Greenhouse Gas Emissions Profile Research Articles

THE PERFORMANCE OF KUALA LUMPUR’S CARBON EMISSIONS IN THE CONTEXT OF URBAN PLANNING

Cities are responsible for 70% of greenhouse gas (GHG) emissions on a global scale, and cities play an important role in reducing GHG emissions. It is essential for Kuala Lumpur to consider reducing the city's GHG emissions. The city's GHG emission inventory can track and monitor the effectiveness of the climate action plans that has been implemented. The aim of this study is to identify the performance level of GHG emissions in Kuala Lumpur between 2010 and 2019. It is also to identify the performance of Kuala Lumpur's GHG emissions in 2019 in comparison to the global and Malaysian level. Data is calculated using the Global Protocol for Community-Scale Greenhouse Gas Emissions Inventory (GPC), which is recognised and utilised globally. Secondary data for the years 2010 and 2019 was analysed as well as the performance of the Kuala Lumpur GHG emission profile in 2019. With three (3) identified sources of emissions, Kuala Lumpur managed to reduce its GHG emission intensity from 2010 by 74.07% in 2019. The city's GHG emission was recorded at 15,675 ktCO2eq in 2019. The stationary energy sector contributes higher GHG emission than other sector, with 12,043 ktCO2eq (76.83%), followed by the transportation sector with 3,180 ktCO2eq (20.29%) and the waste sector with 452 ktCO2eq (2.88%). As of 2019, Kuala Lumpur's absolute carbon contribution to the global average is 0.03%, whereas Malaysia's absolute carbon contribution is 4.74%. Additionally, the city contributes just 0.07 kgCO2eq/RM (30.17%) to Malaysia's total GHG emission intensity.

Development of South Africa Macadamia Nuts and its Utilization for Biodiesel Production

Demands for energy are rising as the world's population expands. To meet these demands, fossil fuels have been overused, yet this over reliance on them has led to their depletion. The usage of fossil fuels has also significantly contributed to the release of greenhouse gases, which is a serious environmental concern. Sustainable energy is therefore environmentally friendly and financially sound. Petro-diesel can be replaced by biodiesel because it is biodegradable and less hazardous. Biofuel is any fuel produced from biomass, which can be either animal fats or waste, plant or algae material as a feedstock. Biomass benefits in producing fuels which helps to lessen the demand for petroleum fuel and products. Petroleum fuel and gas increase the greenhouse gas emissions profile of the transportation sector. The Republic of South Africa (RSA) is the 14th world's largest emitter of greenhouse gases. This is due to the emissions resulting from burning and heavy reliance on coal. Since biofuel can be produced domestically from natural sources like soybeans, rapeseed, macadamia nuts, coconuts, and even leftover cooking, it has the potential to serve as a remarkable substitute for the commonly used petroleum-derived diesel fuel. This study addresses the historical development of macadamia nuts with a focus on the South African Macadamia Nuts (SAMN) industry, its origin, and as a feedstock for biodiesel production. The generation and classification of biodiesel, physicochemical properties, biodiesel standards, and both American Society for Testing and Materials (ASTM), European Committee for Standardization (EN 14214), and South African biodiesel framework standards are discussed. Furthermore, the biodiesel blending requirements, techniques, and benefits were outlined. Finally, the biodiesel regulatory framework of SA and biodiesel framework as per the Biodiesel Task team (BTT) was examined.

Measurement of Long-Term CH4 Emissions and Emission Factors from Beef Feedlots in Australia

One of the major challenges for the Australian feedlot and meat sectors is to have accurate and robust long-term greenhouse gas (GHG) emissions data. Long-term measurements of methane (CH4) emissions (2015–2017) were made at two Australian beef feedlots having different climates, cattle types, and management practices. Emissions were measured using the inverse-dispersion model (IDM) micrometeorological technique, using CH4 concentrations measured at the feedlots with a closed-path Fourier transform infrared spectroscopic technique (CP-FTIR). The emissions data were used to evaluate methods used by the Department of Climate Change, Energy, the Environment and Water to estimate CH4 emissions from feedlots in Australian national inventory calculations. Expressed as a CH4 yield (emissions per unit dry matter intake, DMI), the two feedlots had emissions of 13.1 and 18.9 g CH4 kg−1 DMI. The lower-emitting feedlot had emissions that were 30% lower than the national inventory calculations based on feed intakes, while the second feedlot had emissions that were similar to the inventory calculations. The accurate quantification of emissions from feedlots, as demonstrated as part of this study, is important for validating the national accounting methods and therefore the sector’s GHG emissions profile.

