Putting the Great Barrier Reef marine cloud brightening experiment into context

Guest post by Kerryn Brent, University of Adelaide;  Jeffrey McGee, University of Tasmania; Jan McDonald, University of Tasmania; Manon Simon, University of Tasmania. The authors are members of the Australian Forum for Climate Intervention Governance (AFCIG), which aims to promote climate intervention governance research in Australia and the Southern Hemisphere.  / 13 May 2020

[The views of guest post authors are their own. C2G does not necessarily endorse the opinions stated in guest posts. We do, however, encourage a constructive conversation involving multiple viewpoints and voices.]

The Great Barrier Reef (GBR) is a world heritage-listed natural wonder, but is suffering badly from coral bleaching exacerbated by climate change.

In what is hoped to be a first step towards mitigating future GBR coral bleaching events, Australian scientists conducted the first outdoor marine cloud brightening (MCB) experiment in late March. The purpose of this experiment was to test a delivery mechanism comprised of 100 high-pressure nozzles that can spray nano-sized sea-salt particles into the air above the reef. At the time this experiment was conducted, leading reef scientists announced that the GBR was undergoing the third mass coral bleaching event in five years.

MCB involves spraying sea salt particles into clouds above the ocean to enhance the number of water droplets and hence the amount of sunlight reflected by the cloud. Previously described as a form of solar radiation management (SRM) geoengineering [1], MCB was initially proposed as a means of cooling temperatures at a global scale to offset rising temperatures associated with climate change. However, MCB also has potential to be used at a local or regional scale for cooling effects that might protect high value but vulnerable natural assets from climate change impacts, such as polar regions and coral reefs.

In the past, proposals to field-test SRM technology have generated considerable interest and controversy from the scientific community, press and public (recent examples include the Stratospheric Particle Injection for Climate Engineering (SPICE) project and the Stratospheric Controlled Perturbation Experiment (SCoPEx)). As Jesse Reynolds has already remarked, this GBR experiment has largely gone unnoticed. Although, in the last few days, the field test has attracted some belated attention from civil society, and a reply to this from Reynolds.

To better understand why this acknowledged outdoor SRM experiment appears to have passed largely without controversy, this post explains the particular context in which the GBR experiment took place.

1. Protecting a Nationally-Iconic Area from Heat Stress

The GBR is the world’s largest coral reef system and Australia’s first world heritage listed site. It is a national icon, as a site of natural beauty and the basis for a AUD$29 billion per year tourist industry. Concerns have been mounting over the impacts of coral bleaching on the reef and the GBR MCB test was part of a suite of ‘interventions’ that are being developed to protect the GBR from the impacts of climate change. The frequency and severity of coral bleaching events is likely to increase as global mean surface temperatures continue to rise, and scientists have recommended limiting global warming to less than 1.2°C to protect the biodiversity of the GBR. Limiting global warming to 1.5°C, as agreed by States under the 2015 Paris Agreement, will not be enough to save the GBR. It is understood in Australia that further action is necessary to protect the GBR and help it adapt to the impacts of climate change.

MCB is one of many interventions that the Federal and State government funded ‘Reef Restoration and Adaptation Program (RRAP)’ is developing to protect the GBR and enhance its resilience in the face of climate change. The RRAP is a partnership between government and non-government research organisations, including Australia’s national science agency (CSIRO), the government body responsible for managing the GBR (The Great Barrier Reef Marine Park Authority), a leading public institution for tropical marine research (Australian Institute of Marine Science), and other Australian universities. The RRAP is investigating a wide range of interventions, including the use of genetic enhanced organisms to improve the tolerance of corals to climate change, and constructing artificial reef structures.

MCB belongs to a broader category of ‘cooling and shading interventions’. These aim to prevent coral stress during heatwaves by lessening the amount of sunlight that warms the waters of the reef, or by mixing cooler water with warmer water to directly lower water temperatures. Interestingly, the RRAP also considered investigating stratospheric aerosol injection and ocean fertilisation as part of its initial Concept Feasibility Study, but decided not to pursue these proposals, as they were thought to carry too much risk.

2. Outdoor experimentation was not a big surprise

It has been clear from the outset that the RRAP program would include outdoor experimentation of interventions on the GBR, including MCB. Small-scale field testing of a polymer surface ‘sunscreen’ was approved and conducted in 2019, under the specific rules governing research within the Great Barrier Reef Marine Park. The Reef Trust Partnership (which funds the RRAP) released a two-year work plan in 2019 which budgeted AUD$1.6 million in 2020 for proof of concept and key systems engineering for SRM for 2020. The report forecast a further AUD$62.3 million for further R&D over the next five years, with the expected outcome being the development of large-scale SRM intervention methods for the reef. In October 2019, the RRAP published detailed investment case- and concept-feasibility study reports. These reports identified MCB and related interventions, such as producing fog or mist, as research priorities.

