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Hydrogen may play a crucial part in delivering a net zero emissions future. Currently, hydrogen production, storage, transport and utilisation are being explored to scope opportunities and to reduce barriers to market activation. One such barrier could be negative public response to hydrogen technologies. Previous research around socio-technical risks finds that public acceptance issues are particularly challenging for emerging, remote, technical, sensitive, uncertain or unfamiliar technologies - such as hydrogen. Thus, while the hydrogen value chain could offer a range of potential environmental, economic and social benefits, each will have perceived risks that could challenge the introduction and subsequent roll-out of hydrogen. These potential issues must be identified and managed so that the hydrogen sector can develop, adapt or respond appropriately. The geological storage of hydrogen could present challenges in terms of the perceived safety of the approach. Valuable lessons can be learned from international research and practice of CO2 and natural gas storage in geological formations (for carbon capture and storage, CCS, and for power, respectively). Here, we explore these learnings. We consider the similarities and differences between these technologies, and how these may affect perceived risks. We also reflect on lessons for effective communication and community engagement. We draw on this to present potential risks to the perceived safety of - and public acceptability of – the geological storage of hydrogen. One of the key lessons learned from CCS and natural gas storage is that progress is most effective when risk communication and public acceptability is considered from the early stages of technology development.

The CSIRO In-Situ Laboratory Project (ISL) is located in Western Australia and has two main objectives related to monitoring leaks from a CO2 storage complex by controlled-release experiments: 1) improving the monitorability of gaseous CO2 accumulations at intermediate depth, and 2) assessing the impact of faults on CO2 migration. A first test at the In-situ Lab has evaluated the ability to monitor and detect unwanted leakage of CO2 from a storage complex in a major fault zone. The ISL consists of three instrumented wells up to 400 m deep: 1) Harvey-2 used primarily for gaseous CO2 injection, 2) ISL OB-1, a fibreglass geophysical monitoring well with behind-casing instrumentation, and 3) a shallow (27 m) groundwater well for fluid sampling. A controlled-release test injected 38 tonnes of CO2 between 336-342 m depth in February 2019, and the gas was monitored by a wide range of downhole and surface monitoring technologies. CO2 reached the ISL OB-1 monitoring well (7 m away) after approximately 1.5 days and an injection volume of 5 tonnes. Evidence of arrival was determined by distributed temperature sensing and the CO2 plume was detected also by borehole seismic after injection of as little as 7 tonnes. Observations suggest that the fault zone did not alter the CO2 migration along bedding at the scale and depth of the experiment. No vertical CO2 migration was detected beyond the perforated injection interval; no notable changes were observed in groundwater quality or soil gas chemistry during and post injection. The early detection of significantly less than 38 tonnes of CO2 injected into the shallow subsurface demonstrates rapid and sensitive monitorability of potential leaks in the overburden of a commercial-scale storage project, prior to reaching shallow groundwater, soil zones or the atmosphere. The ISL is a unique and enduring research facility at which monitoring technologies will be further developed and tested for increasing public and regulator confidence in the ability to detect potential CO2 leakage at shallow to intermediate depth.

Legislation and guidelines developed for Carbon Capture and Storage (CCS) have set performance requirements to minimize leakage risk, and to quantify and remediate any leaks that arise. For compliance it is necessary to have a comprehensive understanding of the possible spread, fate and impacts of any leaked CO 2, and the ability to detect and quantify any CO 2 seepage into marine or terrestrial environments. Over the past decade, a number of field scale CO 2 release experiments have been conducted around the world to address many of the uncertainties regarding the characteristics of near-surface expression of CO 2 in terms of the impact and quantitation of CO 2 leaks. In these experiments, either free phase or dissolved CO 2 was injected and released into the shallow subsurface so as to artificially simulate a CO 2 leak into the near-surface environment. The experiments differ in a number of ways, from the geological conditions, surface environments, injection rates and experimental set-up - including the injection and monitoring strategy. These experiments have provided abundant information to aid in the development of our scientific understanding of environmental impacts of CO 2 while assessing state of the art monitoring techniques. We collated a global dataset of field-scale shallow (depths < ~25 m) controlled CO 2 release experiments. The dataset includes 14 different field experiment locations, of which nine intended to release CO 2 to the surface, and the remaining sites intended for CO 2 to remain in the shallow subsurface. Several release experiments have been conducted at half of these sites, and so in total, 41 different CO 2 release tests have taken place at the 14 sites in our dataset. We scrutinized our dataset to establish: (i) the range of experimental approaches and settings explored to date (such as the environment, subsurface conditions, injection strategy and whether gaseous or dissolved CO 2 were injected and in what quantities); (ii) the range of CO 2 injection and surface release rates at these experiments; (iii) the collective learnings about the surface and subsurface manifestation of the CO 2 release, the spread and fate of the CO 2, rates of CO 2 flux to surface, and methods of measuring these; (iv) the strengths and limitations of current approaches for detecting and quantifying CO 2. This allowed us to highlight where uncertainties remain and identify knowledge gaps that future experiments should seek to address. Further, drawing on the collective experiences, we have identified common issues or complications which future CO 2 release experiments can learn from.

