Australian Climate Research Articles

Simulation-based study on the role of green roof settings on energy demand reduction in seven Australian climate zones

Simulation-based study on the role of green roof settings on energy demand reduction in seven Australian climate zones

Greenhouse Gas Removal in Australian Climate Law: A Positive Role for Negative Emissions

Greenhouse Gas Removal in Australian Climate Law: A Positive Role for Negative Emissions

Trooping the (School) Colour

Trooping the (School) Colour

Sizing of Hybrid Supercapacitors and Lithium-Ion Batteries for Green Hydrogen Production from PV in the Australian Climate

Instead of storing the energy produced by photovoltaic panels in batteries for later use to power electric loads, green hydrogen can also be produced and used in transportation, heating, and as a natural gas alternative. Green hydrogen is produced in a process called electrolysis. Generally, the electrolyser can generate hydrogen from a fluctuating power supply such as renewables. However, due to the startup time of the electrolyser and electrolyser degradation accelerated by multiple shutdowns, an idle mode is required. When in idle mode, the electrolyser uses 10% of the rated electrolyser load. An energy management system (EMS) shall be applied, where a storage technology such as a lithium-ion capacitor or lithium-ion battery is used. This paper uses a state-machine EMS of PV microgrid for green hydrogen production and energy storage to manage the hydrogen production during the morning from solar power and in the night using the stored energy in the energy storage, which is sized for different scenarios using a lithium-ion capacitor and lithium-ion battery. The mission profile and life expectancy of the lithium-ion capacitor and lithium-ion battery are evaluated considering the system’s local irradiance and temperature conditions in the Australian climate. A tradeoff between storage size and cutoffs of hydrogen production as variables of the cost function is evaluated for different scenarios. The lithium-ion capacitor and lithium-ion battery are compared for each tested scenario for an optimum lifetime. It was found that a lithium-ion battery on average is 140% oversized compared to a lithium-ion capacitor, but a lithium-ion capacitor has a smaller remaining capacity of 80.2% after ten years of operation due to its higher calendar aging, while LiB has 86%. It was also noticed that LiB is more affected by cycling aging while LiC is affected by calendar aging. However, the average internal resistance after 10 years for the lithium-ion capacitor is 264% of the initial internal resistance, while for lithium-ion battery is 346%, making lithium-ion capacitor a better candidate for energy storage if it is used for grid regulation, as it requires maintaining a lower internal resistance over the lifetime of the storage.

Social media messaging by climate action NGOs: a case study of the 2019–2020 Australian Black Summer bushfires

Abstract Researchers are increasingly examining discourses associated with climate change and extreme weather events across different communication channels. However, further research is needed to examine how environmental non-governmental organizations (NGOs) frame extreme weather events and their relationship to climate change on social media platforms. This is an important topic as these groups play a significant role communicating science and driving environmental action. Here, we examine how Australian climate action NGOs framed the relationship of the 2019–2020 Black Summer bushfires to climate change on Twitter/X. Analyzing 2,077 bushfire-related tweets from a sample of 102 climate group accounts through manual content analysis, we found that these groups frequently linked bushfires with climate change, representing 59% of their bushfire-related tweets during the period of the fires. Forty-two percent of tweets mentioned climate change without describing how it relates to bushfires; 16% described specifically how climate change influences the frequency and intensity of bushfires; and only 1% suggested inaccurately that climate change causes bushfires to occur. Fifteen percent of tweets discussed risk factors beyond climate change that influence bushfire impacts, such as firefighting, emergency responses, hazard reduction, and community vulnerabilities. Only seven accounts mentioned an extreme event attribution study of the Black Summer fires. Based on these findings, we discuss opportunities and challenges of climate science communication in the extreme weather context, and describe promising directions for future research.