3. Program includes early governance and community engagement research

At first glance, this experiment appears to challenge some important ‘home truths’ about geoengineering research governance. Most importantly, there has been a widely-held view that outdoor experimentation, and certainly deployment, of SRM technologies should not proceed without specific governance arrangements being in place first. This is not to say that the experiment took place in a governance vacuum: it was conducted under existing rules of Australian domestic environmental law that apply to activities on the GBR.[2]

Furthermore, the RRAP has acknowledged the importance of governance to the success of their program as a whole. It has produced a detailed report on the regulatory environment in which MCB and other interventions will be conducted in, with a view to improving the regulation and accountability of the program. It has produced a further report regarding the internal governance of the RRAP. Furthermore, the program has published findings from early public engagement exercises, including with reef stakeholders and indigenous owners. This early research aimed to assess social acceptability of different interventions and inform further stakeholder engagement activities.

MCB is part of a suite of interventions for the reef, and from this perspective it appears logical to research and develop a governance framework that targets the program as a whole, rather than individual technologies. It is also understandable that governance focus on reef protection, since that is the mandate of the funding. But this focus on the GBR does miss the wider implications of MCB for SRM interventions and thus suggests a missed opportunity for SRM governance.[3]

4. Australia has a long history of terrestrial cloud seeding

The GBR experiment bears many similarities to land-based cloud seeding activities, which have been conducted for over 70 years by Australian governments. Australia’s history of cloud seeding, including the use of salt particles, may further explain why this experiment was relatively uncontroversial. The CSIRO began investigating cloud seeding for rainfall enhancement in the late 1940’s.[4] Since then, most Australian states have experimented with cloud seeding,[5] with long-term programs being conducted in recent years in Tasmania and New South Wales. From 2007-09, a research program was carried out in Queensland to test the use of salt particles to enhance rainfall. While cloud-seeding has long been an accepted part of Australian hydro-electricity research and development, most states that use cloud seeding have in fact enacted specific laws to govern its use. The fact that such legislation was considered necessary suggests that the unique characteristics and wider implications of MCB may be overlooked in a governance regime focussed only on the GBR.

5. Public focused on other issues

Finally, it is worth pointing out that this experiment occurred during a major health and economic crisis, with COVID-19 and associated government response measures dominating the public’s attention. The experiment also occurred after a long summer of catastrophic bushfires. Environmentalists, politicians and the public at large in Australia are still dealing with the aftermath of these fires, including through a Royal Commission. The significance of an experiment that might have attracted greater attention during ‘normal’ times pales in comparison to these more immediate issues.

Lessons for SRM governance

The March 2020 MCB experiment on the GBR was conducted in a unique context, but there may nevertheless be lessons that we can learn from it for future SRM field-tests.

First, this experiment indicates that SRM research for regional deployment with a targeted objective may be more socially acceptable, especially for protecting iconic and economically valuable natural assets.

Second, there may be further advantages if the technique being tested is similar to existing practices, such as cloud seeding.

Finally, this experiment and future activities under the RRAP will provide SRM governance researchers with a new case study that does not involve the development of SRM-specific governance mechanisms. Instead, it provides an example of outdoor experimentation proceeding under existing domestic laws, on the understanding that governance will be developed as part of a broader GBR intervention framework. While this contains the scope of the governance task for now, it risks engendering societal acceptance of SRM by stealth.

Dr. Kerryn Brent is a lecturer in climate change and environmental law at Adelaide Law School. She is the deputy director of AFCIG and her research focuses on the governance of carbon dioxide removal and solar radiation management technologies.

Associate Professor Jeffrey McGee is the Director of the Australian Forum for Climate Intervention at University of Tasmania and researches on the governance of marine and Antarctic geoengineering.

Professor Jan McDonald researches environmental and climate law, with a focus on adaptation to the impacts of climate change and geoengineering governance.

Manon Simon is a PhD candidate at University of Tasmania conducting research on the relevance of weather modification laws and policies for solar geoengineering governance.

[1] NB: C2G uses the term solar radiation modification. To learn more about climate-altering techniques that may be deployed in the marine environment, click here.
[2] See Pedro Fidelman et al ‘Regulatory implications of coral reef restoration and adaptation under a changing climate’ (2019) 100 Environmental Science and Policy 221.
[3] Jan McDonald et al, ‘Governing geoengineering research for the Great Barrier Reef’ (2019) 19(7) Climate Policy 801.
[4] EB Kraus and P Squires, ‘Experiments on the Stimulation of Clouds to Produce Rain’ (1947) 159(4041) Nature 489.
[5] Brian F Ryan and Warren D King, ‘A Critical Review of the Australian Experience in Cloud Seeding’ (1997) 78(2) Bulletin of the American Meteorological Society 239.

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