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The increasing contribution of refrigeration systems to global warming has led to widespread demand for low global warming potential (GWP) refrigerants as alternatives. This paper proposed a comprehensive environmental assessment method for evaluating the carbon footprint of units charged with low-GWP refrigeration. Experimental and numerical studies were used to investigate the carbon footprint impact of using alternative refrigerants at different ambient temperatures in China. Initially, the model was validated through experimental case studies on the use stage of cold storage units. Subsequently, a comparison was made between the cooling capacity (CC) and energy efficiency ratio (EER) of cold storage units charged with different refrigerants. Additionally, the impact of alternative refrigerants in the use stage was analyzed by numerical calculations, and the adaptability of the cold storage unit to the ambient temperature and the national energy structure was also studied. The results indicate that among the four stages of the cold storage unit, the use stage is the hotspot of carbon footprint due to the large amount of energy consumption and the existence of refrigerant leakage and other behaviors. Utilizing low-GWP alternative refrigerants could significantly reduce the carbon footprint of the cold storage units' use stage by 10.56%–16.39%, thereby lowering the whole stage carbon footprint. Furthermore, the ambient temperature and national energy structure could also effectively reduce the carbon footprint of cold storage units' whole stage by 1%–27.17%. Furthermore, after adopting low GWP refrigerants, the life-cycle cost (LCC) of the units have also decreased by 6.1%–12%. Taking into account both environmental impact and economic considerations, it is recommended to directly replace R404A with R448A in the units in regions where the average ambient temperature is above 15 °C. • A carbon footprint evaluation model for the units was established. • Influencing factors of carbon footprint are studied numerically and experimentally. • By GHG assessments, the optimal refrigerant and external conditions were determined. • Alternative refrigerants reduce carbon emissions for cold storage units by 8.8%–24.92%. [ABSTRACT FROM AUTHOR]

Electric arc furnace (EAF) steelmaking process is an environmentally friendly, energy saving, and low-carbon route to produce steel, but its further development is restricted by extensive electricity consumption in China. In this paper, the EAF steelmaking processes driven by solar energy system (EAF-SES) was developed, which supplies electricity for the whole process, and reduce the dependence on traditional energy sources. Life cycle assessment and techno-economic analysis of EAF steelmaking processes integrated with traditional energy system (EAF-TES) and EAF-SES was conducted according to the data of 1536 heats based on the function unit of 1000 kg of molten steel (MS). EAF-SES and EAF-TES were studied and compared from perspectives of life cycle carbon footprint (LCCF), production cost (PC), raw materials cost (RMC), solar energy price (SEP), and carbon tax (CT). The results indicated that EAF-SES enjoyed lower LCCF but higher PC than EAF-TES. The LCCF of EAF-SES was 220 kg lower than that of EAF-TES. Besides, compared to the PC of 478 $ per ton of MS in EAF-TES, the PC in EAF-SES increased by 9.13%. While the electricity price was lower than 0.041 $/kWh or CT higher than 217 $/t CO 2 , respectively, EAF-SES had both significant advantages of economic and environmental benefits. Vigorously employing clean energy power generation, cutting down hot metal supply, and adopting full scrap melting mode in EAF steelmaking processes achieve better environmental performance. This research is expected to supply a technical idea for energy conservation, emission reduction, and cleaner production in future iron and steel industry. [Display omitted] • EAF steelmaking process integrated with solar energy system (EAF-SES) was developed. • Comparative life cycle assessment and techno-economic analysis of EAF-SES was conducted. • Life cycle inventories of 1536 heats in EAF steelmaking process in China were converged. • Some methods of energy conservation and emission reduction in EAF steelmaking process were brought out. [ABSTRACT FROM AUTHOR]

