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This paper examines the potential role for fuel substitution in electricity production in reducing carbon dioxide emissions over a ten-year time horizon. This is achieved by adding fuel substitution to output changes resulting from demand responses arising from a tax on carbon dioxide emissions. A time profile of adjustments is developed. The tax required for Australia to meet a 20 per cent reduction in emissions from 1993 levels is calculated and effects on inequality and social welfare are examined. The paper also examines the potential effect of a subsidy towards the use of low- emission fuels, financed from the carbon tax. A subsidy produces an improvement in emissions abatement and a lower tax required to reach the emissions target. [ABSTRACT FROM AUTHOR]

Abstract: Climate change has been described as the biggest global health threat of the 21st century. The atmospheric concentrations of greenhouse gases, such as carbon dioxide, methane and nitrous oxide, have increased significantly since the start of the Industrial Era around 1750, with much of this increase occurring over just the last 50 years or so. This is resulting in warming of the climate system as well as changes in precipitation and weather and climate extremes. These changes in climate are having wide‐ranging impacts on the Earth’s physical, biological and human systems, including human health. It is these impacts of climate change on human health that are the focus of this paper, particularly the impacts on allergens and allergic diseases. Such impacts are particularly significant in many countries where the prevalence of such diseases is high and/or increasing. There is now compelling evidence that rising air temperatures and carbon dioxide concentrations are, in some plant species, resulting in increased pollen production and allergenicity and advancement and lengthening of the pollen season. Changes in extreme events, such as thunderstorms and tropical cyclones, will also have impacts on allergic diseases, with, for example, the flooding associated with tropical cyclones leading to proliferation of mould growth in damp homes. The article also considers a range of responses to these health threats, including greenhouse gas mitigation, and adaptation strategies, such as enhanced environmental monitoring and health surveillance and adequate planning for the future medical workforce. [ABSTRACT FROM AUTHOR]

The emission of greenhouse gases, particularly carbon dioxide, and the consequent potential for climate change are the focus of increasing international concern. Temporary land-use change and forestry projects (LUCF) can be implemented to offset permanent emissions of carbon dioxide from the energy sector. Several approaches to accounting for carbon sequestration in LUCF projects have been proposed. In the present paper, the economic implications of adopting four of these approaches are evaluated in a normative context. The analysis is based on simulation of Australian farm–forestry systems. Results are interpreted from the standpoint of both investors and landholders. The role of baselines and transaction costs are discussed. [ABSTRACT FROM AUTHOR]

Household CO2 emissions are a significant contributor to global greenhouse gas emissions and consequently climate warming. Despite this, there has been little consideration of how household CO2 emissions may be affected by changes in climate. The aim of the present study has been to investigate the way climate, as well as socio-demographic characteristics, may affect household CO2 emissions produced from energy use. A national online survey was conducted to determine current household CO2 emissions in Australia as well as capture the ownership and use of household appliances and installations. Electricity and gas-based emissions as well as the ownership of a variety of household appliances and installations were found to be strongly associated with temperature. Electricity and gas emissions were found to decrease as annual average temperatures increase. However, as temperatures continue to rise under climate change this pattern may be reversed owing to increased reliance on air conditioners. One option for preventing this from occurring is to encourage houses to adopt more solar-passive installations. Although this may be expensive, households with higher emissions tend to have higher incomes, indicating that they may have the capacity to pay for such installations. [ABSTRACT FROM AUTHOR]

High global uncertainties remain in water‐air CO2, CH4, and N2O fluxes from estuaries due to spatial and temporal variability and the poor predictability of the gas transfer velocity (k600). This is the first study that directly compares k600 of CO2, CH4, and N2O in an estuary with the aim to evaluate the accuracy of using a uniform k600 value for estimating water‐air fluxes. We calculated 155 k600 values from CO2, CH4, and N2O fluxes over spatial (across, along) and temporal (tidal cycle) surveys in the subtropical Maroochy estuary using the floating chamber method. Combined k600 values showed a large range over the entire estuary (0.1–198.6 cm h−1) with slightly lower k600 in the lower compared to the upper estuary. Overall, temporal variability was greater than spatial variability of k600. We found the highest variability of k600 between gas species in the lower estuary, whereas the variability was less distinct in the upper estuary. In the Maroochy estuary, k600CO2 (mean 26.4 ± 37.3 cm h−1) was mostly higher than k600CH4 (mean 10.9 ± 10.6 cm h−1) and k600N2O (mean 9.9 ± 12.3 cm h−1), likely due to chemical and enzymatic enhancements and/or microbial activity in the surface microlayer. We demonstrate that empirical k600 models intended for CO2 may not accurately predict CH4 and N2O fluxes in estuaries. Our tested k600 models predicted the measured fluxes within an uncertainty range of 5%–40% (over or underestimation), but precise flux estimates should be based on in situk600 of all three gases. Plain Language Summary: Greenhouse gas emissions from estuaries are an important component of the coastal ocean carbon cycle. However, carbon dioxide, methane, and nitrous oxide fluxes from estuaries remain uncertain at the global scale, partially because of the gas transfer velocity, a relevant parameter of the flux computation. This study is the first study, to our knowledge, that directly compares gas transfer velocities of the three greenhouse gases with each other and over spatial and temporal gradients in a subtropical estuary in Australia. We find that gas transfer velocities were gas‐specific and differed in upper, mid, and lower estuary regions. The non‐uniformity of the gas transfer velocity in heterogeneous estuaries is likely due to different chemical, physical and biological processes that drive gas transfer of the three gases at the water‐air interface. This is important to consider when estimating estuary fluxes because models for one specific gas may not accurately predict the gas transfer of the other two greenhouse gases. Key Points: k600 of CO2, CH4, and N2O were non‐uniform over spatial and temporal estuary gradients and k600CO2 mostly greater than k600CH4 and k600N2OVariability of k600 between the gas species was greater at the estuary mouth compared to the mid and upper estuary sectionsEmpirical k600CO2 models may not accurately predict CH4 and N2O fluxes because they do not account for gas‐specific non‐diffusive processes [ABSTRACT FROM AUTHOR]