Unexpected low CO2 emission from highly disturbed urban inland waters

Constituents and functionality of urban inland waters are significantly perturbed by municipal sewage inputs and tailwater discharge from wastewater treatment plants. However, large knowledge gaps persist in understanding greenhouse gas dynamics in urban inland waters due to a lack of in situ measurements. Herein, via a 3-year field campaign (2018–2020), we report river and lake CO2 emission and related aquatic factors regulating the emission in the municipality of Beijing. Mean pCO2 (546 ± 481 μatm) in the two urban lakes was lower than global non-tropical freshwater lakes and CO2 flux in 47% of the lake observations was negative. Though average pCO2 in urban rivers (3124 ± 3846 μatm) was among the higher range of global rivers (1300–4300 μatm), average CO2 flux was much lower than the global river average (99.7 ± 147.5 versus 358.4 mmol m−2 d−1). The high pCO2 cannot release to the atmosphere due to the low gas exchange rate in urban rivers (average k600 of 1.3 ± 1.3 m d−1), resulting in low CO2 flux in urban rivers. Additionally, eutrophication promotes photosynthetic uptake and aquatic organic substrate production, leading to no clear relationships observed between pCO2 and phytoplankton photosynthesis or dissolved organic carbon. In consistence with the findings, CO2 emission accounted for only 32% of the total greenhouse gas (GHG) emission equivalence (CO2, CH4 and N2O) in Beijing waters, in contrast to a major role of anthropogenic CO2 to anthropogenic GHG in the atmosphere in terms of radiative forcing (66%). These results pointed to unique GHG emission profiles and the need for a special account of urban inland waters in terms of aquatic GHG emissions.

Comparative analysis of the USA's Washington Ferries and road transport carbon emissions using the Trozzi and Vaccaro and Greatest Integer functions.

Countries' sectors are currently under great scrutiny for their response to the greenhouse gas (GHG) emission profile and the general effect of the sectoral activities on the environment. As in the agenda of all sectors, environmental concerns and investigations are of high importance in shipping and maritime transport. Amidst the rising forms of globalization, the need for sustainable transportation is constantly increasing. However, the machines that are the cornerstone of transportation largely depend on fossil fuels, thus resulting in environmental degradation. Notably, environmental-related degradation has continued to account for global warming, climate change, and ocean acidification. Shipping is considered the most environmentally friendly mode of transportation in terms of carbon dioxide (CO2) emissions per ton per mile of transported unit load when compared against road transportation. In this study, six ferry lines (FLs) of Washington State Ferries were calculated to compare ship-generated carbon dioxide (CO2) emissions with those from road transportation as if the carried vehicles had used the highway instead of transport by FL. While making these calculations, the Greatest Integer function (GIF) and Trozzi and Vaccaro function (TVF) were utilized. From the examined three scenarios, i.e., all passengers travel by car instead of ferry as scenario 1, all ferries carry both cars and passengers as scenario 2, and all car-free passengers travel by bus instead of ferry as scenario 3, the outlined results are as follows: (i) none of the cars were carried by the ferry, and car-free passengers preferred traveling by their own cars as observed in scenario 1; (ii) hypothetical scenarios (1 to 3) in which the road vehicles carried on FLs had instead used the highway, and the total potential CO2 emissions of these road vehicles were calculated as 2,638,858.138, 704,958.2998, and 1,394,148.577 tonnes per year, respectively. Policy-wise, this study revealed the management strategies for CO2 emissions reduction for two transport modes, shipping and road transportation, under current conditions.

