By Dr. John L. Black (June 21, 2025) in consultation with Professor Robert G Bednarik
Summary
The Western Australian and Commonwealth governments approved in November 2024-May 2025 the Woodside Energy North-West Shelp Project Extension Proposal to continue operations until 2070 on Murujuga in northwest Western Australia. The Project will emit over 4 billion tonnes of carbon dioxide equivalents over its lifespan and around 10,000 tonnes of nitrogen dioxide annually.
Murujuga is the site of the world’s largest rock art gallery showing continuously for potentially 50,000 years the culture and spiritual beliefs of humankind. The priceless and irreplaceable petroglyphs were created by the Yaburura people until the 1886 massacres. Once damaged, it takes thousands of years for petroglyphs to be restored by the rock varnish forming microbes.
Murujuga is sacred for the Original Australians. The government approvals were based partly on the second report from the industry funded, government and Murujuga Aboriginal Corporation administered Murujuga Rock Art Monitoring Program (MRAMP). The western Australian government claimed ‘The research indicates that the current levels of the pollutants of most concern for the rock art are lower than the interim guideline levels’.
An evaluation of the MRAMP report shows that current levels of pollutants have already damaged the outer ferromanganese rock varnish and weathering rind, both essential for preservation of the petroglyphs. The MRAMP report either provides evidence for this damage, or the interpretation of results can be challenged.
The discussion points are listed:
1) The report shows substantial porosity of the weathering rind of Murujuga rocks near the industrial areas and the Dampier township. Porosity was most closely related to nitrogen dioxide concentration across the Dampier Archipelago and the authors claim the porosity ‘may represent anthropogenic impact’. Rainwater containing the acidic emissions and dry acid deposits will penetrate the pores on the rock surface into the existing weathering rind and gradually increases the size of existing pores to ultimately disintegrate the weathering rind zone with loss of the surface rock varnish and the petroglyphs.
2) The MRAMP claim that rainfall is now neutral to alkaline is contrary to previous studies using similar methodology and the MRAMP result is likely due to sea/dust contamination, largely because of the location of the rain receptors.
3) MRAMP showed that the main acidic gases on Murujuga, nitrogen dioxide and sulphur dioxide, will develop pores in base igneous rock, which is more resistant to damage than the outer rock coatings, suggesting that these acidic emissions will be damaging the rock varnish and weathering rind, essential for preservation of the petroglyphs.
4) MRAMP measured an increase in rock surface pH from between pH 4 and 5 for measurement campaigns 2, 3, 4 and 5 but rising to around pH 6 in campaigns 6 and 7, which can be explained by a change in methodology. For the latter two campaigns an ionic strength adjuster (ISA) was use while making pH measurements. An ISA will increase measured pH by about 1 pH unit in high ionic solutions such as the surface of Murujuga rocks because H+ ions attached to other compounds, particularly Na+ and -SiO-, are released into solution, which will increase H+ concentration and therefore rock surface pH measurement.
5) The Cyanobacteria, responsible for concentrating manganese during rock varnish formation were shown to be absent from the industrial areas with high acid gas concentrations but not in other regions. This observation shows that, in the non-industrial areas, the rock varnish is still being formed, but not in the industrial area. Finally, recent independent research outside MRAMP, has shown that the manganese content of the rock varnish, essential for its preservation, in rocks collected in 2022 is less than half the concentration in a rock sample collected from a similar site near industry in 1994.
These findings prove that emissions are currently degrading the Murujuga petroglyphs beyond natural rates. The rock art will be destroyed near industry unless acidic emissions are eliminated. Technologies exist to reduce acidic industrial emissions to zero.
With continuing government approvals for industry on Murujuga and little restriction on acidic emissions, where is the justice for the massacred Yaburara people? The intergenerational trauma continues throughout the generations.
Introduction
In December 2024, the Western Australian government approved an application from the natural gas processing company, Woodside Energy Ltd, for the North-West Shelf Project Extension Proposal to continue operations until 2070 of the Karratha Gas Plant situated on Murujuga, in northwest Western Australia (Whitby 2024). Murujuga is part of the Dampier Archipelago which contains the world’s largest gallery of an estimated one million petroglyphs (McDonald and Veth 2011).
