Mt Of CO2 Eq Research Articles

Carbon footprint analysis for Sunway University campus

Carbon footprint can be quantified from the emission of carbon dioxide gas (CO 2) through human activities, whereby it has impacted the environment. Burning of crude oil as a main source of fuel for combustion to provide energy for transportation and electricity production, releases various Greenhouse gas (GHG), mainly CO 2 gas. Hence, a study was conducted at Sunway University to calculate its carbon emission from electricity consumption and transportation usage by campus dwellers (Sunwayians) whereby CO 2 equivalent (CO 2eq) computations were performed on monthly electricity consumption for the year 2018 till 2019 and the number of vehicles parked within the campus. Behavioural and awareness studies were performed based on survey questionnaires. Results indicated that the total Carbon Footprint from CO 2 emission for electricity consumption were 10,369 MTCO 2eq and 10,005 MTCO 2eq for year 2018 and 2019, respectively while emission from transportations scored 0.383 MTCO 2eq per day. The survey showed that a significant correlation

Potential of Tailing Deposits in Chile for the Sequestration of Carbon Dioxide Produced by Power Plants Using Ex-Situ Mineral Carbonation

In this study, the potential of copper tailing deposits in Chile for the sequestration of carbon dioxide (CO2) via ex-situ mineral carbonation integrating the recovery of valuable metals was assessed. An inventory of tailing deposits and CO2 sources existing in Chile was constructed to determine the most suitable site for the installation of a future mineral carbonation plant and to evaluate the technical, economic, and environmental feasibility of CO2 capture, separation, and transport from the source to the mineral carbonation plant. The data of the inventory of tailings deposits in Chile were obtained from the National Service of Geology and Mining. For the thermoelectric plants installed in Chile, data of energy production were obtained from the Energy National Commission. Through the use of the technique for order preference by similarity to ideal solution (TOPSIS) method and sensitivity analysis, the optimum location in the region of Antofagasta to install a mineral carbonation plant was identified. In addition, the results show that in the region of Antofagasta five tailing deposits have the potential to sequester between 66 to 99 Mt of CO2. Meanwhile, thermoelectric plants in 2018 produced about 9.4 Mt of CO2 that is available to be sequestered, with a maximum generation potential of 21.9 Mt of CO2eq per year. The methodology and the study presented can be considered as a preliminary study to identify tailings that require further analysis.

Integrated nutrient management - promising way to reduce carbon dioxide and methane emission in flooded rice ecosystem: A review

Climate change is an inevitable ruling issue caused by the increasing concentration of greenhouse gases (GHG’s) in the atmosphere worldwide. It will have a considerable impact on agriculture and its related fields like live stocks and fisheries. In India, the main sectors contributing to these emissions are industry, agriculture and waste, with a total emission of 334 MT CO2 eq. Besides, the major sources in agriculture are enteric fermentation (63.4%), rice cultivation (20.9%), agricultural soils (13.0%), manure management (2.4%) and on-field burning is the crop residue (2.0%). Thus, the crop productivity sector (rice cultivation, soil and field burning of crop residues) contributes 35.9% to the total emission from agriculture. Therefore, reducing GHG emissions and enhancing the C sequestration in soil and biomass has become challenging. However, the total GHG’s emission from all sectors of the country has decreased from 33% in 1970 to 18% in 2010. Cutting off GHGs emission from agriculture can be achieved by sequestering C and reducing methane emissions(CH4) and carbon dioxide(CO2) through various soil and crop management strategies. Integrated nutrient management (INM) practice ensures the Soil –plant –atmospheric continuum (SPAC) in a promising way, reducing the GHGs emission by sequestering more carbon to soil than emissions. A studious prominent INM solution can be identified to develop a mitigation strategy that helps in climate change adaptation and sustains soil health through soil carbon sequestration.