Low carbon readiness (LCR) is an aspect of environmental identity, an individual citizen's willingness to reduce carbon emissions and transition to low carbon lifestyle as a personalstriving. Nevertheless, individuals' personal strivings are strongly influenced by the social context in which they are situated. We propose the social context of environmental identity model, which postulates that social contexts for LCR have a nested structure. The micro‐level Home is linked with other households through social networks at the meso‐level Community, which are further embedded in a macro‐level Society. These contexts are likely to influence LCR through different mechanisms. Home can exert direct influences by monitoring and reminding each other of the need to engage in low carbon behaviours. Community affects individuals' readiness by providing social capital. The macro‐level Society exerts social influence through societal norms not only its current descriptive norm but also through its dynamic norms about the changing trends into the future. We have tested and found support for these propositions in three national cross‐sectional data sets from Australia. Our discussions will centre around a need to investigate social and cultural processes involved in climate change mitigation, and to link these insights to public policies. [ABSTRACT FROM AUTHOR]

Flue gas desulfurisation is a prerequisite for successful CO2 capture in coal‐fired power stations utilising aqueous amine absorbents. For nations like Australia, where there is nonexistence of mandatory flue gas desulfurisation, this increases the cost for power plants retrofitting CO2 capture. The CSIRO's CS‐Cap process, a potentially low cost method for combined CO2 and SO2 capture, provides an alternate sulfur management solution to such plants. The CS‐Cap process, however, results in high sulfur‐loaded amines that require continuous regeneration to retain cost benefits. Reactive crystallisation by KOH addition is shown to be successful in removing the bulk of the sulfate from aqueous amines without any additional heating or cooling requirements. Increasing initial sulfate loading by amine recycling initially improves sulfate removal efficiency, up to the postsaturation level where the systems ionic strength determines further sulfate solubility. Oxidative amine degradation had no significant effect on the precipitation efficiency or purity of K2SO4 crystals apart from their slight discoloration. The behaviour of the residual potassium in these regenerated aqueous amines needs further investigation as it could lead to unwanted precipitation inside the absorber column and other parts of the process. [ABSTRACT FROM AUTHOR]

Coral reefs cover approximately 0.10 to 0.25% of the marine environment and yet are home to around 25% of marine species and support the livelihoods of more than 500 million people. They face a wide range of threats, with the impact of global warming gaining most attention due to its frequently claimed causal link to coral bleaching. Here we review a decade of research into the micrometeorology of Heron Reef, a lagoonal platform coral reef in the southern Great Barrier Reef, Australia. Using novel pontoon‐mounted eddy covariance systems, we show that often >80% of net radiation is partitioned into heating the water overlying the reef, the reef benthos, and substrate. Significant spatial variability in energy and trace gas exchanges occurs over the reef in response to different geomorphic and hydrodynamic conditions. Synoptic weather patterns that bring light winds, clear skies, and high humidity, result in reef scale meteorology that appears to have a greater influence on coral bleaching events than the background oceanic warming trend. The reef develops its own convective internal boundary layer, with potential to influence cloud development and therefore the surface energy balance. Knowledge of such local effects is lacking, so it is recommended that future research is needed into reef scale processes and how they interact with larger‐scale forcing. Key Points: A decade of research on the meteorology of Heron Reef in the Great Barrier Reef, Australia, is reviewedEnergy flux and trace gas exchange with the atmosphere over Heron Reef under a range of conditions including coral bleaching are summarizedSuggestions are made for future research to advance understanding of coral reef – atmosphere interactions [ABSTRACT FROM AUTHOR]

Ocean warming 'hotspots' are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2-driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas. [ABSTRACT FROM AUTHOR]