Comparative analysis of Australian climate change and COVID-19 vaccine audience segments shows climate skeptics can be vaccine enthusiasts

Denialism and the spreading of misinformation have occurred regarding both climate change and COVID-19, delaying uptake of urgent actions. Audience segmentation analysis identifies audience subgroups likely to have similar responses to messaging, and is a valuable tool for effective campaigns encouraging critical behaviors in both contexts. This study compared audience segmentations based on a representative sample of 1054 Australians. One segmentation was based on the ‘Global Warming’s Six Americas’ online SASSY tool. The second segmentation applied the Theory of Planned Behavior and found five distinct COVID-19 vaccine segments. Both studies showed those most concerned and those most skeptical in the climate change segmentation tended to be in more enthusiastic COVID-19 vaccine segments, while those in the center on climate change were more skeptical on COVID-19 vaccines. Differences identified relating to age, gender, and political views may be explained by a combination of the specific nature and histories of these issues. These findings have implications for effective communication on science and health issues across diverse disciplines.

Australian climate warming: observed change from 1850 and global temperature targets

Mean annual temperature is often used as a benchmark for monitoring climate change and as an indicator of its potential impacts. The Paris Agreement of 2015 aims to keep the global average temperature well below 2°C above pre-industrial levels, with a preferred limit of 1.5°C. Therefore, there is interest in understanding and examining regional temperature change using this framework of ‘global warming levels’, as well as through emissions pathways and time horizons. To apply the global warming level framework regionally, we need to quantify regional warming from the late 19th century to today, and to future periods where the warming levels are reached. Here we supplement reliable observations from 1910 with early historical datasets currently available back to 1860 and the latest set of global climate model simulations from CMIP5/CMIP6 to examine the past and future warming of Australia from the 1850–1900 baseline commonly used as a proxy for pre-industrial conditions. We find that Australia warmed by ~1.6°C between 1850–1900 and 2011–2020 (with uncertainty unlikely to substantially exceed ±0.3°C). This warming is a ratio of ~1.4 times the ~1.1°C global warming over that time, and in line with observed global land average warming. Projections for global warming levels are also quantified and suggest future warming of slightly less than the observed ratio to date, at ~1.0–1.3 for all future global warming levels. We also find that to reliably examine regional warming under the emissions pathway framework using the latest climate models from CMIP6, appropriate weights to the ensemble members are required. Once these weights are applied, results are similar to CMIP5.

Evaluation of seasonal teleconnections to remote drivers of Australian rainfall in CMIP5 and CMIP6 models

This study describes how coupled climate models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) simulate the primary climate drivers that affect Australian climate, and their seasonal relationship to Australian rainfall, namely the El Niño–Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and the Southern Annular Mode (SAM). As results from the earlier generation of models (CMIP5) are still in use, the CMIP6 multi-model mean teleconnections between climate drivers and seasonal Australian rainfall are compared to CMIP5. Collectively, an improvement is found in CMIP6 relative to CMIP5 in the representation of the relationship between ENSO and IOD events and Australia’s springtime rainfall. Overall, CMIP6 models are also able to reproduce the asymmetric relationship between ENSO and eastern Australian rainfall, which exhibits a more robust signal during La Niña than during El Niño years. Both CMIP5 and CMIP6 models are also generally able to capture the stronger relationship between Central Pacific La Niñas, compared to Eastern Pacific La Niñas. However, the large spread in model-to-model behaviour, and among ensemble members, remains a source of uncertainty. Although CMIP6 models have improved in their representation of SAM variability, the simulated relationship between SAM and Australian rainfall has not materially improved. Additionally, this study is accompanied by an extensive Appendix in which each model’s ENSO, IOD and SAM seasonal teleconnection patterns to rainfall are presented and ranked.