Development of a framework for the assessment of the market penetration of novel in situ bitumen extraction technologies

Greenhouse gas (GHG) mitigation opportunities from emerging in situ mining technologies in oil sands production can play a role in reducing global warming. There is limited research on quantitative assessments of the penetration of emerging oil sands technology in the energy sector. This study addresses this gap by developing a novel framework (MAPL-OET) to assess the market penetration of emerging oil sands extraction technologies. The framework is robust and data-intensive as it combines diffusion models, econometrics models, cost models, and energy-economy equilibrium models. The combined model evaluates the adoption of new energy technologies resulting from carbon price measures and other economic factors, as well as the GHG mitigation potential in the oil sands sector. The accumulated GHG mitigation potential from high carbon and BAU scenarios (i.e., a carbon price of $30/tonne of CO2 in 2030, increasing at a rate of 4%/yr to reach about $105/tonne of CO2) was estimated to be 192.8 Mt of CO2 eq between 2018 and 2050. New extraction technologies also improve average energy intensities by 1.3% annually in the high carbon price scenarios. The developed new framework can help public and private organizations to achieve energy or environmental targets.

Synthesis and Characterization of (Co,Ni)O Solid Solutions As Protective Coatings for Inert Anodes in Aluminum Electrolysis

The industrial production of primary aluminum from alumina ore (Al2O3) is still carried out by the Hall-Héroult process. The process relies on dissolving alumina in an electrolyte consisting mainly of liquid Na3AlF6 at 950-1000 °C. While the reduction of dissolved Al3+ ions in aluminum occurs at the cathode, the complementary reaction occurs at a carbon anode that is consumed to form carbon dioxide, which necessitates its regular replacement (every 25 days). The overall reaction is the following:Canadian aluminum smelters produce annually about 6 Mt of CO2 eq(reported in 2017), which is equivalent to the CO2 amount generated annually by about 2 million cars.The substitution of consumable carbon anodes with inert (O2-evolving) anodes in the electrochemical cells to produce aluminium would have significant environmental benefits because it would eliminate the emissions of carbon dioxide and perfluorocarbons associated with the consumption of the carbon anode. However, the design of inert anodes is a major challenge because of the severe Al electrolysis conditions (cryolithic medium at 960 °C), which requires materials with excellent resistance to corrosion and thermal shock as well as adequate electrochemical properties [1].Single phase Cu65Ni20Fe15 alloy is a promising inert anode for Al production due to its ability to form a protective NiFe2O4 layer upon Al electrolysis. However, its corrosion resistance is still insufficient and a protective layer is required to prevent the penetration of electrolyte into the nickel ferrite layer and the formation of fluorides during Al electrolysis [2-4].In this context, the use of (Co,Ni)O-based protective coatings for metallic anode appears promising [5]. However, it is challenging to prepare a single phase, coherent and crack-free oxide layer as required for industrial Al production. A potentially relevant method to produce (Co,Ni)O coated inert anodes is by direct deposition of (Co,Ni)O oxide compounds by spray deposition techniques such as suspension plasma spray (SPS) and high velocity oxygen fuel (HVOF). These additive manufacturing deposition are well-established technologies for producing protective oxide coatings for various industrial applications (e.g. gas turbines).As a first step toward this goal, pure CoxNi1−xO solid solutions have been prepared over the whole composition range by a two-step procedure that consisted of high-energy ball milling followed by a heat treatment of Co3O4 and NiO powders [6]. Then, the thermal stability and electrical conductivity of (Co,Ni)O solid solutions were determined at temperatures ranging between 700 and 1000 °C. Also, their dissolution rate was measured in K-based cryolite at 700 °C and in Na-based cryolite at 1000 °C.In a second step, (Co,Ni)O powders have been used as raw materials for the thermal spraying (HVOF and SPS) of protective coatings onto Cu-Ni-Fe inert anodes [7]. The morphological and microstructural characteristics of the coating depending on the thermal spray conditions will be presented. The oxidation behaviour of the coated inert anodes under air and argon is presented. Preliminary investigation of the electrochemical behaviour under Al electrolysis conditions of the (Co,Ni)O/Cu-Ni-Fe anodes will be also presented and discussed.