The petroglyphs are globally unique displaying continuously for potentially 20,000 to 50,000 years or more the activities, culture and spiritual beliefs of humankind until the 1868 massacres of their creators, the Yaburara people (Gara 1983; Lorblanchet 1983, 1992: Bednarik 2006; McDonald and Veth 2009; Mulvaney 2022). For the original Australians Murujuga is sacred.
The Western Australian government decision to extend the operation of the Karratha Gas Plant until 2070 was made despite 727 formal appeals by the public against the proposal on the grounds of the huge greenhouse emissions and continued damage to the petroglyphs from the thousands of tonnes of acidic nitrogen dioxide released annually and which deposits on the rock surfaces (Whitby 2024).
The ‘License to Operate’ granted to Woodside Energy following the decision to approve the North-West Shelf Project Extension Proposal included clause 3 on Air Quality with Section 3- 1 stating the Air Quality Outcome is:
(1) to ensure that no air emissions from the proposal have an adverse impact accelerating the weathering of rock art within Murujuga beyond natural rates.’
The supporting documentation (Whitby 2024: 8-9) adds ‘that it is expected that the MRAMP (Murujuga Rock Art Monitoring Program) will provide reliable information on changes and trends in the condition of the rock art and whether anthropogenic emissions are accelerating the natural weathering, alteration, or degradation of the rock art.’
Final approval for the Woodside Energy North-West Shelf Project Extension Proposal relied on a decision from the Federal Government Minister for the Environment under the Environmental Protection Biodiversity Conservation Act 1999 because non-industrial sections of the Dampier Archipelago were declared National Heritage Listed in 2007.
The MRAMP (2024), report of around 800 pages, although completed in late 2024, was finally released by the Western Australian government on the afternoon of Friday 23 May 2025. On the following Wednesday 28 May, the Federal Minister for the Environment gave approval with undisclosed conditions for the Woodside North-West Shelf Proposal to proceed based partly on the MRAMP report.
This decision was made by the Minister despite being informed on 24 May 2025 that the World Heritage listing would not proceed until the government could among other recommendations:
i) Ensure the total removal of degrading acidic emissions, currently impacting upon the petroglyphs of the Murujuga Cultural Landscape; and ii) Prevent any further industrial development adjacent to, and within, the Murujuga Cultural Landscape (ICOMOS 2025).
Murujuga Rock Art Monitoring Program
Although most of the research reported by MRAMP (2024) is substantive and adds to knowledge on the impacts of industrial emissions on Murujuga petroglyphs, several methods employed are inappropriate, some interpretations dubious and have resulted in controversial conclusions in the Report Summary (DWER 2025) and subsequent press releases.
Second year Report Summary
The summary of the research ‘Murujuga Rock Art Monitoring Program: Research Summary Year 2’ released by (DWER 2025: 3-5) makes the following claims:
i) ‘The acid rain/deposition theory proposed by earlier researchers is not supported by the data from this program’;
ii) ‘Measurements of rainfall and deposition over the past two years are neutral or slightly alkaline’;
iii) ‘Rock surface pH is not a reliable indicator of rock degradation’;
iv) ‘The research indicates that the current levels of the pollutants of most concern for the rock art are lower than the interim guideline levels’.
The first claim is based on the second claim that rainfall and depositions across Murujuga are neutral to alkaline, which is outside previous measurements of rainfall pH on Murujuga sites and is a result of the location of the rainfall receptors as described below.
Nevertheless, regarding the first claim, there is an abundance of world literature that shows the ferromanganese rock varnish in desert environments such as Murujuga is highly sensitive to rock surface acidity with the manganese compounds being dissolved when pH falls below neutral (Dorn 2024; Black 2025).
For the third claim, there is clear evidence to show that the pH of rock surfaces can vary. The rock surface pH measured will change with chloride from sea water, the washing of dissolved acids and dissolved minerals from the rock varnish during rain, the release of ammonia into the atmosphere, structure of the rock surface, time to equilibrium during rock surface measurements, ambient temperature, and operator techniques (MacLeod 2005; MacLeod and Fish 2021; MRAMP 2023).