Consolidating historical instrumental observations in southern Australia for assessing pre-industrial weather and climate variability

Human-induced climate change has resulted in long-term drying trends across southern Australia, particularly during the cool season, with the most pronounced impacts observed in the southwest since the 1970s. Although these trends have been linked to changes in large-scale atmospheric circulation features, the limited number of daily weather datasets that extend into the pre-industrial period have so far prevented an assessment of the long-term context of synoptic-level changes associated with global warming. To address this need, we present the development of the longest sub-daily atmospheric pressure, temperature and rainfall records for Australia beginning in 1830. We first consolidate a range of historical observations from the two southern Australian cities of Perth and Adelaide. After assessing the quality and homogeneity of these records, we verify their ability to capture the weather and climate features produced by the Southern Hemisphere’s key climate modes of variability. Our analysis shows the historical observations are sensitive to the influence of large-scale dynamical drivers of Australian climate, as well as the relationship between southwestern and southeastern Australia. Finally, we demonstrate the ability of the dataset to resolve daily weather extremes by examining three severe storms that occurred in the nineteenth century associated with westerly storm tracks that influence southern Australia. The historical dataset introduced here provides a foundation for investigating pre-industrial weather and climate variability in southern Australia, extending the potential for attribution studies of anthropogenically-influenced weather and climate extremes.

“Plenty of business going on”

Australian Aboriginal author Alexis Wright contends that place is not separate and isolated unto itself but is instead part of a whole environment. While Carpentaria Country is a place of both end and beginning, then, where character and reader can find hope in the underlying bond between story, person, and place, it can also be explored as part of the national, extended literary place. Structurally bracketed by cyclones, Carpentaria is a story about hope in a land of the imagination in which a prophet emerges from a cyclone to warn of a town’s hypocrisy and to offer a chance for cultures to come together. When he is rejected, scapegoated, exiled, and murdered, a second cyclone catastrophically destroys the town, presenting in the true sense of apocalypse an opportunity for change and renewal of people and place. With this use of the apocalyptic cyclone trope, Wright’s novel situates within a national literary context: the sub-genre of Australian climate literature in which the apocalyptic cyclone as a trope of destruction, epiphany, and renewal plays a major role in relationships between Australian society, place, and community. As one of a group of Australian literary works within the context of that sub-genre, Carpentaria can be seen not only as a powerfully individual work of literature but also as one in which the spiritual as well as the physical experience of the Australian literary cyclone can bring together the conscious with the unconscious in the landscape of the mind as we seek to understand through story our extended relationships with place.

Controversies in the management of proximal deep vein thrombosis.

Controversies in the management of proximal deep vein thrombosis.

A survey on the use of rugs in Australian horses.

The practice of horse rugging has important implications for horse welfare and performance, but in Australia, rugging practices have not been properly documented. The objective of this study was to obtain an understanding of Australian horse rugging practices. An online survey reviewed the management of 2659 Australian horses over 12 months. Of the reported horses a total of 84.8% were rugged, although most owners (69.5%) indicated that they were unsure whether horses needed to be rugged at all. Rugging was felt by 59.8% of owners to be a requirement for horses in competition. Riding and competition were significantly associated with the use of rugs. Nearly all respondents (89.0%) felt that 'over-rugging' was a concern. However, 4.8% of owners would use up to 4 rugs at any one time on their horse and 21.4% of horses were still rugged in temperatures above 20°C in Australia. Many Australian horse owners (42.8%) also believe that horses feel cold if they are not rugged. Anthropomorphism when it comes to rugging horses cannot be justified as the horse has a much wider thermoneutral zone (TNZ) than humans. Australian climate, owner opinions, equestrian discipline and whether a horse is used for riding influence Australian horse rugging practices. However, current practices are based on limited available research and are not necessarily to the benefit of the horse. The major limitation was that the survey likely attracted respondents who are interested in the topic creating a self-selection bias.

Examining Potential Mechanisms of an Online Universal Prevention for Adolescent Alcohol Use: a Causal Mediation Analysis

Several universal school-based prevention programs, notably the Australian Climate Schools program, have proven efficacious at reducing and maintaining a lower level of harmful alcohol consumption relative to a control condition. Yet, there are limited studies investigating the potential mechanisms that account for the reduction in harmful alcohol consumption. The current study utilised modern causal mediation analysis to investigate whether several harm minimisation and social influence mediators could jointly account for the intervention effect observed in a large school-based sample. Four mediators representing knowledge, attitudes, normative perceptions, and self-efficacy to resist peer pressure were entered into a multiple casual mediation model using the potential outcomes framework. The results did not provide evidence for a joint multiple mediation model consisting of the hypothesised harm minimisation and social influence mediators. Additional research is required to further investigate the potential mechanisms underlying universal school-based prevention programs including social connectedness and cultural/environmental factors.