Convenience versus sustainability

Convenience versus sustainability

Techno-environmental analysis of battery storage for grid level energy services

With more and more renewable energy sources (RES) going into power grids, the balancing of supply and demand during peak times will be a growing challenge due to the inherent intermittency and unpredictable nature of RES. Grid level batteries can store energy when there is excess generation from wind and solar and discharge it to meet variable peak demand that is traditionally supplied by combined cycle gas turbine (CCGT) plants. This paper assesses the potential of battery storage to replace CCGT in responding to variable peak demand for current and future energy scenarios (FES) in the UK from technical and environmental perspectives. Results from technical analysis show that batteries, assuming size is optimised for different supply and demand scenarios proposed by the National Grid, are able to supply 6.04%, 13.5% and 29.1% of the total variable peak demand in 2016, 2020 and 2035, respectively while CCGT plants supply the rest of the demand. Particularly, to phase out CCGT variable generation from the UK grid in 2035, electricity supply from wind and solar needs to increase by 1.33 times their predicted supply in National Grid's FES. The environmental implications of replacing CCGT by batteries are studied and compared through a simplified life cycle assessment (LCA). Results from LCA studies show that if batteries are used in place of CCGT, it can reduce up to 87% of greenhouse gas emissions and that is an estimated 1.98 MtCO2 eq. for an optimal supply, 29.1%, of variable peak demand in 2035.

Electrodeposited TiB2 Coating on Graphite As Wettable Cathode for Al Production

Greenhouse gas (GHG) emission from the Canadian aluminum industry was about 6 Mt of CO2 eq in 2017, an amount equivalent to the GHG emitted by about 1.3 million cars [1-2]. The use of inert anodes, like Ni-Fe-Cu alloys [3], instead of carbon anodes to produce O2 rather than CO2 during aluminum electrolysis is paramount to curb GHG emissions from that industry. However, to maintain the energy efficiency of the process, the opposite cathode material must be wetted by molten aluminum to decrease the anode-to-cathode distance and thus reduce the overall cell voltage. TiB2 presents a good wettability by molten Al. Also, it has good electrical conductivity and good chemical stability under Al electrolysis. Accordingly, TiB2 is considered as an interesting cathode material to use in conjunction with inert anodes. However, its production as dense bulk cathode is challenging.In this work, the electrodeposition of TiB2 on graphite substrate was performed by periodically interrupted current method in a molten LiF-NaF-KF salt at 600°C containing K2TiF6 and KBF4 as titanium and boron precursors, respectively [4]. The impact of the electrodeposition parameters on the crystalline structure, morphology, adhesion strength, Al wettability and Al penetration resistance of the TiB2 deposits will be presented.[1] 2017 sustainable development report. Aluminium Association of Canada.[2] Greenhouse Gas Emissions from a Typical Passenger Vehicle. United States Environnemental Protection Agency, 2018[3] S. Helle, M. Pedron, B. Assouli, B. Davis, D. Guay, L. Roué, Structure and high-temperature oxidation behaviour of Cu–Ni–Fe alloys prepared by high-energy ball milling for application as inert anodes in aluminium electrolysis. Corros. Sci. 52 (2010) 3348.[4] G. Ett, E.J. Pessine, Electrochim. Acta. 44 (1999) 2859. Figure 1: (A) SEM cross-section image of electrodeposited TiB2 coating on graphite substrate. Optical images of Al droplet at 1000 °C on (B) TiB2-coated and (C) pure graphite substrates.Fig Figure 1

Synthesis and Characterization of (Co,Ni)O Solid Solutions As Protective Coatings for Inert Anodes in Aluminum Electrolysis