Within the context of climate change and population growth, the development of urban agriculture is of great environmental and economic significance in rapidly urbanizing China. Based on the primary survey data, this paper evaluated the carbon footprint (CF) and economic efficiency of urban agriculture in Beijing (China) using the life cycle assessment method (from cradle to consumption approach). Two cases were analyzed and compared considering their differences in on-farm cultivation and off-farm supply chains: a conventional small householder farm that sells its vegetables directly to consumers in a local market, and a large home-delivery agriculture (HDA) initiative that delivers its vegetables to the consumers' home directly. Both cases were equipped with greenhouses with plastic covering but no heating system. The CF of the production, transportation and distribution of 1 kg fresh vegetables was estimated at 0.318 kg CO 2 -eq kg−1 and 0.624–0.652 kg CO 2 -eq kg−1 for conventional and HDA initiative farm, respectively. However, the HDA initiative showed a better environmental performance than the conventional operation when taking economic efficiency into consideration. The CF per unit of profit of HDA initiative (0.093–0.097 kg CO 2 -eq per CNY) was lower than conventional farm (0.111 kg CO 2 -eq per CNY). The lower CF per unit of product weight of the conventional farm was largely attributed to the high yield and the lower CF per unit of profit of the HDA initiative was mainly due to the outstanding economic profitability through income optimization. The major hotspots of CF in both cases were greenhouse plastic films in the cultivation phase (from cradle to farm gate) and transportation in the supply chain (from farm gate to consumption). Simulation of a switch to biodiesel instead of gasoline and diesel in combination with the replacement of current fossil-fuel-dominated electricity by hydro-powered electricity resulted in 20.0–21.8% reduction in the total CF. By identifying the CF hotspots of two farm cases, particular inputs and activities can be targeted for adjustment in order to effectively reduce the CF of urban agriculture in Beijing. [ABSTRACT FROM AUTHOR]

Due to unclear research boundaries and a confusion between direct and indirect emissions, the impact of the circular economy (CE) on carbon emissions needs to be researched in depth. In this paper, we use a life cycle model based on carbon emissions and carbon reduction to build an emissions (reduction) matrix for the carbon footprint (CF) of coal-fuelled power generation, and then calculate the life cycle carbon emissions from China's coal-fuelled power CE parks. Results show that carbon emissions from China's coal-fuelled power at the industrial park level follow the trend of raw coal production and consumption, increasing from 2000 to a maximum of 3.25 billion tCO 2 e in 2014, with the proportion of direct emissions remaining stable at above 86%. The life cycle CF in 2016 was 778.9 gCO 2 /kWh, a decrease of 20.81% compared to 2000. The positive and negative impacts of the CE from 2000 to 2016 were quantitatively analysed, and resource recycling measures will reduce the overall carbon emissions of industrial parks through the substitution of carbon-intensive energy sources. Finally, policy recommendations are proposed to reduce life cycle carbon emissions by energy replacement and embodied emissions control. The novelty of this study is the quantitative evaluation of indirect carbon emissions caused by the CE and determining the correlation between CE and carbon emissions reduction. • Highlight the indirect impact of the circular economy on carbon emissions. • Evaluate the carbon footprint (carbon emissions and reduction) of coal-fuelled power. • The life cycle carbon footprint decreased by 20.81% between 2000 and 2016 to reach 778.9 gCO 2 /kWh. • Circular economy had an overall net reduction in carbon emissions. [ABSTRACT FROM AUTHOR]