Does the metric matter? Climate change impacts of light-duty vehicle electrification in the US

Vehicle electrification is one of the most promising climate change mitigation strategies for light-duty vehicles (LDVs). But vehicle electrification shifts the greenhouse gas (GHG) emission profiles of conventional LDVs with emissions moving upstream from vehicle use to electricity generation and vehicle production. Electric vehicle (EV) deployment needs to be examined with life cycle assessment (LCA), both at vehicle and fleet levels. Climate change assessments of EVs are usually conducted using global warming potential (GWP), a normalized metric that aggregates GHG emissions. GWP suffers from some limitations as it ignores the emission timing over the product life cycle. In this study, we examine climate change impacts of four vehicle technologies (conventional, hybrid, plug-in hybrid, and battery electric vehicles) in the US at vehicle and fleet levels using four climate change metrics (GWP, dynamic global warming impact, radiative forcing impact and global temperature change impact). One of our key findings is that while the choices of the metric, the analytical time period, and some other key parameters, such as methane leakage rate, may have substantial influences on the results, partial and full electrification remain effective solutions to reduce climate change impacts of the US LDVs. However, the transient effects that exist between GHG emissions, radiative forcing, and global temperature changes imply that climate change impact reductions of vehicle electrification take time to materialize and are overestimated with GWP. It is therefore critical to evaluate large-scale implications of climate change mitigation strategies with multiple metrics to fully capture and assess the expected benefits. We nonetheless found that GWP is a robust metric for climate change mitigation targets of vehicle electrification and remains a good choice for most analysis.

Modelling the production, profit, and greenhouse gas emissions of Irish sheep flocks divergent in genetic merit

CONTEXTSheep production industries face the challenge of increasing farm production and profit while reducing environmental impacts. OBJECTIVESGenetic selection using multi-trait breeding indices can be used to improve flock productivity, profitability, and greenhouse gas (GHG) emissions intensities (kg CO2-eq /kg of product), however validation of the improved performance of animals ranked higher on breeding indices at a flock level is required. METHODSPhenotypic data from 387,580 production records of animals born between 2018 and 2020 of known genetic merit in commercial flocks were inputted to an established bio-economic model. Two contrasting flocks were compared, a flock of ewes ranked High (top 20%) on the Irish replacement Index bred with rams ranked High on the replacement and terminal indices, and a flock of ewes ranked Low (bottom 20%) on the Irish replacement Index bred with rams ranked Low on the replacement and terminal indices. The two flocks were then simulated using life cycle assessment to estimate the GHG emissions profile for both systems. RESULTS AND CONCLUSIONFlock weaning rates were 1.70 and 1.53 lambs weaned per ewe presented for breeding for the High and Low genetic merit flocks, respectively. The flock of High genetic merit ewes sold 0.17 more lambs per ewe, equating to 3.29 kg more lamb carcass per ewe, than the flock of Low genetic merit ewes; lambs from the High genetic merit flock were also sold at an earlier age. The greater production of the High genetic merit flocks resulted in an additional €18/ewe net profit than the Low genetic merit flock. Although total flock GHG emissions were higher for the High genetic merit flock, GHG emissions intensities were lower at 21.7 and 23.3 kg CO2-eq /kg lamb carcass sold for the High and Low genetic merit flocks, respectively. The lower emissions intensity of the High genetic merit flock was due to the dilution effect of higher lamb production and lambs being drafted for slaughter ealier. SIGNIFICANCEThe results suggest Irish sheep producers can make substantial profit gains through selection according to the national breeding indices while also reducing their environmental impact, and farmers should consider genetic merit when purchasing their rams, particularly sires of replacement ewe lambs.