The industrial production of primary aluminum from alumina ore (Al2O3) is still carried out by the Hall-Héroult process. The process relies on dissolving alumina in an electrolyte consisting mainly of liquid Na3AlF6 at 950-1000 °C. While the reduction of dissolved Al3+ ions in aluminum occurs at the cathode, the complementary reaction occurs at a carbon anode that is consumed to form carbon dioxide, which necessitates its regular replacement (every 25 days). The overall reaction is the following: Al2O3 + 3/2 C= 2 Al + 3/2 CO2 Canadian aluminum smelters produce annually about 6 Mt of CO2 eq(reported in 2017), which is equivalent to the CO2 amount generated annually by about 2 million cars.The substitution of consumable carbon anodes with inert (O2-evolving) anodes in the electrochemical cells to produce aluminium would have significant environmental benefits because it would eliminate the emissions of carbon dioxide and perfluorocarbons associated with the consumption of the carbon anode. However, the design of inert anodes is a major challenge because of the severe Al electrolysis conditions (cryolithic medium at 960 °C), which requires materials with excellent resistance to corrosion and thermal shock as well as adequate electrochemical properties [1].Single phase Cu65Ni20Fe15 alloy is a promising inert anode for Al production due to its ability to form a protective NiFe2O4 layer upon Al electrolysis. However, its corrosion resistance is still insufficient and a protective layer is required to prevent the penetration of electrolyte into the nickel ferrite layer and the formation of fluorides during Al electrolysis [2-4].In this context, the use of (Co,Ni)O-based protective coatings for metallic anode appears promising [5]. However, it is challenging to prepare a single phase, coherent and crack-free oxide layer as required for industrial Al production. A potentially relevant method to produce (Co,Ni)O coated inert anodes is by direct deposition of (Co,Ni)O oxide compounds by spray deposition techniques such as suspension plasma spray (SPS) and high velocity oxygen fuel (HVOF). These additive manufacturing deposition are well-established technologies for producing protective oxide coatings for various industrial applications (e.g. gas turbines).As a first step toward this goal, pure CoxNi1−xO solid solutions have been prepared over the whole composition range by a two-step procedure that consisted of high-energy ball milling followed by a heat treatment of Co3O4 and NiO powders [6]. Then, the thermal stability and electrical conductivity of (Co,Ni)O solid solutions were determined at temperatures ranging between 700 and 1000 °C. Also, their dissolution rate was measured in K-based cryolite at 700 °C and in Na-based cryolite at 1000 °C.In a second step, (Co,Ni)O powders have been used as raw materials for the thermal spraying (HVOF and SPS) of protective coatings onto Cu-Ni-Fe inert anodes. The morphological and microstructural characteristics of the coating depending on the thermal spray conditions will be presented. Preliminary investigation of the electrochemical behaviour under Al electrolysis conditions of the (Co,Ni)O/Cu-Ni-Fe anodes will be also presented and discussed.

(Co,Ni)O Coated Anodes for CO2-Free Al Production

Canadian aluminum production is an important source of greenhouse gases (GHGs) with 6 Mt of CO2 eq emitted in 2017, which is equivalent to the amount of GHG generated annually by about 2 million cars. The current technology consumes carbon anodes during the electrolysis of aluminum to form CO2 according to the overall reaction: Al2O3 + 3/2 C = 2 Al + 3/2 CO2. The most effective solution would be to replace the consumable carbon anodes with so-called inert anodes that emit O2 rather than CO2 and that are based on the following overall reaction: Al2O3 = 2 Al + 3/2 O2. This would reduce GHGs by 75 to 100% depending on the type of emissions (CO2, CFx, NOx, SOx, etc.). However, the design of inert anodes is a major challenge because of the severe conditions during aluminum electrolysis that require materials with excellent corrosion and thermal shock resistance while having the same adequate electrochemical properties [1].Among inert anodes studied so far, Cu-Ni-Fe-based alloys appear to be the most promising owing to their ability to form a layer of nickel ferrite (NiFe2O4) on the surface of the anode upon Al electrolysis [2-4]. This nickel ferrite has low solubility in a cryolithic medium. However, the formation of the nickel ferrite protective layer is slow and, depending on the experimental conditions, might not be formed fast enough to provide effective protection of the underlying substrate Cu-Ni-Fe alloy. One strategy to help in the formation of this layer is to coat the Cu-Ni-Fe alloy with a sacrificial layer that would be stable for a period long enough to allow the formation of NiFe2O4 on the surface of the anode.In this context, the use of (Co,Ni)O-based protective coatings for metallic anode appears promising [5]. However, it is challenging to produce coherent and crack-free oxide layer as required for industrial Al production. A potentially relevant method to produce (Co,Ni)O coated inert anodes is by direct deposition of (Co,Ni)O oxide compounds by thermal spray techniques such as suspension plasma spray (SPS) and high velocity oxygen fuel (HVOF). They are well-established technologies for producing protective oxide coatings for various industrial applications (e.g. gas turbines). Additionally, thermal spray could be used on Al production site to restore protective (Co,Ni)O coating on end-of-life inert anodes.As a first step toward this goal, single phase (Co,Ni)O powders with various Co/Ni ratios that could be used as raw materials for the thermal spraying of protective coatings onto Cu-Ni-Fe inert anodes have been produced [6]. The crystalline structure, thermal stability, electrical conductivity and solubility in cryolite media of the produced (Co,Ni)O powders are characterized depending on their Co/Ni ratio. Finally, selected (Co,Ni)O powders have been used as raw materials for the thermal spraying (HVOF and SPS) of protective coatings onto Cu-Ni-Fe inert anodes and the electrochemical behaviour of the coated inert anodes under Al electrolysis conditions is presented.