Nevertheless, when rock surface pH is below 6-6.5, there is strong evidence that the ferromanganese rock surface layer starts to be dissolved (Bednarik, 2007; Dorn 2024; Black 2025).
For example, Lefkowitz et al. (2013) showed that the lattice structure of the magnesium rich birnessite in rock varnish breaks down when rock surface pH is less than 7. Furthermore, Bednarik (1979, 2002) observed that rock varnish was not present on Murujuga rocks where birds perch and where the mean pH was 5.9 across 30 of these sites. Loss of the rock varnish leads to decimation of the petroglyphs.
The fourth claim that implies current levels of industrial emissions can continue without an impact on the Murujuga petroglyphs is not sustainable as shown below in the evaluation of the MRAMP (2024) report.
Evaluation of the MRAMP 2024 report
The MRAMP 2024 report contains evidence that industrial emissions are currently damaging the rock surfaces on Murujuga and the rock art. There are five specific areas of the MRACP (2024) report discussed in detail.
Elevated porosity of the weathering rind
The MRAMP 2024 report shows substantial porosity of the weathering rind of Murujuga rocks and that it varies with location of the rocks (Figure 1. MRAMP 2024 Report Figure 7.6- 8).
The location for greatest porosity of the rock weathering rind is near the industrial areas and the Dampier township. The authors show that the variation in porosity is most closely related to nitrogen oxide (NOx) concentration across the Dampier Archipelago (Report Figure 7.11-14).
As an example, Figure 2 shows the distribution of measured NOx for December 2022, with the highest concentration over the industrial area.
Figure 1. Reproduction of Figure 7.6-8 from MRAMP (2024) report showing the distribution of weathering rind porosity across the Dampier Archipelago.
Figure 2. Reproduction of the December 2022 measurement of NOx, as nitrogen dioxide, distribution (μg/m3) from MRAMP (2024) Figure 7.11-14.
The authors (Aubrey et al. 2025: iv, 285–295) observed that the association of weathering rind porosity and distribution of NOx ‘may represent anthropogenic impact’.
However, the authors attribute the increased porosity to the former Dampier power station. This attribution to an earlier industry is not sustainable because the power station operated from 1966 to 1986 with heavy fuel oil and increasing output over those years to approximately 8000 tonnes NOx annually (Report p 633).
From 1986 to 2010, the power station used natural gas with a total NOx output of a little over 2000 tonnes annually.
Secondly, porosity of the weathering rind is also close to the current petrochemical industrial complex well away from the old Dampier power station. Industry provided information to the National Pollution Inventory show NOx emissions ranging from approximately 8,000 to 16,000 tonnes annually from 2001/02 to 2021/22, where the Karratha Onshore Gas Plant refers to the Woodside North-West Shelf gas processing facility (Figure 3).
The substantial drop in NOx emissions by shown the Karratha Onshore Gas Plant in 2013/14 was due to a change in the methods Woodside used for the Pollution Inventory entry. In the Karratha Gas Plant Annual Environmental Report – July 2018 To June 2019, Woodside state that ‘If the new method was applied retrospectively, the data points prior to the 2013/14 period in Fig 4.1 would decrease by approximately 40%’.
The information contained in the National Pollutant Inventory is provided voluntarily and is not validated by any authority.
The following historical occurrence illustrates this anomaly well. Two days before a conference of international air quality scientists and rock art conservators was to be held in Dampier, Woodside announced on 26 March 2003 that it had for many years made a major error in calculating the emissions of NOx at its Karratha Onshore Gas Plant and conceded NOx emissions were about twice as great as listed in the National Pollutant Inventory.
Figure 3. NOx emissions as reported annually by industry on Murujuga obtained from National Pollution Inventory in March 2023. Reproduced from Black (2025).