Climate policy impacts on building energy use, emissions, and health: New York City local law 97

Climate policies increasingly focus on the building sector to reduce its energy and emission footprint, since building energy use is a major source of greenhouse gas (GHG) and air pollution emissions. The most ambitious climate policy focusing on the building sector is New York City (NYC)'s local law 97 (LL97). LL97 requires all mid-size and large buildings (>25,000 ft2 (2,323 m2)) to reduce the GHG emissions associated with their energy use, 40% by 2030, and 80% by 2050. This study uses several models and regulatory datasets to build novel NYC building energy use and GHG emission profiles based on LL97 and to investigate the impacts of LL97 on energy, climate, and health. Results show that climate impacts of 2018 energy use in LL97-covered buildings is ∼$3.24 billion USD. The premature mortality due to exposure to 2017 NYC stationary fuel combustion emissions were 1.73–3.42K deaths ($19.9–39.2 billion USD). From this total premature mortality cases in stationary sectors (industry, electricity, and buildings), 0.838–1.87K deaths ($9.62–21.5 billion USD) were from buildings. To achieve emission reduction goals and enable beneficial building electrification, the grid should be decarbonized. Additionally, LL97's apparent exclusion of biomass is a key gap, with potentially adverse effects on health and broad implications for energy/climate policies. Biomass has an outsized adverse health impact; NYC biomass use alone caused 0.707–1.55K deaths ($8.12–17.8 billion USD) in 2017. Yet LL97 does not explicitly mention biomass, and may inadvertently incentivize the use of this fuel, for instance by enabling the use of renewable energy credits from biomass for compliance. This can lead to increased adverse health impacts from biomass combustion. Our findings demonstrate the necessity of including health in energy and climate policy design.

Can global value chain participation affect embodied carbon emission intensity?

With the deepening of the global division of labor, it is significant to analyze the impact of global value chain participation on embodied carbon emission intensity. It provides implications for countries to address climate issues and improve development quality. The present work uses a multi-region input-output table provided by World Input Output Database to calculate the global value chain participation and the embodied carbon emission intensity of 42 different countries, for the period between 2000 and 2014. In addition, we decompose the carbon emission intensity into the carbon emission intensity embodied in domestic demand and foreign exports demand, and the carbon emission intensity of foreign exports demand is further divided into three types of embodied carbon emission intensity. Then, we analyze how global value chain participation affects the embodied carbon emission intensity, and examine different impacts across different development countries and different types of embodied carbon emission intensity. We also explore the different impacts under different embodied carbon emission intensity distributions. The results show that global value chain participation has a significantly negative impact on the embodied carbon emission intensity. Compared with the developed “north” countries, the global value chain participation of developing “south” countries have a larger negative impact of embodied carbon emission intensity. From the perspective of different types of demand, the impact of global value chain participation on carbon emission intensity embodied in foreign exports demand is greater than that embodied in domestic demand. The quantile regression results show that the global value chain participation at the high quantiles has a greater impact on the embodied carbon emission intensity, which indicates countries with higher embodied carbon emission intensity should participate in the global value chain to expand the production scale while reducing carbon emissions. These results provide relevant material and insights to countries about how their participation in the global production fragmentation affects their greenhouse gas emission profile, which can be used to elaborate structured political measures to address, at the same time, global market inclusion and climate change mitigation.

Carbon Footprint of Lamb and Wool Production at Farm Gate and the Regional Scale in Southern Patagonia