Building Information Modeling (BIM) is regarded as a potential vehicle to tremendously improve the information flow throughout the life cycle of a building. The integration of BIM and Life Cycle Assessment (LCA) has potential to reduce the time for life cycle inventory, and at the same time, substantially improve the representativeness of the LCA results for the specific building design. The latter merit is not trivial. For instance, due to time limit, most building LCA studies estimate the building materials and fuels consumed in construction phase quite roughly, which excludes the choices on a wide range of construction techniques, materials, specialties and machines, no need to mention the energy consumption in operation phase, which is usually estimated in an even bolder manner. The roughness of the LCA practice undermines its credibility and hinders its application as a decision supporting tool for low carbon design. Currently, China's Architecture, Engineering and Construction (AEC) sector is undergoing a smart transformation, steered by the increased use of BIM. This paper presents a BIM-enabled LCA method and illustrates how the method can be used to facilitate the low carbon design under the circumstance of the smart AEC transition in China. A case study on carbon footprint accounting for a residential building is conducted. In this study, various software tools and data sources are combined to enhance the data flow and interoperability between BIM models and LCA models. BIM tools are used to create the BIM model, calculate the inputs (materials, construction machines, energies, water and so on) of on-site construction process and simulate the energy consumption of building operation. The eBalance, a China's local LCA software tool is applied to build the LCA model. The Chinese Life Cycle Database is used as the main data source (72.73%) to calculate the carbon footprint of the given building while the Ecoinvent database and European Life Cycle Database act as supplementary. The results show that the carbon footprint of the building is 2993 kg CO 2 eq/m 2 . The operation phase contributes to 69% of the total greenhouse gas (GHG) emission, while the building material production contributes to 24%. Concrete is the most used building material, which accounts for 82% of mass but contributes to only 44% of the material related GHG emission. Although steel and aluminum account for only 2.6% and 1.4% of mass, they contribute to 28% and 17% GHG emission, respectively. Through BIM-enable LCA modeling, the potential life cycle environmental performance of the buildings can be assessed in detail. This makes the LCA not only more accessible but also more credible for the AEC professionals to use it as a guide for the low carbon design of buildings. [ABSTRACT FROM AUTHOR]

As one of the largest energy consumers, the transport sector generated direct and indirect emissions which significantly affect the environment, accounting for approximately one-third of the total carbon emissions. While the major impacts are from transport energy use and emissions, very few studies attempted to examine the impacts from transport infrastructure, especially at a city or country level. This paper, taking Shenzhen in China (a fast developing megacity) as the case study, is specially designed to quantify the carbon footprint of the urban roads by using streamlined life cycle assessment method. For given years (ranged from 2004 to 2013), various activities of urban roads (e.g. newly planned road construction, maintenance of road in use, and road renovation and demolition) have been examined in this study. The results show that the total carbon footprint from urban roads in Shenzhen was 260 (±20) thousand tons CO 2 e in 2013. The major contributor was the materials use (embodied impact) from newly constructed roads, which accounts for 52.3% of the total carbon footprint, followed by the maintenance stage (24.3%). The eco-design process of road construction plays a vital role in achieving the effective carbon footprint reduction. These findings help to better understand the carbon footprint from urban roads in megacities, and provide useful inputs for policy making process in terms of identifying carbon reduction opportunities for the transport sector. In addition, the methodologies are useful for the quantification of carbon footprint in other cities of China and beyond. [ABSTRACT FROM AUTHOR]

China's power industry contributes around 40% CO 2 emissions to the national total. The substitution of wind power for coal-fired power is crucial to the realization of CO 2 emission reduction target in China. By deploying the Life Cycle Assessment (LCA) method, this paper identifies that the carbon footprints of a representative coal fired plant and a wind farm in China are 810.35 g/kWh and 12.51 g/kWh respectively. Built on these results, the substitution capacities of wind power for coal-fired power to realize the CO 2 emission reduction target in 2020 and 2030 are discussed. It is concluded that China's wind power needs to develop faster than the goal set in the 12th Five Year Renewable Energy Development Plan for achieving the target of 45% emission reduction in 2020. Moreover, the feasibility of the substitution of wind power for coal-fired power is analyzed. It is argued that whilst China has great potential to realize such substitution given its rich wind resources, the full realization of the substitution requires some radical reforms in the power sector in the country. [ABSTRACT FROM AUTHOR]

Governments worldwide are attempting to reduce energy consumption and environmental pollution by confronting environmental problems and adopting more energy-efficient products. However, because of the rebound effect, energy-saving targets cannot always be fully achieved, and sometimes greater energy consumption is generated. Research on the rebound effect from the perspective of industrial ecology considers not only direct energy consumption but also its life cycle negative impacts on the environment with China’s rapid economic development and simultaneously improving quality of life, the ownership of room air conditioners (RACs) has increased more than three hundred times, and air conditioners’ energy consumption has increased one thousand times over the last twenty years. The Air Conditioner Energy Efficiency Standard is one of the most important measures in China for reducing the amount of energy consumed by RACs. This paper introduces a life cycle based method to estimate the rebound effect of Chinese RACs consumption. This model provides a product’s life-cycle view to assess the rebound effect, considering the contribution of both producer and consumer. Based on the established life cycle rebound effect model, we compared urban household RAC consumption behaviour before and after the launch of the Air Conditioner Energy Efficiency Standard. A rebound effect in RAC consumption was found that there was a longer daily usage period in the household as air conditioner efficiency levels improved. The life cycle rebound effect of household air-conditioner consumption was calculated to be 67%. The main conclusion obtained from this study is that policies and regulations should consider the rebound effect when encouraging households to alter their energy consumption patterns. [ABSTRACT FROM AUTHOR]