The MRAMP (2024) report provides clear evidence that the porosity developed in the Murujuga rock weathering rind is closely associated with the emissions of industrial acidic gases. Each time the rock surface is soaked by rainwater containing the acidic emissions, acids from the dry deposits and the rain penetrate the pores on the ferromanganese rock surface into the existing weathering rind pores and gradually increases their size.
Ultimately, this process leads to the physical disintegration of the weathering rind zone and, with it, the loss of the surface rock varnish and the petroglyphs.
Degradation of base rock by NO2 and SO2 in climate chambers
The climate chamber studies were conducted with the base rocks found on Murujuga and not with the ferromanganese rock varnish or with the weathering rind, which are both more sensitive to acidic dissolution than base rock.
Significantly, the base rocks, when exposed to increasing concentrations of SO2 and NO2, developed observable pores in the rock structure. The MRAMP (2024: 439) report concludes ‘The chamber studies have confirmed a mechanism by which rock surfaces exposed to air pollution could undergo an increase in porosity, as observed in field samples. This has been confirmed chemically (through analysis of leachate) and physically (through high resolution pre- and postexposure analysis of minerals via imaging).’
Thus, the chamber studies provide further evidence that industrial pollutants on Murujuga are capable of seriously damaging the rocks and therefore rock art on Murujuga.
Reason for measured rainwater and dust deposition pH being neutral to alkaline
The MRAMP (2024) report shows that the pH of rainfall and dust deposition were neutral to alkaline, ranging from pH 7 to 8.7 at different sites (Figure 4: MRAMP 2024 Figure 7.10- 25: 344).
Clean unpolluted rain has a pH 5.6 due to carbon dioxide from air being dissolved in the rain to form carbonic acid, whereas acid rain has a pH of 4.5 or below (US EPA 2025).
There are other measurements of rain pH on Murujuga and Dampier that do not correspond with the MRAMP results.
First, as part of the Murujuga Rock Art Conservation Project at the University of Western Australia, Dr Ken Mulvaney collected rain while falling into sterile glass containers in seven rainfall events near Dampier between April and September 2022. The average pH of the collected rain was 5.89, with a range from pH 5.43-6.46. These rain samples were collected within about 1 km of the iron ore train line and port facility and may have included small amounts of iron ore dust.
Secondly, the rain measuring system used by MRAMP (2024) was a static collection over approximately four weeks using a three bucked system that prevented evaporation. A similar static single bucket system was used by Gillett (2008) to measure rain constituents including pH over ‘about’ 30 days in 2024/05 for twenty measurements at 5 sites and in 2007/08 for 24 measurements at six sites previously used by CSIRO on the Murujuga industrial area and close to industry. Only one site at Parker Point was close to the sea.
The mean acid-base value for rain measured by Gillett in 2002/05 was pH 5.04 (range pH 4.34-6.78) and for rain measured in 2007/08 was pH 5.29 (range pH 4.77- 6.60). The two highest values recorded were at the Parker Point location close to the sea. The rain pH measures obtained by Gillett in 2004/05 are similar to those reported for 2004 by Bednarik (2007) at pH ⁓4.6.
Figure 4. Historical measurements of rain pH on the Dampier Archipelago. Red dots from Bednarik (2007) and numbered sites from the MRAMP (2024) report page 344.
These previous rain pH measurements can provide an explanation why the MRAMP (2024) measured values were unusually high for natural rain. The seven sites used by MRAMP (2024) to measured rain and dust deposition are shown as red circles in the map of Murujuga (Figure 5). All sites are located close to the sea. Sites AQ-09, AQ-02 and AQ-14 were a little further from the coast and had the lower rain pH values of all sites measured at pH 7.0-7.4.
Figure 5. Sites used by MRAMP (2024) to measure rain pH and dust deposition are the red circled locations.
The MRAMP (2024: 344) report provides a clear explanation for the reason their rain pH values were high by stating ‘Rainfall pH above 7 is usually considered to be due to salt/sea spray or alkaline dust/clay’. The pH of sea water is between 7.7 and 8.3 with an average of 8.1 (US EPA 2025), while the pH of moist iron ore dust is 7.1-8.5 (Soltani et al. 2021).