Introducing extended natural ventilation index for buildings under the present and future changing climates

Natural Ventilation (NV) in buildings has a significant potential to reduce building energy use, provide thermal comfort and improve indoor air quality. NV potential is highly dependent on climatic conditions and may change over time due to global warming. To ensure a sustained and efficient NV design, it is necessary to identify the maximum potential of NV in a given climate and its sensitivity to climate change. Accordingly, this research aims to i) quantify the Climatic Potential of Natural Ventilation (CPNV) under present climate conditions and explore how this potential may change over time in the future in different Australian climate zones, ii) propose a new index named the Climatic Potential of Extended Natural Ventilation (CPENV) which identifies to what extent NV can be exploited if elevated airspeed requirements are met, and iii) evaluate the sensitivity of both CPNV and CPENV indices to global warming. Results showed that CPNV could be extended up to 18% with a required airspeed. The results also highlighted that the Total Climatic Potential of Natural Ventilation (TCPNV) could increase up to 27% or decrease up to 14.3% based on the present climate zone in the future.

Storylines of Geoengineering in the Australian Media: An Analysis of Online Coverage 2006–2018

ABSTRACT In the light of inadequate global emissions mitigation, geoengineering – solar radiation management and carbon dioxide removal – is increasingly being positioned and problematized by some researchers, policymakers, and advocates as a partial solution for avoiding catastrophic levels of warming. However, there are concerns that geoengineering may serve as a rhetorical tactic for delaying emissions reduction. As the news media field is an important space in which storylines surrounding geoengineering are created and circulated, the manner in which media actors discuss these topics is an important factor that can legitimate some policy pathways and close off others. In this paper, we analyze patterns in news media coverage of geoengineering in Australia to identify four dominant storylines: “a symptom of systems failure”, “silver buckshot”, “the Faustian bargain”, and “time for plan B”. We consider the implication of these storylines for the role that geoengineering may play in the Australian climate policy regime. We identify a risk geoengineering may be positioned as a rhetorical tactic for delaying emissions reduction. However, we note that the storylines in the public sphere provide a basis for public debate that engages critically with geoengineering, engaging with risks and differentiating solar radiation management from carbon dioxide removal.

What Can Machine Learning Teach Us about Australian Climate Risk Disclosures?

There seems to be no agreed taxonomy for climate-related risks. The information in firms’ climate risk disclosures represents a new resource for identifying the priorities and strategies of Australian companies’ management of climate risk. This research surveys 839 companies listed on the Australian Stock Exchange for the presence of climate risk disclosures, identifying 201 disclosures on climate risk. The types of climate risks and the risk management strategies were extracted and evaluated using machine learning. The analysis revealed that Australian firms are focused on acute physical climate risks, followed by market and regulatory risks. The predominant management strategy for these risks was to use a risk reduction approach, rather than avoiding or transferring risk. The analysis showed that key Australian industry sectors, such as materials, banking, insurance, and energy are focusing on different mixtures of risk types, but they are all primarily managing risks through risk-reduction strategies. An underlying driver of climate risk disclosure was composed of the financial implications of climate risk, particularly with respect to acute physical risks. The research showed that emission reductions represent a primary consideration for Australian firms in their disclosures identifying how they are responding to climate risk. Further research using machine learning to evaluate climate risk disclosure should focus on analysing entire climate risk reports for key topics and trends over time.