Natural steppe grasslands are the principal food resource for sheep in the Patagonia region, reared for meat and wool. However, there is currently a concern about the relationship between ruminant livestock and climate change due to its contribution to anthropogenic greenhouse gas (GHG) emissions. The objective of this study was to determine the carbon footprints (CF) of sheep meat (lamb) and wool on a range of farms using empirical data collected on farm and then upscaled to the regional scale using models that use topographic, climatic, and vegetation indices as independent variables. At the regional level, the total CF of lamb and wool (the combination of emissions produced on farm, via transport, and via industrial processing) varied from 10.64 to 41.32 kg CO2-eq/kg for lamb meat (carcass) and from 7.83 to 18.70 kg CO2-eq/kg for fine-grade wool. For both, the predominant contribution was from primary production on-farm (75–90%), followed by industrial processing (2–15%), and transportation. We used multiple regression models to produce maps of lamb and wool CF at farm gate across Santa Cruz province. The model for variation of lamb CF explained 95% of the variance on the data and the most significant predictor variables were temperature seasonality and normalized difference vegetation index (NDVI, dimensionless). The most important variables for the model of CF of greasy wool production at farm gate were isothermality, temperature seasonality, and NDVI explained 98%. The lowest CF values of both products (lamb and wool) were located in more productive grasslands. The successful management of livestock GHG emissions becomes an important challenge to the scientific, commercial, and policy communities. The results of CF for lamb and wool production found in the present work assist in characterizing the greenhouse gas emissions profile of livestock products in Southern Patagonia by providing a baseline against which mitigation actions can be planned and progress monitored.

Calculation of the carbon footprint for family farms using the Farm Accountancy Data Network: A case from Lithuania

This study appraises the greenhouse gas (GHG) emissions for Lithuanian family farms based on the Intergovernmental Panel on Climate Change (IPCC) guidelines using Lithuanian emission factors from Lithuania’s National Inventory report (LNIR). Family farm activity data are derived from Lithuanian sample of the Farm Accountancy Data Network (FADN) for 2016. The GHG emission profile for Lithuanian family farms includes the estimates for methane (CH4) from enteric fermentation of domestic livestock population, CH4 from manure management, direct and indirect nitrous oxide (N2O) emissions from manure management, direct and indirect N2O emissions from managed soils, and carbon dioxide (CO2) from combustion of fuel. In Lithuanian family farms, on average, the key source categories of on-farms emissions were CH4 from enteric fermentation and N2O direct emissions from agricultural soils, as they together constituted 69.3% of the total emissions. The environmental pressures related to family farming were measured in terms of the Carbon Footprint (CF), which refers to the total amount of GHG produced by farming activities, and Carbon Intensity (CI) using a range of metrics including CI per land area, total output and Livestock Unit (LU). In 2016, CF stood at the average value of 57.8 t CO2eq farm−1, CI per UAA – 1.5 t CO2eq ha−1, CI per total output – 2.7 kg CO2eq EUR−1 and per LU – 6.0 t CO2eq LU−1.

Greenhouse Gas Emissions From Cropping and Grazed Pastures Are Similar: A Simulation Analysis in Australia

The agricultural sector has potential to provide greenhouse gas (GHG) mitigation by sequestering soil organic carbon (SOC). Replacing cropland with permanent pasture is one practice promoted for its potential to sequester soil carbon. However, pastures frequently support livestock, which produce other GHG emissions that could negate the abatement from increased SOC, especially given the declining rate of SOC sequestration through time. Our purpose was to determine whether the abatement provided by SOC storage in permanent pastures was offset by livestock emissions, and to thus compare emissions from grazed pasture systems with those from cropping systems. We investigated this question for three case study farms in locations with contrasting climate, soils and management representative of Australian cropping and livestock systems. Three cropping scenarios were defined that had increasing amounts of SOC inputs: Cropburn, crop residues burned before sowing (lowest SOC input); Cropstubble, crop residues retained; and Cropintensity, uncropped fallow phases replaced with short-term green manure legume crops. The on-farm GHG emissions profiles of these cropping scenarios were compared with those from two livestock scenarios utilizing continuous stocking: Livestockgrass, stocked permanent grass pasture; and Livestocklegume, stocked permanent legume pasture; the latter having higher SOC input than the former. Crop yields, pasture growth rates and emissions of carbon dioxide (CO2) and nitrous oxide (N2O) from the soil were simulated with the APSIM farming systems model. Livestock emissions were predicted using Australian GHG accounting emission factors. For the farms in this study, the SOC sequestered in the stocked permanent pastures was offset by emissions from livestock, and emissions from cropping scenarios were similar to or significantly less than those from the livestock scenarios. These findings: (1) demonstrate the importance of using net GHG abatement potentials from combined emissions rather than a single GHG abatement process when evaluating potential abatement practices, and (2) question the potential for GHG mitigation through the agricultural sector because climate and soil characteristics in different locations can alter the abatement potential of management practices, and because change in management practice can have feedbacks on other management practices and hence on GHG abatement potential.

