the reports status must be considered just another claim in the ‘war of words’ on forestry.

Alan Ashbarry
Tasmania
www.tasmaniapulpmill.info

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** The report’s title is rather long: Green Carbon: The role of natural forests in carbon storage
Part 1. A green carbon account of Australia’s south-eastern Eucalypt forests, and policy implications
Authors are: Brendan G. Mackey, Heather Keith, Sandra L. Berry and David B. Lindenmayer
Published by: The Fenner School of Environment & Society, The Australian National University
And you can download it from: http://epress.anu.edu.au/green_carbon/pdf_instructions.html

We Aren’t Responsible for Rising Atmospheric Carbon Dioxide: A Note from Alan Siddons

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The following chart is largely self-explanatory:

Alan Siddons ver 3.jpg

Red: The actual rise of atmospheric CO2 from 1966 to 2006
Pink: The actual rise of human emissions within that 40 year timeframe (starting point at 321 ppm for comparison)
Blue: Human emissions multiplied by 24.41 to parallel atmospheric CO2 growth
Black: The human emissions slope as it would be if CO2 had stagnated in the atmosphere
Gray line: Accumulating atmospheric human emissions with a yearly retention rate of 0.56 — meaning that 44% is absorbed yearly, which contradicts the assertion that CO2 remains in the atmosphere for hundreds or thousands of years.

Alan Siddons
Holden, Massachusetts

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Data sources are from the US government’s Carbon Dioxide Information Analysis Center (CDIAC):
http://cdiac.ornl.gov/ftp/trends/co2/maunaloa.co2
http://cdiac.ornl.gov/ftp/ndp030/global.1751_2004.ems

But here’s the trick: How do you convert gigatons of carbon into ppm so you can compare the human and atmospheric trend? Well, CDIAC informs you: Divide gigatons by 2.13.
http://cdiac.ornl.gov/faq.html#Q6