The reserves and exploitable capacity of the wind power resource in China are both ranked first in the world and could be developed to strengthen China’s energy security and mitigate global warming. Carbon footprint accounting of wind farms is vital for large-scale wind energy exploitation. This paper establishes a systematic accounting framework with life cycle assessment (LCA) and input–output analysis (IOA) for the overall carbon footprint of the life cycle of a typical wind farm. Carbon emissions from the construction, operation, and dismantling phases are considered in the LCA of the wind farm. Then, each expense of the wind farm is treated as a change in exogenous demand for the output of the corresponding economic sectors according to the IOA. In addition, the virtual carbon footprint from peak regulation triggered by the on-grid fluctuation of wind power is incorporated. The results show the total carbon footprint of the studied wind farm is 1.45 × 10 4 tCO 2 over the 21-year lifetime. The construction phase accounts for the largest fraction (76.74%), followed by the operation phase (15.32%) and dismantling phase (7.94%). According to the IOA, the indirect carbon footprint of the wind farm is greater than the direct footprint. The “Smelting and Pressing of Metals” sector that produces the steel and copper used to manufacture the wind turbines dominates the carbon footprint. The virtual carbon footprint of coal-fired power for wind power peak regulation is estimated to be 2.08 × 10 3 tCO 2 , which is close to that of the operation phase. [ABSTRACT FROM AUTHOR]

Abstract: Carbon footprint has become a term often used by the media in recent days. The human carbon footprint is professed to be a very serious global threat and every nation is looking at the possible options to reduce it since its consequences are alarming. A carbon footprint is a measure of the impact of human activities on earth and in particular on the environment; more specifically it relates to climate change and to the total amount of greenhouse gases produced, measured in units of carbon dioxide emitted. Effort of individuals in minimizing the carbon footprint is vital to save our planet. This article reports a study of the carbon footprint of various types of shopping bags (plastic, paper, non-woven and woven) using life cycle impact assessment (LCIA) technique in two stages. The first stage (baseline study), comprised the study of the impact of different types of shopping bags in the manufacturing phase, without considering their usage and disposal phases (cradle to gate stage). The LCIA was accomplished by the IPCC 2007 method, developed by the Inter Panel on Climate Change in SIMAPRO 7.2. The GWP (Global Warming Potential) values calculated by the IPCC 2007 method for 100 years were considered as a directive to compare the carbon footprint made by the different types of shopping bags under consideration. The next stage was the study of the carbon footprint of these bags including their usage and disposal phases (cradle to grave stage) and the results derived were compared with the results derived from the baseline study, which is the major focus of this research work. The values for usage and end-of-life phases were obtained from the survey questionnaire performed amongst different user groups of shopping bags in China, Hong Kong and India. The results show that the impact of different types of shopping bags in terms of their carbon footprint potential is very high if no usage and disposal options were provided. When the carbon footprint values from different disposal options were compared, the carbon footprint values were lower in the case where a higher percentage of reuse is preferred to recycling and disposing to landfill. The results indicate that a higher percentage of reuse could significantly scale down the carbon footprint. Once the shopping bags reached the point where they can no longer be reused, they must be forwarded to recycling options, rather than being disposed to landfill. At this juncture, consumer’s perceptions and behaviours in connection with the respective government’s policies in promoting & facilitating recycling systems could be critical in reducing the carbon footprint of various shopping bags. [Copyright &y& Elsevier]

