By Pat Pepper
NCWQ Environment Adviser
Update on Great Barrier Reef (GBR): High sea surface temperatures continued into April resulting in unprecedented mass coral bleaching. This has been particularly severe in the Far Northern Region with aerial and underwater surveys showing substantial coral mortality in most inshore and midshell reefs. Thus it is of paramount importance that rising temperature be reduced. As the Chairman of the the Great Barrier Reef Marine Park Authority (GBRMPA), Dr Russel Reichelt, says this can only be achieved with global treaties which lower greenhouse gas emissions. At a regional level, the GBRMPA is working to build coral resiliency.
Projects reported previously such as those to improve water quality from agricultural catchments flowing into the GBR and curtail plagues of star fish are commendable and should help some reefs to recover but the global problem remains.
Cold Seam Gas (CSG): A recent dramatic video of a Greens Member of the NSW Upper Parliament setting light to methane seeping from the Condamine River has reignited the concern of the impact of CSG on groundwater. CSIRO researchers who have been studying methane seeps in the river since 2012 have stated that the seepage is unlikely to be caused by the CSG industry since methane had been known to leak out of naturally occurring fissures and there are at least four fissures in a 3km stretch of the Condamine River.
However the amount of gas seeping in that area has markedly increased in the past 12 months, a trend they suggest could be caused by a shift in sediment from the river bed, which would mean the gas was less dispersed, or could be the result of water that rushed into the alluvial aquifer during the 2011 Queensland floods slowly depleting, which would release the pressure and allow more methane to come to the surface. http://www.theguardian.com/environment/2016/apr/24/river-on-fire-in-greens-mps-video-is-natural-not-fracking-says-csiro
The Condamine River Alluvial Aquifer is an exceptional good and reliable groundwater resource which helps make the Darling Downs very valuable for agriculture. However it overlies the Walloon Coal Measures, a coal deposit which has been exploited for coal and, more recently, for CSG. In 2012, the Queensland government found that the chemistry of the gas from the Condamine River gas seep is consistent with a source in the Surat Basin. UNSW researchers, Bryce Kelly and Charlotte Iverarch, agree the Condamine River gas seep could be natural as the gas seep occurs in the river reach just after a sharp change in flow direction which is consistent with the presence of a major geological fault. However, in April 2016, they measured maximum methane concentrations of 595 parts per million (ppm) from a site of a presumably abandoned leaking coal exploration well just 2.5 km north of the Condamine River gas seep. Since the average natural background concentration of methane for the region is 1.79 ppm, the continuously high concentration indicated a direct path between the coal measures and the ground surface. There are hundreds of abandoned exploration wells in Queensland and an unknown number in the Chinchilla region. A poorly documented abandoned well closer to the Condamine River could account for the gas seeps. During CSG production large volumes of water are extracted depressurising the coal seam and shifting the methane so it can be recovered. Over decades the zone of depressurisation will extend away from the gas production well and slowly depressurise nearby areas. Connections between the coal measures targeted for gas extraction and the groundwater need to be understood. To date, only 17 out of hundreds of geological faults and no abandoned leaky wells have been incorporated into the regional groundwater model used to assess the impact of CSG production.
Depending on CSG production and groundwater use, these could conceivably contribute to lowering the groundwater levels of the Great Artesian Basin and the Condamine River (https://theconversation.com/river-on-fire-even-if-its-not-coal-seam-gas-we-should-still-be-concerned-58718, https://www.dnrm.qld.gov.au/__data/assets/pdf_file/0005/119669/condamine-river-gas-seep.pdf). This provides further evidence of the vital need for further research, groundwater monitoring and mapping of gas seeps prior to CSG.
Update on Climate Change: The historic United Nations Paris agreement on climate change has been signed by 175 countries. For the treaty to become law, 55% of countries need to ratify it, and at least 55% of global emissions to be represented by those accepting countries. The agreement sets crucial goals to limit global temperature increases, and specific goals in three areas – mitigation, adaptation and finance. Mitigation includes a long-term goal – early peaking, balancing emissions and sinks with emissions to be reduced from 55 gigatonnes (Gt) to 40Gt in 2030.A new global adaptation goal aims to increase countries’ adaptive capacity and resilience. There are also aims to achieve a finance increase to US$100 billion per year post 2020. While the Paris agreement, as it stands, will not solve the ongoing problem of climate change, if momentum can be created the target of preventing warming from exceeding 1.5 degrees might be achieved. With global temperatures already at one degree warmer, and emissions continuing as strongly as ever, the world has to act quickly to achieve this target. USA and China, the world's biggest emitters of climate changing greenhouse gases, have said they will ratify the Paris deal this year and are pushing for others to follow suit so the agreement could become operational by the end of this year.
In Australia, ratifying the Paris agreement means tabling the document in Parliament and submitting it for scrutiny by the Joint Standing Committee on Treaties. However, Australia has bipartisan support for the agreement, so no impediments are expected. http://www.abc.net.au/news/2016-04- 22/what-happens- after-this- paris-climate- deal-is- signed/7350506, https://theconversation.com/paris-set-a-benchmark-in-the-battle-against-climate-change-what-now-56934 http://www.abc.net.au/news/2016-05-06/ban-ki-moon- says-time-to-increase-climate-change-action/7389482?section=environment
A recent study which analysed 14 years of satellite data measuring the key climate variables of air temperature, water availability and cloud cover, has given a deeper insight into the impact of extreme events on ecosystems and which aspects of climate have been the most important in shaping different vegetation types around the world. The study confirmed that most of Australia was most sensitive to variability in water, rather than to temperature. But while there were areas of very high climate sensitivity in the east of Australia, the study showed inland ecosystems were among the world’s least sensitive to climate variability, particularly in terms of rainfall. http://www.abc.net.au/news/2016-02- 18/global-map- highlights-sensitivity-of-australian-
Sea-level rise, erosion and coastal flooding are some of the greatest challenges facing humanity from climate change. Coral islands are very dynamic landforms where waves and currents can change their shade by mobilising and depositing sand and gravel. If the sea level only rises 3-5 mm pa (global average 3mm pa), possibly islands could withstand the rise. https://theconversation.com/dynamic-atolls-give-hope-that-pacific-islands-can-defy-sea-rise-25436 However, in the Solomon Islands the sea has risen 7-10 mm pa since 1993. Some islands are exposed to higher wave energy. Of the 21 islands exposed, five completely disappeared and a further six islands eroded substantially. These rapid changes to shorelines have led to the relocation of several coastal communities that have inhabited these areas for generations Twelve islands in a low wave energy area experienced little noticeable change in shorelines despite being exposed to similar sea-level rise. https://theconversation.com/sea-level-rise-has-claimed-five-whole-islands-in-the-pacific-first-scientific-evidence-58511
Microplastics: The impact of microplastics on the marine environment, in particular the Great Barrier Reef has been reported previously. A team of Japanese researchers, led by Dr Shosuke Yoshida from the Kyoto Institute of Technology, have discovered a new species of bacteria that produces a plastic-eating enzyme. Hopefully this bacterium may help degrade some of the millions of tonnes of polyethylene terephthalate (PET) plastics dumped each year http://www.abc.net.au/news/2016-03- 11/plastic-eating- bacterium-can- break-down- pet/7238614
