• Energy Research
• 2016-2025close
• 13. Climate action close
• 3. Good health close
• University of Queensland close

Vegetated coastal ecosystems, in particular mangroves, tidal marshes and seagrasses are highly efficient at sequestering and storing carbon, making them valuable assets for climate change mitigation and adaptation. The state of Queensland, in northeastern Australia, contains almost half of the total area of these blue carbon ecosystems in the country, yet there are few detailed regional or state-wide assessments of their total sedimentary organic carbon (SOC) stocks. We compiled existing SOC data and used boosted regression tree models to evaluate the influence of environmental variables in explaining the variability in SOC stocks, and to produce spatially explicit blue carbon estimates. The final models explained 75 % (for mangroves and tidal marshes) and 65 % (for seagrasses) of the variability in SOC stocks. Total SOC stocks in the state of Queensland were estimated at 569 ± 98 Tg C (173 ± 32 Tg C, 232 ± 50 Tg C, and 164 ± 16 Tg C from mangroves, tidal marshes and seagrasses, respectively). Regional predictions for each of Queensland's eleven Natural Resource Management regions revealed that 60 % of the state's SOC stocks occurred within three regions (Cape York, Torres Strait and Southern Gulf Natural Resource Management regions) due to a combination of high values of SOC stocks and large areas of coastal wetlands. Protected areas in Queensland play an important role in conserving SOC assets in Queensland's coastal wetlands. For example, ~19 Tg C within terrestrial protected areas, ~27 Tg C within marine protected areas and ~ 40 Tg C within areas of matters of State Environmental Significance. Using multi-decadal (1987-2020) mapped distributions of mangroves in Queensland; we found that mangrove area increased by approximately 30,000 ha from 1987 to 2020, which led to temporal fluctuations in mangrove plant and SOC stocks. We estimated that plant stocks decreased from ~45 Tg C in 1987 to ~34.2 Tg C in 2020, while SOC stocks remained relatively constant from ~107.9 Tg C in 1987 to 108.0 Tg C in 2020. Considering the level of current protection, emissions from mangrove deforestation are potentially very low; therefore, representing minor opportunities for mangrove blue carbon projects in the region. Our study provides much needed information on current trends in carbon stocks and their conservation in Queensland's coastal wetlands, while also contributing to guide future management actions, including blue carbon restoration projects.

AbstractClimate change is having a significant impact on ecosystem services and is likely to become increasingly important as this phenomenon intensifies. Future impacts can be difficult to assess as they often involve long timescales, dynamic systems with high uncertainties, and are typically confounded by other drivers of change. Despite a growing literature on climate change impacts on ecosystem services, no quantitative syntheses exist. Hence, we lack an overarching understanding of the impacts of climate change, how they are being assessed, and the extent to which other drivers, uncertainties, and decision making are incorporated. To address this, we systematically reviewed the peer‐reviewed literature that assesses climate change impacts on ecosystem services at subglobal scales. We found that the impact of climate change on most types of services was predominantly negative (59% negative, 24% mixed, 4% neutral, 13% positive), but varied across services, drivers, and assessment methods. Although uncertainty was usually incorporated, there were substantial gaps in the sources of uncertainty included, along with the methods used to incorporate them. We found that relatively few studies integrated decision making, and even fewer studies aimed to identify solutions that were robust to uncertainty. For management or policy to ensure the delivery of ecosystem services, integrated approaches that incorporate multiple drivers of change and account for multiple sources of uncertainty are needed. This is undoubtedly a challenging task, but ignoring these complexities can result in misleading assessments of the impacts of climate change, suboptimal management outcomes, and the inefficient allocation of resources for climate adaptation.

Few studies on population-specific health effects of extreme temperature on cardiovascular diseases (CVDs) deaths have been conducted in the subtropical and tropical climates of China. We examined the association between extreme temperature and CVD across four cities in China. We performed a two-stage analysis; we generated city-specific estimates using a distributed lag non-linear model (DLNM) and estimated the overall effects by conducting a meta-analysis. Heat thresholds of 29 °C, 29 °C, 29 °C, and 30 °C and cold thresholds of 6 °C, 10 °C, 14 °C, and 15 °C were observed in Hefei, Changsha, Nanning, and Haikou, respectively. The lag periods for heat-related CVD mortality were observed only for 0–2 days, while those of cold-related CVD mortality were observed for 10–15 days. The meta-analysis showed that a 1 °C increase above the city-specific heat threshold was associated with average overall CVD mortality increases of 4.6% (3.0%–6.2%), 6.4% (3.4%–9.4%), and 0.2% (−4.8%–5.2%) for all ages, ≥65 years, and <65 years over a lag period of 0–2 days, respectively. Similarly, a 1 °C decrease below the city-specific cold threshold was associated with average overall CVD mortality increases of 4.2% (3.0%–5.4%), 4.9% (3.5%–6.3%), and 3.1% (1.7%–4.5%), for all ages, ≥65 years, and <65 years over a lag period of 0–15 days, respectively. This work will help to take appropriate measures to reduce temperature-mortality risk in different populations in the subtropical and tropical climates of China.