Many countries like China are in a dilemma between economic growth and environmental deterioration (e.g., smog weather). Simultaneously, a growing people concern the product's environmental performance along with their improving environment awareness. This paper focuses on the impacts of carbon footprint and low-carbon preference on the production decision of emission-dependent firms in the cap-and-trade system. The cap-and-trade system uses the total “cap” to attain environmental goals and allows “trade” to achieve the effective scheduling through market regulation. Under this mechanism, through analyzing the influence of carbon footprint and low-carbon preference on the market supply and demand, we build a production optimization model and develop the optimal decisions. Several interesting management insights on environmental preference and policy are concluded. [ABSTRACT FROM AUTHOR]

Fossil fuels are major feedstock for industrial processes in the word. However, processing fossil fuels emits a large amount of CO 2 giving a serious environmental impact. Conventional analysis of this impact is to quantify Global Warming Potential by using CO 2 equivalent, but not on quantitatively energetic and economic metrics. This cannot measure a real cost of ecological goods and services, e.g. carbon sequestration, biogeochemical cycles, mineral and fossil resources. To address this issue, this paper introduces energetic and economic penalties. They are inspired by circulation of CO 2 between industrial and ecological systems and defined as the additional energetic and economic costs for closing the CO 2 loop by using ecological goods and services. These additional costs are considered as penalties. The carbon footprint and life cycle exergy/cost rate are applied to model the penalties. These models consider regional condition, for they include some regional ecological factors. Coal-to-olefins projects in different regions of China are used as case studies. Their energetic and economic penalties are calculated. Results show that olefins productions in Gansu, Ningxia, and Sinkiang suffer from the highest penalties. For economic penalties, they are higher than 2400 RMB/t olefins. Productions in Inner Mongolia and Shanxi have the penalties in middle range, 1235 RMB/t olefins and 1656 RMB/t olefins. Productions in other regions pay much lower penalties, around 1000 RMB/t olefins. [ABSTRACT FROM AUTHOR]

• Impact-based water footprint of rolled steel production is first performed. • Fossil energy footprint and carbon footprint are evaluated by using LCA. • Maritime transport, iron power and direct emissions are major contributors. • Adjustment of industrial structure is essential for carbon mitigation of steel industry. The Iron and Steel Industry (ISI) is a difficult-to-mitigate sector that has considerable contributions to energy consumption, water pollution, and CO 2 emissions. Despite broad interest in energy consumption and CO 2 emissions generated by steel production, there are few impact-oriented Water Footprint (WF) assessments of steel production. This study evaluates the water, carbon and fossil energy footprints generated from rolled steel production on the basis of life cycle assessment. Key contributors attributing to those environmental impacts are also identified so as to explore their potential mitigation. Using the Monte Carlo model, an uncertainty analysis is conducted with the aim of providing reliable results for decision-making. Results show that the impact per ton China's rolled steel production has on global warming, human health, ecosystem quality, and resources is 4.40 × 103 kg CO 2 eq (GSD2 = 1.24), 4.15 × 10-3 Disability Adjusted of Life Years (DALY) (GSD2 = 1.31), 7.08 × 10-5 Species·yr (GSD2 = 2.04), and 4.39 × 104 MJ (GSD2 = 1.28), respectively. Global warming and freshwater ecotoxicity is the dominant contributor to the damage impact on human health and ecosystem quality, respectively. Results also show that the transport (freight ship) of raw materials and the production of iron powder are the two main contributors to the overall impact on the environment that rolled steel production has. Several policy recommendations are proposed in this paper, which focus on adjusting the steel industry's industrial structure, promoting the national-level carbon emissions trading in the ISI, promoting international cooperation, and improving public awareness of green and low-carbon development. Such policy recommendations provide decision-makers with valuable insights, which thus allow them to prepare the appropriate mitigation policies. [ABSTRACT FROM AUTHOR]