Short-term effects of PV integration on global welfare and CO2 emissions. An application to the Iberian electricity market

This work analyses the effect on the daily electricity market of the authorisation of 3909 MW of new photovoltaic (PV) power in Spain in 2017 –as a contribution to the EU environmental objectives for 2030. To estimate the impact of this additional offer, we use real data from the supply and demand curves of the Iberian (Spain and Portugal) daily electricity market. Our data is available for all the hours of the full year between August 1, 2016 and July 31, 2017. In this period, more than 800 agents have participated in the market, generating more than 15 million operations. In order to calculate the new supply function for each hour, the hourly production of these new facilities is added to the offer at zero price, since their marginal costs are very close to zero and correspond to the offers that are being made by the current PV bidders. By using static and dynamic (multilevel) analyses, the variations of prices, quantities, emissions and surpluses of buyers and sellers are calculated. As the economic theory foresees, the new supply curve causes a decrease in average prices of 2.7 €/MWh in daylight hours (or 1.5€/MWh considering all the hours of the year), and an 8% reduction in the income of the PV plants currently in operation (incumbents). The substitution of combined cycle energy (the technology expulsed) by PV energy brings about a saving of 2.2 million Mt of CO2 eq. In terms of economic welfare, the incorporation of PV power produces an increase in the total surplus of about 300 M€ each year.

Replacing SF6 in Electrical Gas-Insulated Switchgear: Technological Alternatives and Potential Life Cycle Greenhouse Gas Savings in an EU-28 Perspective

To date, atmospheric concentrations of sulfur hexafluoride (SF6) are the most potent among the greenhouse gases identified by the Intergovernmental Panel on Climate Change (IPCC) and are still rising. In the EU-28, SF6 has been banned from several applications, however, an important exception is gas-insulated electrical switchgear (GIS) for which cost-effective and environmentally sound alternatives were unavailable when the F-Gas regulation was last revised in 2014. To date, after some recent innovations, we argue that the phasing out of SF6 could spur the accelerated development of alternatives with a lower carbon footprint. In the EU-28, the SF6 amount in switchgear is unclear. In this paper, we estimated the SF6 amount to be between 10,800 and 24,700 t (with a mode at 12,700 t) in 2017, resulting in 68 to 140 t of annual emissions from operational leakage only, corresponding to 1.6 to 3.3 Mt of CO2-eq. We additionally calculated the potential greenhouse gas savings over the lifecycle of one exemplary 145 kV gas-insulated switchgear bay upon replacing SF6 by decafluoro-2-methylbutan-3-one (C5-FK) and heptafluoro-2-methylpropanenitrile (C4-FN) mixtures. Projecting these results over the EU-28, a phase-out scenario starting from 2020 onwards could reduce the carbon footprint by a median of 14 Mt of CO2-eq, over a period of 50 years. Extrapolation to medium voltage could be assumed to be of a similar magnitude.

Assessment of environmental impact of FOOD waste in Turkey

Abstract Food waste is a multifaceted problem that has negative impacts on the environment. Life cycle assessment (LCA) is a tool that shows these environmental impacts as quantifiable and is able to interpret the results with an integrated approach. In this study, LCA was used to analyze food waste in Turkey from a bottom up processing perspective. In order to assess the environmental impact of food waste on climatic, water, and energy resources, we calculated the embedded carbon, water, and energy footprints throughout the food supply chain in Turkey. Avoidable food waste was calculated as 16 Mt in Turkey in the year 2016. It is estimated that food waste in Turkey embodied 23.7 Mt of CO2-eq, 6.2 × 109 m³ of water and 13.5 ×10⁴ TJ of energy. The results obtained by this research could be used to assess the linkage between food waste and the carrying capacity of resources.