ABSTRACTIn 2012, a total of 13.1 million tonnes of carbon dioxide were emitted by 14 airlines while transporting 72 per cent of international passengers into and out of Australia in 2012. With passenger and cargo traffic growing at between five to six per cent annually from 2013 to 2033, acquiring more fuel efficient aircraft to both renew the existing fleet and to service growth has the greatest potential in reducing emissions over the next 20 years. Our analysis shows that implementing carbon dioxide emissions abatement options such as installing light weight seats, iPad electronic flight bags, winglets, washing aircraft engines and reducing the number of engines used during taxiing, all offer net financial savings when considered over 20 years. Acquiring new fuel efficient aircraft has the biggest impact on emissions reduction. Low interest loans and longer loan repayment periods may incentivise airlines to acquire more fuel efficient aircraft to service traffic growth but other complimentary incentive...

Abstract A key challenge for heavy industry in emerging economies is how to meet international greenhouse gas (GHG) emission standards since they are often based on the conditions and capacities of manufacturing in advanced countries. Firms in developing nations are typically cost-driven and reliant on older, less efficient technology: very few have achieved the relevant targets. Cement making underscores the point: no study to date has specifically quantified, in technical and financial terms, the gap between existing firm performance and global GHG emission standards. We examine Indonesia's largest cement manufacturing facility to investigate what needs to be done to overcome the discrepancy. The article starts by reviewing key contextual issues such as the facility's location, scale, organisational configuration, available materials, energy use, and technological capacities. The plant's direct emission intensity is 0.69 t CO2e/t cement, higher than the global target for 2030 (0.55 t CO2e/t). Analysis reveals six potential emissions reduction activities: (1) utilizing fly ash as a clinker substitute; (2) employing limestone as a clinker substitute; (3) using biomass from rice husks as an alternative fuel; (4) adding pre-heating stages in kilns; (5) waste heat recovery for power generation; and (6) using refused-derived fuel from municipal solid waste as an alternative fuel. These measures, if adopted in full, could reduce GHGs at the facility by up to 33%, or a total of 34,145,190 t CO2e over a 10-year timeframe (2020–2030). This abatement action would leave the facility's direct emissions intensity to 0.48 t CO2e/t cement. In present values, assuming a 10% discount rate, they would result in savings of US$415 million for a US$94 million outlay. Despite the apparent technical and financial advantages, all measures together are unlikely to be adopted, since the plant studied is well advanced in its lifecycle and the parent company is experiencing financial constraints common to those in developing nations.