No abstract available.

Site selection for the geological storage of CO2 for long timespans requires an understanding of the controls on containment, migration, and surface seepage of subsurface CO2 fluids. Evidence of natural CO2 migration from depth to the surface is documented at 270 sites from Italy, a prolific CO2 province. Previous studies indicate that CO2 delivery to and from buried structures that host CO2 accumulations is fault controlled but competing controls on the CO2 flow pathways affect the location and style of CO2 release. Here, we conduct a meta-analysis using a novel geospatial approach to statistically determine the relationship between the geological setting and structures and the CO2 seep spatial distribution and characteristics (morphological type, flux, and temperature) in Central Italy. We find that seep distribution differs on two spatial scales corresponding to the geological setting. On large scales (>5 km), seeps are isotropically distributed and align with regional structures such as anticlines, decollements, and extensional faults. On local scales (

One approach to decarbonising the cement and construction industry is to replace Portland cement systems with lower carbon alternatives that have suitable properties. We show that seven cementitious binders comprised of metakaolin, silica fume and nano-silica have improved thermal performance compared with Portland cement and we calculate the full CO2 emissions associated with manufacture and transport of each binder for the first time. Due to their high porosity, the thermal conductivity of these novel cements is 58–90% lower than Portland cement, and we show that a thin layer (20 mm), up to 80% thinner than standard insulating materials, is enough to bring energy emissions in domestic construction into line with the UK 2013 Building Regulations. Carbon emissions in domestic construction can be reduced by c. 20–50% and these cementitious binders are able to be recycled, unlike traditional insulation materials.

One approach to decarbonising the cement and construction industry is to replace ordinary Portland cement (OPC) with lower carbon alternatives that have suitable properties. We show that seven innovative cementitious binders comprised of metakaolin, silica fume and nano-silica have improved thermal performance compared with OPC and we calculate the full CO2 emissions associated with manufacture and transport of each binder for the first time. Due to their high porosity, the thermal conductivity of the novel cements is 58–90% lower than OPC, and we show that a thin layer (20 mm), up to 80% lower than standard insulating materials, is enough to bring energy emissions in domestic construction into line with 2013 Building Regulations. Carbon emissions in domestic construction can be reduced by 20–50% and these cementitious binders are able to be recycled, unlike traditional insulation materials.

The study of natural analogues can inform the long-term performance security of engineered CO2 storage. There are natural CO2 reservoirs and CO2 seeps in Italy. Here, we study nine reservoirs and establish which are sealed or are leaking CO2 to surface. Their characteristics are compared to elucidate which conditions control CO2 leakage. All of the case studies would fail current CO2 storage site selection criteria, although only two leak CO2 to surface. The factors found to systematically affect seal performance are overburden geopressure and proximity to modern extensional faults. Amongst our case studies, the sealing reservoirs show elevated overburden geopressure whereas the leaking reservoirs do not. Since the leaking reservoirs are located within

Does the curriculum content of Biblical Archaeology as being taught at the University of South Africa (UNISA) develop the skills necessary for, and expected by the students and the market place? What motivates students to register for post graduate studies in religion? How can these questions be answered with scientific rigour? One could expect that these students would like to deepen their faith. Empirical research into student motivation for studying Biblical Archaeology, however, paints another picture - suggesting a pilgrimage of discovery. This is one of the interesting results that can be obtained through a simple empirical survey questionnaire. By posing nine questions, over 100 pieces of information can be obtained. Historically, research methodologies employed in Biblical Studies have been based on the phenomenological paradigm. By employing a positivist approach, the results of research conducted into student motivation for studying Biblical Archaeology at UNISA, provide far deeper insights into student profiles, motivations and expectations. Teaching staff, not only in Biblical Archaeology, need to be equipped to understand this information which can be obtained through empirical investigation. Seen from this angle, Biblical Archaeology is not merely about teaching how to turn stones -it is to be taught to turn life into a meaningful journey through the past, while keeping an eye on the present, and it could be done by including course material such as aspects of tourism in a space where people of all convictions can participate in the journey.