Utilising carbon dioxide for transport fuels: The economic and environmental sustainability of different Fischer-Tropsch process designs

Producing fuels and chemicals from carbon dioxide (CO2) could reduce our dependence on fossil resources and help towards climate change mitigation. This study evaluates the sustainability of utilising CO2 for production of transportation fuels. The CO2 feedstock is sourced from anaerobic digestion of sewage sludge and the fuels are produced in the Fischer-Tropsch (FT) process. Using life cycle assessment, life cycle costing and profitability analysis, the study considers four different process designs and a range of plant capacities to explore the effect of the economies of scale. For large-scale plants (1,670 t/day), the FT fuels outperform fossil diesel in all environmental impacts across all the designs, with several impacts being net-negative. The only exceptions are ozone depletion, for which fossil diesel is the best option, and global warming potential (GWP), which is lower for fossil diesel for some process designs. Optimising the systems reduces the GWP of FT fuels in the best case by 70% below that of fossil diesel. Assuming a replacement of 9.75–12.4% of fossil diesel consumed in the UK by 2,032, as stipulated by policy, would avoid 2–8 Mt of CO2 eq./yr, equivalent to 2–8% of annual emissions from transportation. However, these fuels are not economically viable and matching diesel pump price would require subsidies of 35–79% per litre. Optimising production yields would allow decreasing the subsidies to 8%. Future research should be aimed at technology improvements to optimise these systems as well as evaluating different policy mechanisms needed to stimulate markets for CO2-derived fuels.

Environmental Assessment of Alternatives for Biowaste Treatment in Mexico City

This paper aims to determine the environmental performance of the current landfill gas management system (based on flaring) in Mexico City (Bordo Poniente) in comparison to the collection of biogas generated from solid waste through one of the most innovative technology implemented in Denmark (Aikan Tecnology), which produces biogas and digestate from waste. Two alternative scenarios are proposed in which the Aikan Technology is implemented in Bordo Poniente to replace the existing system (reference scenario) that involves landfilling inorganic waste and composting organic waste in Bordo Poniente with no biogas recovery. The biogas recovered through Aikan Technology is exploited to provide heat and electricity (Scenario 1) or biofuel for the transportation sector (Scenario 2). A comparative life cycle assessment (LCA) was performed to evaluate the environmental performances associated with all scenarios by evaluating the impact categories Climate Change, Fossil Depletion, and Cumulative Energy Demand. According to the waste capacity of Bordo Poniente, the implementation of the Aikan Technology would result in a total annual reduction of 0.14 and 0.08 Mt of CO2 eq for Scenario 1 and Scenario 2, respectively. Scenario 1 was also the best performing scenario with respect to fossil depletion (-52 kg oil eq ton-1 of organic waste) and cumulative energy demand (-3557 MJ ton-1 of organic waste). The implementation of Aikan Technology in Mexico City represents an important challenge and requires further research into its economic and political feasibility. When it comes to tackling global environmental problems, international agreements ascribe high importance to environmental technology transfer. This study represents a preliminary step in terms of environmental assessment and thus provides important information for policymakers attempting to achieve more sustainable management of solid waste in Mexico.

Algerian energy policy and potential to reducing greenhouse gas emissions

ABSTRACTIn Algeria, energy consumption is growing rapidly. Due to the high demand and declining conventional energy resources, the country developed a new energy policy based on the promotion of renewable energies and CO2 mitigation. For this purpose, the authorities have taken new steps to reinforce the legislative and institutional framework and put in place a favorable financial support. In addition, an ambitious program to develop solar energy and energy efficiency was adopted recently. The objective of this strategy is to achieve by 2030 a 40% share of solar electricity and to contribute, voluntarily, to reducing greenhouse gas (GHG) emissions. In this work, we present an analysis of the current situation and its projection to 2030 and we examine the available opportunities to reduce significantly GHG emissions. The study presents the magnitude of emissions in 2008 and 2012, the temporal evolution of CO2 and particularly what will be the impact on GHG emissions of the new strategy. The results show that, in 2012, GHG emissions totaled 153 MT CO2 eq. and growing at a rate of over 3%. However, there is a high potential for mitigation, especially in energy sectors, in building, transportation, as well as waste management and gas flaring. Two scenarios are developed: with implementation of solar energy and without. This analysis shows that the overall potential of CO2 mitigation will rise in 2030 to about 300 MT CO2 eq.

An Analysis of the Climate Change Mitigation Potential through Soil Organic Carbon Sequestration in a Corn Belt Watershed.