Background Blood gas analysis is an important part of the assessment of ventilatory function in patients with respiratory distress. Traditionally, analysis of arterial blood has been used, but recently, there has been a move towards venous blood gas analysis for selected conditions. Arteriovenous agreement for pH and pCO2 in adult patients undergoing non-invasive ventilation ( NIV) has not been explored to date. The aim of this study was to address this question. Methods This was a prospective study of adult patients undergoing NIV for acute respiratory compromise in an ED. When arterial blood gas analysis was required for clinical purposes, staff also drew a venous sample as close to simultaneously as possible. Data collected included demographics, clinical diagnosis and results of blood gas analyses. Primary outcome of interest was arteriovenous agreement for pH and pCO2. Bland- Altman bias plot analysis was used. Results Eighty-nine sample pairs in 53 patients were studied. Median age was 74, and 64% of patients were male. The principal diagnoses were chronic obstructive pulmonary disease (43%) and acute pulmonary oedema (40%). Mean difference for pH (a-v) was 0.04 pH units (95% limits of agreement −0.02, 0.11). Mean difference for pCO2 (a-v) was −8.02 mmHg (95% limits of agreement −22.63, 6.58) Conclusion For adult patients undergoing NIV in an ED, arteriovenous agreement for pH was close with narrow limits of agreement making venous pH clinically interchangeable with arterial pH. Agreement for pCO2 was poor with unacceptably wide limits of agreement. [ABSTRACT FROM AUTHOR]

Electricity generators accept that emissions trading is fundamental to meeting CO2 reduction targets. But unless a percentage of permits are allocated, existing generators will face non-trivial wealth transfers. Seldom contemplated in academic works are the adverse economic consequences of an all-auction approach to emissions trading. Using Victoria to illustrate, we find that once CO2 prices exceed $17.50/t, the marginal coal generator facing large wealth transfers will withhold generating capacity to raise prices and recoup stranded investments, thus becoming a ‘wounded bull’ in the market place. This has material welfare implications with modelling results indicate an intermediate-run 300 per cent increase in wholesale power prices. [ABSTRACT FROM AUTHOR]

The FeCycle experiment provided an SF6 labeled mesoscale patch of high-nitrate low-chlorophyll (HNLC) water in austral summer 2003. These labeled waters enabled a comparison of the inventory of particulate iron (PFe) in the 45-m-deep surface mixed layer with the concurrent downward export flux of PFe at depths of 80 and 120 m. The partitioning of PFe between four size fractions (0.2-2, 2-5, 5-20, and >20 μm) was assessed, and PFe was mainly found in the >20-μm size fraction throughout FeCycle. Estimates of the relative contribution of the biogenic and lithogenic components to PFe were based on an A1:Fe molar ratio (0.18) derived following analysis of dust/soil from the nearest source of aerosol Fe: the semi-arid regions of Australia. The lithogenic component dominated each of the four PFe size fractions, with medians ranging from 68 to 97% of PFe during the 10-day experiment. The Fe:C ratios for mixed-layer particles were ∼40 μmol/mol. PFe export was ∼300 nmol m-2 d-1 at 80 m depth representing a daily loss of ∼1% from the mixed-layer PFe inventory. There were pronounced increases in the Fe:C particulate ratios with depth, with a five-fold increase from the surface mixed layer to 80 m depth, consistent with scavenging of the remineralized Fe by sinking particles and concurrent solubilization and loss of particulate organic carbon. Significantly, the lithogenic fraction of the sinking PFe intercepted at both 80 m and 120 m was >40%; that is, there was an approximately twofold decrease in the proportion of lithogenic iron exported relative to that in the mixed-layer lithogenic iron inventory. This indicates that the transformation of lithogenic to biogenic PFe takes place in the mixed layer, prior to particles settling to depth. Moreover, the magnitude of lithogenic Fe supply from dust deposition into the waters southeast of New Zealand is comparable to that of the export of PFe from the mixed layer, suggesting that a large proportion of the deposited dust eventually exits the surface mixed layer as biogenic PFe in this HNLC region. [ABSTRACT FROM AUTHOR]

Summary • Will changes in nutritive values and N-relations offset initial gains in forage productivity under potential climate change observed for grass–legume pastures of south-eastern Australia? • Herbage nutritive value and symbiotic nitrogen fixation were investigated for pure and mixed swards of subterranean clover (Trifolium subterraneum ) and phalaris (Phalaris aquatica ) in field tunnels at ambient and 690 µmol mol-1 CO2 concentrations and at ambient and warmed (+3.4°C) air temperatures. • Elevated CO2 increased the nonstructural carbohydrate content of herbage whereas warming tended to decrease it. These effects were mainly on soluble carbohydrates in phalaris and starch in clover herbage. The N concentration of both species was decreased by elevated CO2 but unaffected by warming. The proportion of clover-N derived from N2 fixation was increased by 12% under elevated CO2 but decreased by 6% under warming. • Concurrent warming and high-CO2 conditions are expected to lead to improved herbage nutritive value for ruminants due to increased nonstructural soluble carbohydrate content. Longer term effects on nutritive value and N-dynamics via species persistence and competition require further study. [ABSTRACT FROM AUTHOR]