Trade in a World Where Goods Carry Carbon Passports

In a world of rising commitments to reverse the build-up of greenhouse gas emissions and to rally behind the ultimate goal of stabilizing the planet, goods moving to and from jurisdictions with diverse climate change policies and energy structures may need to reveal where they are from and what they are made of as a way to validate their consistency with both national and global climate change action commitments. Requiring internationally traded goods to carry a carbon passport containing such information could help to build a climate-friendly global economy grounded on well-informed markets that have reliable data on the greenhouse gas (GHG) emissions embodied in goods-tracked throughout their supply chains and across borders. To make the trading system reinforce -and not undermine- the global response to climate change, we need all goods moving across borders to be identified in ways that reflect their GHG emissions impact: the balance between emissions caused over their relevant products and processes, plus or minus their respective GHG cost internalization efforts. Carbon passports aim to remedy a critical information failure in relation to traded goods-notably, helping buyers to better understand how aligned the products they are purchasing are with global (and national) climate change action commitments. This information can both influence purchasing decisions and enable differential treatment of goods in international trade based on their GHG emissions profiles.

The impacts of different façade types on energy use in residential buildings

Globally, buildings are responsible for a significant share in energy consumption and greenhouse gas emissions profiles. Various attempts are undertaken to increase the energy efficiency of buildings and reduce their environmental impact. In semi-continental climate conditions with very hot summers and extremely cold winters, buildings should be carefully designed to ensure efficient harnessing of solar energy and reducing energy loss due to poor insulation and inappropriate use of materials. Amidst the fast development of the construction industry, different façade systems are used in Kazakhstan. In several cases, the choice of the façade materials is defined not by performance but rather by economic aspects and physical appearance. This project aimed to investigate various types of façades adopted in the construction of residential buildings and assess their performance in terms of their impact on buildings’ energy consumption. The preliminary results indicate that there are five main types of façades widely used. Five different models were therefore built using energy simulation software and the respective energy consumption data were estimated. The results testify that buildings with brickwork (clay bricks) and stonework (travertine) façades were more energy efficient than those with brickwork (silica bricks), aluminum composite panels and decorated plaster façades.

Contribution of forest degradation in Indonesia’s GHG emissions: Profile and opportunity to improve its estimation accuracy

The degradation of tropical forests in Indonesia is perceived to be an essential contributor to land-based greenhouse gas (GHG) emissions, in addition to deforestation. However, the impacts of forest degradation are currently understudied and poorly understood, in comparison to deforestation, which is easier to be detected and thus more ready to be quantified and monitored. In order to understand better the contributing factors of Indonesia’s GHG emissions profiles from the forestry sector as well as taking the opportunity to tackle climate change, improving knowledge on GHG emissions from forest degradation is essential. Both literature review and simulation using a carbon accounting model were used in the analysis. National emissions profile of Indonesia has been reported to the UNFCCC, in which forest degradation has been one of the sources of emissions, although its emission value tended to be underestimated and may contain high uncertainty. It is because logging and fires in secondary forests have not been fully captured as sources of emissions, as well as post-disturbance growth that potentially enhance forest carbon stocks. This study clearly shows the importance of calculating GHG emissions from forest degradation caused by anthropogenic activities (logging, fires). It is suggested that accuracy can be improved by using a system approach that occurs in the ecosystem carbon cycle through modeling that can capture the flow of carbon following the disturbance events.