Land-based carbon sequestration constitutes a major low cost and immediately viable option in climate change mitigation. Using downscaled data from eight atmosphere-ocean general circulation models for a simulation period between 2015 and 2099, we examine the carbon sequestration potential of alternative agricultural land uses in an intensively farmed Corn Belt watershed and the impact of climate change on crop yields. Our results show that switching from conventional tillage continuous corn to no-till corn-soybean can sequester the equivalent of 192.1 MtCO2 eq of soil organic carbon per hectare with a sequestration rate of 2.26 MtCO2 eq ha-1 yr-1. Our results also indicate that switchgrass can sequester the equivalent of 310.7 MtCO2 eq of soil organic carbon per hectare with a sequestration rate of 3.65 MtCO2 eq ha-1 yr-1. Our findings suggest that, unlike for corn and soybean yields, climate change does not have a significant effect on switchgrass yields, possibly due to the carbon fertilization effect.

Sustainable manufacturing of consumer appliances: Reducing life cycle environmental impacts and costs of domestic ovens

Electric ovens are among the least energy efficient appliances, with the efficiency of only 10%–12%. With new policy instruments in Europe requiring energy reduction, manufactures are seeking to develop more efficient domestic appliances. The aim of this paper is to aid sustainable manufacturing of an innovative, highly-efficient oven (HEO) by evaluating its life cycle environmental impacts and costs in comparison to conventional ovens. The results suggest that the HEO has 9%–62% lower environmental impacts than conventional ovens with the equivalent savings in the life cycle costs ranging from 25% to 61%. Replacement of conventional ovens by HEO in Europe (EU28) would save 0.5–5.2 Mt of CO2 eq. and the life cycle costs would be lower by €0.5–1.96 billion (109) per year. At the household level, energy consumption would be reduced by up to 30% and consumer costs by 25%–50%. These results suggest that policy measures should be put in place to encourage the uptake of energy efficient ovens by consumers.

Consumption-weighted life cycle assessment of a consumer electronic product community.

A new approach for quantifying the net environmental impact of a "community" of interrelated products is demonstrated for consumer electronics owned by an average U.S. household over a 15-year period (1992-2007). This consumption-weighted life cycle assessment (LCA) methodology accounts for both product consumption (number of products per household) and impact (cumulative energy demand (MJ) and greenhouse gas emissions (MT CO2 eq) per product), analyzed using a hybrid LCA framework. Despite efficiency improvements in individual devices from 1992 to 2007, the net impact of the entire product community increased, due primarily to increasing ownership and usage. The net energy impact for the product community is significant, nearly 30% of the average gasoline use in a U.S. passenger vehicle in 2007. The analysis points to a large contribution by legacy products (cathode ray tube televisions and desktop computers), due to historically high consumption rates, although impacts are beginning to shift to smaller mobile devices. This method is also applied to evaluate prospective intervention strategies, indicating that environmental impact can be reduced by strategies such as lifespan extension or energy efficiency, but only when applied to all products owned, or by transforming consumption trends toward fewer, highly multifunctional products.

CH4 and N2O emissions embodied in international trade of meat

Although previous studies have quantified carbon dioxide emissions embodied in products traded internationally, there has been limited attention to other greenhouse gases such as methane (CH4) and nitrous oxide (N2O). Following IPCC guidelines, we estimate non-CO2 emissions from beef, pork and chicken produced in 237 countries over the period 1990–2010, and assign these emissions to the country where the meat is ultimately consumed. We find that, between 1990 and 2010, an average of 32.8 Mt CO2-eq emissions (using 100 year global warming potentials) are embodied in beef, pork and chicken traded internationally. Further, over the 20 year period, the quantity of CO2-eq emissions embodied in traded meat increased by 19%. The largest trade flows of emissions embodied in meat were from Brazil and Argentina to Russia (2.8 and 1.4 Mt of CO2-eq, respectively). Trade flows within the European region are also substantial: beef and pork exported from France embodied 3.3 Mt and 0.4 Mt of CO2-eq, respectively. Emissions factor of meat production (i.e. CO2-eq emissions per kg of meat) produced depend on ambient temperature, development level, livestock category (e.g. cattle, pork, and chicken) and livestock management practices. Thus, trade may result in an overall increase of GHG emissions when meat-consuming countries import meat from countries with a greater emissions intensity of meat production rather than producing the meat domestically. Comparing the emissions intensity of meat production of trading partners, we assess trade flows according to whether they tend to reduce or increase global emissions from meat production.