The MRAMP (2024) results suggest that the method of rain collection and the locations of the collection sites are the primary reasons for the high pH values recorded because it allowed deposition of sea salt and dust on the collecting system. Although this explanation was clearly stated in the MRAMP (2024) report, the authors unjustifiably use these high rain pH measurements to claim that the ‘acidification’ hypothesis of Bednarik (2007) and Smith et al. (2022) that the rock varnish and weathering rind on Murujuga is being degraded by low pH rock surfaces is not supported by the MRAMP studies.
Reason for measured rock surface pH being high in measurement campaigns 6 and 7
MRAMP (2024) measured rock surface pH on seven occasions with mean values being above 6 in campaign 1, between pH 4 and 5 for campaigns 2, 3, 4 and 5 and rising again to around pH 6 in campaigns 6 and 7 as shown (Figure 6). MRAMP disregard the results from campaign 1 because of technical reasons. There was a major difference in the experimental technique used for campaigns 6 and 7 compared with earlier measurement campaigns, where an ionic strength adjuster (ISA) was use while making pH measurements.
The MRAMP (2024) report did not include a comparison in the rock surface pH values obtained with or without the ISA. This failure was a major technical oversight in the experimental procedures, particularly when a comparison with and without ISA was made for chlorine measurements. There is ample evidence that shows the addition of ISA will substantially increase the pH of measured high ionic solutions by as much as 1 pH unit (Wiesner et al. 2006). This increase in measured pH with ISA occurs because H+ ions that were attached to other compounds, particularly Na+ and -SiO-, are released into solution, increasing H+ concentration and the measured pH value.
Thus, the reason that the pH values from rock surfaces in the MRAMP campaigns 6 and 7 is likely due to the change in experimental technique and not due to environmental changes.
Figure 6. Measurements of rock surface pH by MRACP for the seven campaigns. From MRAMP (2024) Figure 7.4-1; p 254.
Absence of cyanobacteria near the gas treatment areas
MRAMP (2024) report their findings on the presence of microbial species on rocks and an investigation into an association between organism density and the observed increase in porosity of the weathering rind of rocks near the industrial area (MRAMP 2024, Figure 8.2-3).
The analysis showed that Geodermatophilus genus was more abundant in areas of high rock porosity and Chroococcidiopsidaceae genus, which contains the phylum Cyanobacteria, was more abundant in regions with low porosity. The low abundance of Cyanobacteria near the industrial areas on Murujuga (Figure 7) is an important observation relating to the effects of industrial emissions on the long-term preservation of the Murujuga petroglyphs.
The photosynthetic Chroococcidiopsis Cyanobacteria organisms are critical for the formation of rock varnish in desert environments (Culotta and Wildeman 2021; Lingappa et al. 2021; Chaddha et al. 2024).
These organisms are crucial for concentrating manganese and iron from the environment by up to 100-fold to form a protective sheath to allow them to survive the harsh desert conditions. The protective outer sheath of the Cyanobacteria disintegrates when the organisms die to form rock varnish at the extraordinary slow rate of 1-40 μm in 1000 years (Liu and Broecker 2000; Dorn 2020). The Cyanobacteria evolved in an extremely low nutrient desert environment and obtained the nitrogen they needed for metabolism directly from the air and their carbohydrates through photosynthesis. The rock varnish forming Cyanobacteria are highly resistant to desiccation, ultra-violet radiation, high salt concentrations and high temperatures (Bothe 2019). The distribution of Cyanobacteria at regions away from industry suggests that rock varnish is still being formed at these sites, but not in the industrial areas.
Furthermore, the MRAMP (2024) redundancy analysis (Figure 8.2- 3: 416) shows higher concentrations of manganese, iron and aluminium (all essential compounds in rock varnish) to be closely associated with high presence of Cyanobacteria and inversely related to porosity in the weathering rind.
This observation is further evidence that emissions from industry have ceased the formation of rock varnish increased porosity and will be accelerating the rate of varnish and weathering rind degradation and therefore longevity of the petroglyphs.