China shares 13.15% and 69.23% of the global magnesite reserves and production respectively. Magnesia is an important connecting link between magnesite and refractory. It is approximately over 80% of magnesite industry that the carbon emitted from magnesia production is directly caused by carbonate decomposition and fossil fuel combustion. Therefore, the study of carbon footprint in magnesia production is valuable for carbon reduction. However, the researches on carbon reduction in magnesia production are rare. In this paper, the carbon footprint method is employed to quantitatively investigate the carbon reduction capacity in magnesia production under the influence of product structure, production process and equipment, and energy source structure. The results show that, for different magnesia, the carbon footprints are 3.937–4.804 kgCO 2 -eq/kg of fused magnesia, 2.151–3.064 kgCO 2 -eq/kg of sinter magnesia and 1.440–2.221 kgCO 2 -eq/kg of light calcinated magnesia at present, respectively. Moreover, for improvement of production process and equipment, the carbon footprint of flash calcinator is 0.489–1.218 kgCO 2 -eq/kg lower than that of reverberatory furnace for light calcinated magnesia. Similarly, the application of a high-power electricity arc furnace decreases the carbon footprint by 0.763–3.506 kgCO 2 -eq/kg of fused magnesia. Furthermore, for energy source replacement, the introduction of nuclear power has a carbon reduction capacity of 0.334–2.058 kgCO 2 -eq/kg-magnesia compared with coal-fired power. It will be 0.473–3.172 kgCO 2 -eq/kg-magnesia when hydrogen is employed as fuel compared with natural gas and producer gas. Finally, the combination of nuclear power, hydrogen and the carbon capture system will further pull the carbon footprint down to 0.244–0.767 kgCO 2 -eq/kg-magnesia. [ABSTRACT FROM AUTHOR]

Abstract: To respond to the call of greenhouse gas emissions mitigation, an efficient carbon accounting framework should be proposed. Traditional narrowly defined estimation protocols that consider the direct emissions from native energy consumption may generally lead to underestimates of the carbon emissions derived from providing products and services. To comprehensively evaluate the supply-chain carbon performance in all economic sectors of China, the Economic Input–Output Life Cycle Assessment (EIO-LCA) based carbon footprint accounting framework should be employed. Because carbon emissions also occur in non-energy production processes, carbon emissions from the non-energy industrial process should also be incorporated into the accounting framework. This paper assessed 3 scopes of carbon emissions of Chinese economic sectors, including (1) direct emissions from energy consumption, and the industrial process, (2) emissions from purchased energy, (3) supply chain emissions combining both fuel combustion and industrial processes. The results shown that there is a huge underestimation of the carbon emission from various sectors using traditional carbon protocols compared with the tier 3 supply-chain CO2 emission. The emissions from industrial processes also constitute a large proportion, which cannot be ignored. In addition, we find that embodied CO2 emissions in exports concentrated on primary energy intensive sectors, indicating the importance of restructuring of export goods and services. It is proved that the three tier model provides a tool for decision makers to identify the national high carbon emission sectors and make effective carbon mitigation strategies. [Copyright &y& Elsevier]

Since the concept of low-carbon has been incorporated in all aspects, low-carbon tourism, as one of the vital branches of low-carbon economy, has grasped much attention from researchers. Under the current trends, the actual emissions of greenhouse gas will be doubled the planned target in the future, which are obviously overlooked by the tourism industry. In terms of carbon footprint measurement, this paper proposes a multi-dimensional model with four low-carbon sub-systems including economy, environment, control and management and selects Xingwen Global Geopark as the sample in the scenario-based planning. Inspired by the idea of responsible tourism, this paper applies dynamic model in measuring carbon footprint, so as to provide future policy implications for geoparks. Through the scenario-based prediction of carbon footprint in Xingwen Global Geopark, we found it has experienced a constant promotion in low-carbon development with increasing carbon footprint but decreasing carbon intensity; the booming of tourists may bring worsen carbon footprint, slow-paced increase of tourists but poorer low-carbonization will possibly result in high carbon intensity; the current path is not the best and not conducive for middle and later period before 2030; the results of scenario analysis indicate that the win-win development can only be achieved through the low-carbon construction of scenic spots. Image 101797 • A conceptual logical DPSIRM framework is developed for low-carbon tourism system. • Traditional static measurement for tourism-related carbon footprint is transformed into dynamic measurement. • Carbon footprint of key elements in tourism is dynamically illustrated under different scenarios. • Responsible tourism is introduced to enrich the perspective of scenario planning analysis. [ABSTRACT FROM AUTHOR]