The promise and peril of Australian climate leadership under Albanese

After nearly a decade of policy inaction by the Abbott/Turnbull/Morrison Coalition governments, the election of Anthony Albanese’s Labor government has ushered in expectations of a sea-change in Australian climate policy, one that might allow the country to finally emerge as a global leader on the issue. Yet while years of inaction have left some relatively easy victories for the new government to rack up, the change of leadership and rhetoric obscures some key continuities in the Albanese government’s approach that need to be foregrounded and critiqued by domestic and international audiences alike. In this brief commentary, we consider what the new Labor government might mean for Australian climate action over the coming years. We focus, in particular, on the role that fossil fuel exports will continue to play in overwhelming any emissions cuts achieved domestically, and underscore the need for a much broader and more ambitious national climate strategy designed to wean the country off its reliance on coal and gas revenues.

Emerging trends in Australian climate change litigation: Bringing the heat

This article examines trends in Australian climate change litigation and emerging possibilities for future cases. It considers three categories of case: public sector government accountability, corporations in the private sector, and human rights. This analysis situates cases within the Paris Agreement categories of action (adaptation, mitigation, and loss and damage) and shows how the Paris Agreement categories and targets are developing into legal standards through case law.

Tipping Points and Changes in Australian Climate and Extremes

Systematic changes, since the beginning of the 20th century, in average and extreme Australian rainfall and temperatures indicate that Southern Australian climate has undergone regime transitions into a drier and warmer state. South-west Western Australia (SWWA) experienced the most dramatic drying trend with average streamflow into Perth dams, in the last decade, just 20% of that before the 1960s and extreme, decile 10, rainfall reduced to near zero. In south-eastern Australia (SEA) systematic decreases in average and extreme cool season rainfall became evident in the late 1990s with a halving of the area experiencing average decile 10 rainfall in the early 21st century compared with that for the 20th century. The shift in annual surface temperatures over SWWA and SEA, and indeed for Australia as a whole, has occurred primarily over the last 20 years with the percentage area experiencing extreme maximum temperatures in decile 10 increasing to an average of more than 45% since the start of the 21st century compared with less than 3% for the 20th century mean. Average maximum temperatures have also increased by circa 1 °C for SWWA and SEA over the last 20 years. The climate changes in rainfall an d temperatures are associated with atmospheric circulation shifts.

The Impact of Interacting Climate Modes on East Australian Precipitation Moisture Sources

Abstract Modes of climate variability can drive significant changes to regional climate affecting extremes such as droughts, floods, and bushfires. The need to forecast these extremes and expected future increases in their intensity and frequency motivates a need to better understand the physical processes that connect climate modes to regional precipitation. Focusing on east Australia, where precipitation is driven by multiple interacting climate modes, this study provides a new perspective into the links between large-scale modes of climate variability and precipitation. Using a Lagrangian back-trajectory approach, we examine how El Niño–Southern Oscillation (ENSO) modifies the supply of evaporative moisture for precipitation, and how this is modulated by the Indian Ocean dipole (IOD) and southern annular mode (SAM). We demonstrate that La Niña modifies large-scale moisture transport together with local thermodynamic changes to facilitate local precipitation generation, whereas below-average precipitation during El Niño stems predominantly from increased regional subsidence. These dynamic–thermodynamic processes were often more pronounced during co-occurring La Niña/negative IOD and El Niño/positive IOD periods. As the SAM is less strongly correlated with ENSO, the impact of co-occurring ENSO and SAM largely depended on the state of ENSO. La Niña–related processes were exacerbated when combined with +SAM and dampened when combined with −SAM, and vice versa during El Niño. This new perspective on how interacting climate modes physically influence regional precipitation can help elucidate how model biases affect the simulation of Australian climate, facilitating model improvement and understanding of regional impacts from long-term changes in these modes. Significance Statement How climate modes modulate the oceanic and terrestrial sources of moisture for rainfall in east Australia is investigated. East Australia is wetter during La Niña because more moisture is transported into the region and is more easily turned into rainfall when it arrives, whereas drier conditions during El Niño are because local conditions inhibit the conversion of moisture into rainfall. Distant atmospheric changes over the Indian and Southern Oceans can intensify these changes. Our results can be used to better understand and predict the regional impact of long-term changes in these modes of climate variability, which are potentially altered under climate change.