Figure 7. Reproduction of MEAMP (2024) Figure 7-8-2 showing the relative abundance (%) of the microbial phylum Cyanobacteria, which is predominantly responsible for rock varnish formation.
Impact of industrial emissions on Murujuga petroglyphs
The MRAMP (2024) report confirms that both the ferromanganese rock varnish layer, through decreased presence of the varnish forming Cyanobacteria, and the weathering rind, through increased porosity, are currently being degraded in areas that are in proximity of the petrochemical industries on Murujuga.
Accelerated degradation of the rock varnish and increased porosity weathering rind will inevitably lead to destruction of the Murujuga petroglyphs.
The evidence presented in the MRAMP report shows clearly that Clause 3, Section 3-1 (1) on Air Quality ‘to ensure that no air emissions from the proposal have an adverse impact accelerating the weathering of rock art within Murujuga beyond natural rates’ of the Woodside Energy Licence to Operate the North West Shelf facility has been contravened and that acidic emissions are currently degrading the Murujuga petroglyphs beyond natural rates.
A major failure of the MRAMP was the lack of comparison with rock samples collected prior to industrialisation of the area with the samples collected from 2022.
By contrast, Neumann (2025), as part of the Western Australian University Murujuga Rock Art Conservation Project, obtained a sample of granophyre rock collected by Bednarik in 1994 from near the Woodside North-West Shelf gas treatment facility for comparison with rocks collected in 2022 from a similar area. Neumann (2025) examined section of the rock varnish with differing colour for manganese content.
Analysis of black, manganese rich varnish sections of samples collected in 1994, showed that its MnO contents ranged from 12 to 20 wt. %, and were substantially higher than the amounts of only 3.01 to 7.97 wt. % in the samples collected in 2022 (Neumann 2025: 55). Similarly, for the orange lower manganese rich varnish regions, the MnO content of rock collected in 1994 was 10–11 wt. %, while the corresponding 2022 samples yielded concentrations as low as 0.48 wt. %. The Fe2O3 content was only slightly higher in the 1994 sample than on the surface of the 2022 samples.
However, the Fe-Mn ratios were substantially lower in the 1994 sample than for all measurements on the recently collected samples, indicating a significant loss on manganese from the rock varnish of Murujuga rocks over the last 28 years.
Neumann (2025) also superimposed hyperspectral Raman images for manganese on electron micrographs of images of thin cross-sections of the rock varnish sample from granophyre rock collected in 1994 with those of granophyre rock collected in 2022 (Figure 8).
The 1994 sample to the left of Figure 8 showed clear lamination of manganese compounds as expected in unaltered rock varnish, a depth of varnish of about 12 μm, with only one obvious dark porous spot.
In contrast, the 2022 granophyre sample to the right of Figure 8 showed no obvious lamination with very few manganese compounds present. The depth of the 2022 sample varnish was only about 3 μm and there were many dark porous areas.
The Neumann (2025) results show that the manganese content of Murujuga rock surfaces has been significantly depleted due to increased dissolution rates over past years. Neumann’s proposition that Murujuga rock varnish weathering rates most likely already accelerated due to the lower pH of the rainwater for several decades fits with the observations from the MRAMP observations of reduced varnish forming Cyanobacteria and increased weathering rind porosity in areas adjacent to the Murujuga industrial area.
Figure 8. The hyperspectral Raman image for manganese is superimposed on the electron microscope image and its location is marked by a rectangle in the element distribution images. Colour coding of the element distribution images varies from red for high to blue for low abundances. The left picture shows the cross section of the 1994 sample with the rock surface to the right and the right panel shows a 2022 sample with no clear lamination, little manganese remaining and a substantial area free of matter. From Neumann (2025).
The findings of Neumann (2025) reinforce evidence that has been available for many years from the research conducted by MacLeod (2005) that manganese and iron are leached from the surface of Murujuga rocks at a logarithmic rate (ten times per unit pH change) as pH falls from the measured values of pH 5.4 to pH 4.2 (Figure 9). The pH range observed by MacLeod was similar to that measured by MRAMP (2024) before the addition of the ionic strength adjuster to their measurements.