Give them credit‐the greenhouse gas performance of regional biogas systems

AbstractAnaerobic digestion to produce biogas is an important decentralised renewable energy technology. Production varies extensively between different countries and within countries, as biogas production is heavily dependent on local and regional feedstocks. In Germany, distinct regional differences can be observed. Therefore, understanding the kinds of biogas systems operating within a region is crucial to determine their greenhouse gas (GHG) mitigation potential and carbon neutrality. This is the first study to conduct an integrated life cycle assessment of biogas configurations in the landscape (biogas plants and their biomass catchments) for an entire region. RELCA a ‘REgional Life Cycle inventory Assessment’ approach was used to model the GHG mitigation potential of 425 biogas plants in the region of Central Germany (CG), aggregated to nine biogas clusters, based on feedstock mix (e.g. animal manures and energy crops) and installed capacity. GHG emission profiles were generated to compare and to identify the role of GHG credits and size of installed capacity on the mitigation performance of the regional biogas clusters. We found that smaller scaled slurry dominant clusters had significantly better GHG mitigation performance (−0.1 to −0.2 kg CO2eq kWhel−1), than larger energy crop dominant (ECdom) clusters (0.04–0.16 kg CO2eq kWhel−1), due to lower cultivation emissions and larger credits for avoided slurry storage. Thus, for the CG region larger ECdom clusters should be targeted first, to support GHG mitigation improvements to the overall future electricity supplied by the regional biogas systems. With the addition of GHG credits, the CG region is producing biogas with GHG savings (−0.15 kg CO2eq kWhel−1, interquartile range: 0.095 kg CO2eq kWhel−1). This infers that biogas production, as a waste management strategy for animal manures, could have important ramifications for future policy setting and national inventory accounting.

Bringing the Neighbourhood Into Urban Infill Development in the Interest of Well-Being

This article examines the contradictory proposed connections between compact urban form and small housing and human well-being. Whereas planners have argued the merits of smart growth and more compact urban form, compared to the traditional North American sprawling suburb, since at least the 1990s, other researchers and the global urban development community have more recently added their own evidence and argument in order to understand how not just the land use dimensions but also the transportation infrastructure design, greenhouse gas emissions profile, and social and personality characteristics may be more favourable in a compact, infill urban context than in a suburban or sprawling context. At the same time, the connection between compact urban living and well-being is not clear to many, as suburban style development expands at a faster rate than compact urban development in much of the world. Moreover, compact urban form is increasingly criticized for exerting downward pressure on liveability and well-being by exacerbating unaffordability. Taking a case based focus on the Metro Vancouver region in British Columbia, well-known for its liveability advantage and compact urban form, we present the results of survey research on resident attitudes toward and perceptions of moderate density housing being added within existing neighbourhoods. We find evidence of a tipping point, at which attitudes about new compact housing may hinge on the possibility for existing residents to have a voice in new developments and on the rate of change as much as on design or structural characteristics of the development. Perceptions of the contribution of more compact urban form and housing options to well-being should be considered central to efforts to advance such housing forms and types in cities, if these efforts are to pass the test of public opinion.

Farm-level strategies to reduce the life cycle greenhouse gas emissions of cotton production: An Australian perspective