Coral reefs are vulnerable to the impacts of global climate change (e.g rising sea temperature) as well as to numerous local disturbances (e.g overfishing). In combination, these impacts are known to degrade coral reefs, compromising critical ecosystem functions and leading to the potential loss of biodiversity and associated ecosystem services. Management aims to minimise these negative effects but is challenged by substantial uncertainty about the relative contribution and interactions among the various types of stressors on coral reefs. One of the most widely applied management tools on coral reefs are Marine Protected Areas (MPAs). MPAs restrict certain or all types of human activities within their boundaries and are aimed at rebuilding degraded habitats, maintaining ecosystem functions, and protecting healthy reefs to ensure the continued provision of ecosystem services. However, using MPAs effectively requires an understanding of their optimal placement to ensure the conservation of biodiversity and ecological functions in support of local communities and stakeholders. My thesis addresses this topic by developing a novel marine spatial planning approach that integrates reef ecosystem services explicitly into the decision-making process.The first chapter of my thesis is a general introduction that provides an overview of current scientific knowledge about the vulnerability of coral reefs and how these ecosystems are likely to respond to various impacts from global and local stressors. Chapter 2 is focused on investigating the response of coral communities to global and local disturbances more explicitly by using an ecological model to examine the impacts of sea surface temperature, local thermal stress, cyclone, fishing pressure, nutrient enrichment and crown of thorns starfish (CoTS) outbreaks on reefs under alternative climate scenarios by examining applied to Indonesian coral reefs. We used three greenhouse gas emissions (Representative concentration pathway - RCP8.5, RCP4.5, and RCP2.6) for the scenarios of climate change. Reefs are likely to experience further declines in coral cover under all alternative scenarios of climate change and local thermal regimes, but with varied rates of decline in different geographic locations. Management benefits were greater under the more pessimistic greenhouse gas emission scenario RCP8.5 and management of two local stressors with complementary ecological targets (i.e., coral recruitment and adult mortality) provided greater benefits than utilizing tools with similar modes of action. For example, combining approaches that targeted CoTS and either fishing or nutrients, that affect adult mortality and recruitment (respectively), had far greater efficacy than targeting the duality of fishing and nutrients, which both influence recruitment only. The results provide new insight into the importance of applying management tools that address different ecological processes.In Chapter 3, I establish a generally applicable MPA design approach to reconcile multiple reef ecosystem services under explicit consideration of local community needs. Using Selayar Island, South Sulawesi (Indonesia) as a case study, I found that the design of MPAs to address all three ecosystem services – biodiversity, fisheries productivity, and coastal protection – proved challenging. Relatively few reefs exhibit high values of all three services and optimization software is needed to seek network locations that achieve reasonable trade-offs between services. Local fishers valued fisheries benefits over biodiversity and coastal protection. Finding MPA networks that deliver fishers’ preferences was particularly difficult if attempting to include the highest levels of fisheries benefit. Compromising on the magnitude of fishery benefits provided much greater flexibility in the choice of MPA networks that delivered moderately high benefits across all services. Moreover, it becomes more challenging to find good solutions as the target level of MPA coverage increases from 10% to 30%, implying that fewer good solutions occur.In Chapter 4, I examine the extent to which governance factors and management processes, such as involvement of the local community in conservation planning and prior experience with MPAs, influence the perceived benefits of MPAs for fisheries. I incorporate governance factors and preferred MPA distribution based on interviews of local fisher communities. The results reveal that the better engagement of the community into the MPA planning process and governance of MPAs lead to a more positive perception of MPA benefits by fishers. Yet fishers’ perceptions of MPAs were more nuanced. Generally, the perceptions were less positive (1) in fishers that fish more frequently, and (2) fishers operating larger boats that include pelagic fishing (cf. fishers using small-scale artisanal methods). It is hypothesized that pelagic fishers are less invested in the benefits of MPAs and that fishers operating more frequently might be less likely to notice modest changes in productivity should it occur.I also asked whether fishers with a more positive perception of MPA benefits would be more likely to locate future MPAs closer to their fishing grounds. However, this simple hypothesis was not supported. Fishers in Selayar recommend a minimum average distance of ~5 km of MPAs from fishing grounds while people involved in MPA planning tended to suggest distances about 8 km farther from fishing grounds. The absence of a simple relationship between fisher perceptions and the separation of MPA-fishing grounds implies that other – unmeasured – factors are responsible. In general, our findings emphasize the importance of incorporating governance processes and social factors into MPA designation.In Chapter 5, I review my conclusions and consider their broader implications and needs for further work. Prioritising multiple reefs for multiple ecosystem services is challenging and therefore the use of optimisation software is necessary to find suites of MPAs that can meet such diverse objectives. A willingness to compromise on the absolute magnitude of fisheries benefits – the ecosystem service of the greatest value to the community – led to far greater flexibility in finding MPA solutions. Overall, tackling more complex sets of objectives is feasible but requires the use of standard optimisation software to select reasonable solutions. Yet management implementation, such as MPA design, requires good governance and an increasing reliance on sophisticated tools has the potential to undermine the transparency and inclusivity of the implementation process. Future studies will need to consider the communication of tools usage as well as the development of frameworks to apply the tools effectively.

Abstract In this paper, a multi-scale model is used to assess the multiple mineral precipitation potential in a full-scale anaerobic granular sludge system. Reactor behaviour is analysed under different operational conditions (addition/no addition of reject water from dewatering of lime-stabilized biomass) and periods of time (short/long term). Model predictions suggest that a higher contribution of reject water promotes the risk of intra-granule CaCO3 formation as a result of the increased quantity of calcium arriving with that stream combined with strong pH gradients within the biofilm. The distribution of these precipitates depends on: (i) reactor height; and (ii) granule size. The study also exposes the potential undesirable effects of the long-term addition of reject water (a decrease in energy recovery of 20% over a 100-day period), caused by loss in biomass activity (due to microbial displacement), and the reduced buffer capacity. This demonstrates how both short-term and long-term operational conditions may affect the formation of precipitates within anaerobic granules, and how it may influence methane production and consequently energy recovery.

PurposeThis paper aims to examine the complex issue of the social cost of carbon. The authors review the existing literature and the strengths and deficiencies of existing approaches. They introduce a simple methodology that estimates the amount of “legal looting” in the fossil fuel industry as an alternative approach to calculate an unpaid social cost of carbon. The “looting amount” can be defined as society’s failure to charge fossil fuel firms for the damage that their activities cause represents an implied subsidy.Design/methodology/approachThe methodology used in this paper combines decisions in the form of policymakers setting carbon taxes and rational investors investing in carbon emission markets.FindingsThe authors show that the unpaid social cost of carbon in the fossil fuel industry was US$12.7tn over 1995-2013, but may be as high as US$115.5tn.Originality/valueOver the same period, the sum of industry profits, emission trading scheme carbon permit and carbon tax revenue totalled US$7tn, indicating the industry would not be viable if it was made to pay for damages to society.