Figure 9. Relationship between rock surface pH and concentration (PM, log10 ppm) of iron and manganese minerals in the washings from rocks on Murujuga in 2004. The slope of therelationships indicates the increase in solubility of rock varnish compounds as acidity increases. From Black et al. (2017c).
The summary report of MRAMP (2024) research prepared by the Western Australian DWER (2025: 5) states that: ‘The research indicates that the current levels of the pollutants of most concern for the rock art are lower than the interim guideline levels’. This statement is clearly not supported by the evidence presented from a comprehensive evaluation of the MRAMP (2024) report.
The chief statistician for the project, Adrian Baddeley, wrote to DWER outlining his concerns about the way one of the graphs in the scientific report had been handled. In the report delivered to DWER, the graph included a green line (representing an early warning threshold) was deleted from the published summary version of the report against Baddeley’s wishes (Shine 2025).
The short version of the 800-page report grossly misrepresented the main findings of the MRAMP research by not concluding as the report shows that the rock varnish and the weathering rind of Murujuga rocks containing petroglyphs within the industrial area are already being degraded beyond natural rates. The longevity of the petroglyphs is being reduced now.
Actions required to preserve Murujuga petroglyphs for future generations
The scientific evidence is strong that restoration of the ferromanganese rock varnish cannot occur unless the rock surface pH is at 6.5 or above, as summarised by Black (2025), because the manganese compounds are dissolved once pH falls below 6.5.
Furthermore, the Cyanobacteria primarily responsible for creation of the rock varnish do so at the rate of 1–40 μm in 1000 years. Clearly, it would take 100s of years for the damage that has already been caused by industry to the rock varnish and weathering rind to be restored. The only solution to prevent further damage to the rock varnish and weathering ring, and therefore the petroglyphs on Murujuga, is to reduce acidic gas emissions to zero. Technologies are available to achieve such an outcome.
Yara International have developed Selective Catalytic Reduction (SCR) systems which reduce nitrogen oxides emissions from individual industrial outlets by 98% (Yara International 2025). Placing several of the SCR systems in series for each nitrogen dioxide venting outlet from all industries on Murujuga would reduce nitrogen dioxide emissions to zero.
According to the NOPSEMA (2025) report accepting the Scarborough offshore gas environmental plan, Woodside Energy considered the use of the SCR system and a wet scrubber system to reduce nitrogen dioxide emissions but rejected their use on the basis that ‘the cost of implementation grossly outweighed the environmental benefits at this point in time’ (NOPSEMA 2025: 8).
This is an astonishing revelation by Woodside Energy implying that the profits for the company are more important than saving the world unique heritage in Murujuga petroglyphs from certain destruction.
All nitrogen dioxide on Murujuga is produced by burning natural gas at high temperatures in air that contains nitrogen. The heat produced is used for a wide range of industrial processes including the liquification of natural gas for export. However, the heat required for these industrial processes could also be produced from electricity, which can be generated away from Murujuga, and prevent the emissions of nitrogen dioxide in the vicinity of the petroglyphs.
Surely, electrification of these heat producing processes should be a condition imposed by governments on the Murujuga industries to prevent further damage to the petroglyphs. Although this suggestion has been made in many submissions to governments, it has not yet been made a requirement in new Licenses or Works Approvals for industries on Murujuga.
Injustice for the Yaburara people continues
The Western Australian and Federal governments by their refusal to acknowledge the evidence presented in the MRAMP (2024) report that the Murujuga petroglyphs are currently being degraded above natural rates and allowing industrial acidic emissions to continue until 2070 are knowingly approving the continual demise of potentially 50,000 years of human heritage of world significance.
The 1868 massacres of the Yaburara creators of the petroglyphs and their connection to Murujuga are deeply embedded in the memories of the Aboriginal custodians of the land today. This lack of current government action to preserve the Murujuga petroglyphs continues the awful wrongness perpetrated by non-Aboriginal people on the indigenous population.
The intergenerational trauma continues today through so many generations.
Where is the justice for the Yaburara people?
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