Abstract: Characterizing the carbon footprint (CF) of agricultural production offers key information for pursuing low carbon agriculture and food consumption. While China has long strived for increasing food production capacity for its large and still growing population, the high emissions cost, especially from the over use of agro-chemicals, has been widely debated for the last decade. However, the CF of China''s crop production has not yet been assessed. This paper reports a basic estimate of CF of crop production using national statistical data available for the period of 1993–2007. The dataset includes the amount of individual agricultural inputs (fertilizer, pesticide, diesel, plastic film, etc.), cultivation area and total of production whole crops. Using the emission factors estimated for China''s agricultural features and available abroad, the mean overall CF of China''s crop production was estimated to be 0.78±0.08tCEha−1 yr−1 and 0.11±0.01tCEt−1 yr−1, for land use and bulk production respectively. For the duration the data covered, the carbon intensity under cultivation land use was seen to increase since 1993. Among the total, fertilizer induced emissions exerted the largest contribution of ∼60%, being 0.45±0.04tCE per ha and 0.07±0.01tCE per ton of production, on average. Compared to the UK, the estimated overall CF of China''s crop production was higher in terms of cultivation land use. While there was a significant positive correlation of carbon intensity with total production, carbon efficiency was shown in a decreasing trend during 2003-2007. Therefore, low carbon agriculture should be pursued, and the priority should be given to reducing fertilizer application in agriculture of China. However, for developing best management practices for climate change mitigation in crop production of China, further studies of crop and regional specific CFs and the variation with climate conditions and agricultural managements are needed. [Copyright &y& Elsevier]