For many agricultural commodity sectors, efforts to meet international obligations regarding emissions reduction are increasing. The Australian cotton industry has already made advances in this regard and the high yields associated with Australian cotton production dramatically minimise greenhouse gas emissions intensity. However, certainty about the quantum of greenhouse gas emissions and the relative contribution of different components of the emissions profile is somewhat unclear; and opportunities for farm-level practice change have not been fully explored. The objectives of this paper were to, (a) build a robust greenhouse gas emissions profile for the product-chain of Australian cotton fibre (lint) grown in northwest New South Wales, (b) using Life Cycle Assessment (LCA), compare the relative contributions of the different industries involved in the product-chain of cotton fibre (e.g. fertiliser producers, cotton farmers, cotton ginning plants) and (c) assess the effects of an array of on-farm mitigation options. Testing the various management options provides information for growers and policy-makers about the relative emissions reduction benefits possible. Additionally, we compared results of previous Australian cotton production studies using similar assumptions and extrapolated the emissions profile to a national scale, with the intention of informing commodity and carbon markets.The foreground data for the study were for the three production seasons from 2011-2012 to 2013–2014 in northwest New South Wales, with a functional unit of one tonne of cotton lint at port. We also drew upon published data, survey data, scientific literature and Australian and international databases. To ensure consistency between our approach and that applied to meet international emissions reporting obligations, we applied emissions formulae and factors from the Australian National Inventory Report, except where more specific published data were available. We assumed that 96% of production was from irrigated systems, with 85% of irrigation water pumped by diesel-powered irrigation pumps and a median irrigated yield of 10.3 bales per ha. We tested the sensitivity of the resulting emissions profile to a wide array of enterprise assumptions and calculation variables.The climate change impact of cotton lint on a cradle-to-port basis was 1601 kg CO2e per tonne of cotton lint. The ‘hot-spots’ within the emissions profile included the production and use of synthetic nitrogen (N) fertilisers (46% of emissions), the production and use of electricity and diesel used for irrigation (10%) and the production and use of diesel for farm machinery (9%).Farm level management options with potential to minimise life cycle GHG emissions were: reducing N fertiliser rate from a commercial rate of 255 kg N/ha to 240 kg N/ha or 180 kg N/ha (2.6% and 13.2% emissions reduction); use of controlled-release and stabilised N fertilisers (5.9% reduction), changing from diesel to solar-powered irrigation pumps (8.1% reduction), changing from diesel to biofuel-powered farm machinery (3.4% reduction), changing from continuous cotton to a cotton-legume crop rotation (3.9% reduction) and use of N fertigation (2.1% reduction). Whilst we focused on farm-level mitigation strategies, these changes were placed in the context of the cradle-to-gate system, to account for associated changes in pre-farm and post-farm emissions.

Greenhouse gas emissions of different fly ash based geopolymer concretes in building construction

Replacing virgin materials with recycled or sustainable materials to reduce energy consumptions and emissions is the focus of contemporary research to reduce building related emissions. Geopolymer concrete produced using 100% fly ash is a similar sustainable construction material capable of replacing Portland Cement (PC) concrete. As a replacement for PC, fly ash seems to be a sustainable solution, however the benefits from the production process of fly ash geopolymer (FAGP) concrete is the subject of considerable debate. In addition, factors such as local availability and transportation issues could potentially increase the emission profile of FAGP concrete. Thus, this study aims to evaluate the emission profiles for different types of fly ash in Australia considering availability and transportation. A case study and a scenario analysis are also presented to demonstrate the factors that affect the Green House Gas (GHG) emission profile of FAGP manufacture. The results indicate that to the GHG emission profile for FAGP concrete changes considerably based on the material availability, transportation and mix design. Alkali activators and elevated heat curing processes also significantly contribute the total GHG emissions of FAGP concrete production. The results further signify that the case study location could influence the employment of FAGP concrete in terms of GHG emissions. Further studies are encouraged on optimising the cost, GHG emissions, availability and strength characteristics to strike a balance between in sustainability for selecting the best FAGP type for construction. The results also provide the initial factors to be considered in developing a guideline for employing sustainable materials in the building industry.

Greenhouse Gas Emissions from Freshwater Reservoirs: What Does the Atmosphere See?

Freshwater reservoirs are a known source of greenhouse gas (GHG) to the atmosphere, but their quantitative significance is still only loosely con- strained. Although part of this uncertainty can be attributed to the difficulties in measuring highly variable fluxes, it is also the result of a lack of a clear accounting methodology, particularly about what constitutes new emissions and potential new sinks. In this paper, we review the main processes involved in the generation of GHG in reservoir systems and propose a simple approach to quantify the reservoir GHG footprint in terms of the net changes in GHG fluxes to the atmosphere induced by damming, that is, 'what the atmosphere sees.' The approach takes into account the pre-impoundment GHG balance of the landscape, the temporal evolution of reservoir GHG emission profile as well as the natural emissions that are displaced to or away from the reservoir site resulting from hydrological and other changes. It also clarifies the portion of the reservoir carbon burial that can potentially be considered an offset to GHG emissions.