The mismatching of grain production and consumption in space causes grain virtual water flow. Previous studies focused on the important role of virtual water trade in regional food security and its impact on water resource consumption, while this study focuses on the impact of virtual water flow on the environment. In this paper, two indexes of gray water footprint and carbon footprint were selected by footprint evaluation method to study the influence of virtual water flow on regional environment. The results show that the scale of grain virtual water flow gradually expanded, and the amount of virtual water flow increased from 67.14 Gm³ to 129.87 Gm³ from 1997 to 2014. The gray water footprint at a national scale showed a fluctuating trend, with obvious differences in temporal and spatial distribution. In addition, the total carbon footprint at the national scale increased from 290.2 Mton in 1997–430.4 Mton in 2014, basically showing a continuous increase trend. Provinces with larger gray water footprints are basically converted into import areas, and the total national gray water footprint reduced 64.74 Gm3. Meanwhile, the carbon footprint of the grain export region and import region changed significantly. Among the export areas, such as the Northeast region and the Huang-Huai-Hai region, the carbon footprint had an obvious downward trend. On the other hand, the carbon footprint of the import region in the south due to increasing of grain production to meet their own needs showed an increasing trend. Although virtual water flow reduced the gray water footprint and carbon footprint nationally, it increased the local environmental pressure on the export area. This study would be helpful in forming better water management policy and alleviating regional environment pressure. • Virtual water flow shows an environmentally friendly model in the overall situation. • Virtual water flow increases the gray water and carbon footprint in the export area. • The environmental impact rate of the export area is higher than that of import area. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions related to food production in selected countries around the world in 2000, 2007, and 2014 were analyzed in this paper. In recent decades, many studies have suggested that greenhouse gas emissions mostly caused by agricultural production should be reduced. However, a low-carbon agricultural sector often involves a reduction in inputs, which may result in smaller production volumes. Nevertheless, the overarching goal should be to maintain food production at a sufficient level to meet the population's food requirements. Food production is particularly important in the context of the forecasted growth of the world population. In this situation, greenhouse gas emissions per product unit should be regarded as a key indicator that reflects the environmental sustainability level of production processes. Defined as such, environmental sustainability was examined across the entire food production system—referred to as agribusiness. This study calculated the emissions of major greenhouse gases related to food production and compared them to the GDP of agribusiness. The average ratio of the agribusiness carbon footprint to GDP in countries examined was nearly 2 kg of CO 2 equivalent/USD in 2000. This value kept decreasing during the study period, reaching 1.21 in 2014. A decrease in the ratio was recorded despite an increase in agribusiness greenhouse gas emissions, which validated the research hypothesis that an increase in greenhouse gas emissions from agribusiness does not necessarily reflect a decline in the environmental performance of agribusiness production. This is especially true for China and Brazil, whose greenhouse gas emissions related to food production increased considerably in the years examined in this study along with a clear decline in emission levels per unit of agribusiness GDP. This study is innovative, because the literature does not provide any similar calculations for the food production subsystem, especially regarding emission levels per production unit. This approach required the authors to integrate the calculation methods used in agribusiness production with those applicable to agribusiness greenhouse gas emissions. Thus, this study relied on consistent methods developed by the authors to calculate these values. The research adds to existing literature by calculating the carbon footprint for the entire food production system, and it argues that better environmental performance of agribusiness production can be achieved despite higher greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Ambitious scenarios of carbon emission redistribution for mitigating climate change in line with the Paris Agreement and reaching the sustainable development goal of eradicating poverty have been proposed recently. They imply a strong reduction in carbon footprint inequality by 2030 that effectively halves the Gini coefficient to about 0.25. This paper examines feasibility of these scenarios by analyzing the historical evolution of both weighted international inequality in CO 2 emissions attributed territorially and global inequality in carbon footprints attributed to end consumers. For the latter, a new dataset is constructed that is more comprehensive than existing ones, and footprints are found to be more unequal than territorial emissions. In both cases, we find a decreasing trend in global inequality, partially attributed to the move of China from the lower to the middle part of the distributio. Still, realization of the redistributive scenarios would require an unprecedented reduction in global inequality far below historical levels. Moreover, the territorial emissions data, available for more recent years up to 2017, show a saturation of the decreasing Gini coefficient at a level of 0.5. This observation confirms an earlier prediction based on maximal entropy reasoning that the Lorenz curve converges to the exponential distribution. This saturation further undermines feasibility of the redistributive scenarios, which are also hindered by structural tendencies that reinforce carbon footprint inequality under global capitalism. One way out of this conundrum is a fast decarbonization of the global energy supply in order to decrease global carbon emissions without relying crucially on carbon inequality reduction. [ABSTRACT FROM AUTHOR]

With increasing water shortages partly due to increasing demands, water has become a globally relevant issue especially in arid and semi-arid regions. Water-saving irrigation technologies provide new ways for improving the efficiency of water use for agricultural production. Although efficient irrigation management could lead to water savings and increased yields, the water consumption and greenhouse gas emissions during the construction of irrigation projects also puts pressure on environmental health. However, little research has considered the environmental impact of the construction process and materials. To fill this gap, the water footprint (WF) and carbon footprint (CF) of irrigation projects were calculated using life cycle assessment (LCA) methods. The results for sixty typical irrigation projects in northern China showed that the WF accounted for only 0.2–1.5% of the total agricultural WF and 2.3–8.8% of the water saved. When the WF to construct modern irrigation systems is not considered, the water-saving effects of these systems are generally overestimated by 13%. The CF for irrigation projects was 42.0% of all agricultural activities. Due to the difficulty to obtain detailed information for irrigation projects, this paper established the relationship between financial investment or area and CF for three kinds of irrigation projects. It provided a simple quantitative method for assessing its environmental impacts. By comparing environmental impacts and production benefits under different scenarios, using drip irrigation over the long-term could increase crop yield and reduce water footprint, but carbon footprint was increased at the same time. This study suggests that it is necessary to assess the environmental impacts of irrigation construction projects from a life cycle perspective rather focusing only on yield increases and reductions in irrigation amounts. Image 1 • The environmental impact of irrigation projects was quantitatively evaluated first time. • The benefits of efficient water-saving irrigation projects are overestimated. • The carbon footprint is positively correlated with its investment and area. • Long-term drip irrigation could increase yield while reducing environmental impact. [ABSTRACT FROM AUTHOR]