Average Global Warming Potential Research Articles

Environmental sustainability issues in the food–energy–water nexus: Breakfast cereals and snacks

Understanding environmental impacts of complete food supply chains is important for the food industry to help devise strategies for reducing the impacts of current and future products. Breakfast cereals are one of the most important foods consumed in many countries, but their environmental impacts are currently unknown. Therefore, this study explores the environmental sustainability issues in the food–energy–water nexus by considering breakfast cereals manufactured by one of the world’s largest producers, Kellogg Europe. A life cycle assessment has been carried out for these purposes with the aim of helping the Company to integrate environmental sustainability considerations into the design of their products and packaging. The results indicate that the average global warming potential (GWP) of Kellogg’s breakfast cereals is 2.64 kg CO2 eq. per kg of product. The main GWP hotspots are the ingredients (48%) and energy used in the manufacturing process (23%); packaging and transport contribute 15% each. Rice is the single largest contributor to the GWP of the ingredients (38%). The manufacturing stage is the main contributor of primary energy demand (34%), while the ingredients are responsible for more than 90% of the water footprint. The ingredients are also the main contributors to most other environmental impacts, including land use (97%), depletion of elements (61%), eutrophication (71%), human toxicity (54%) and photochemical smog (50%). The impacts from packaging are high for freshwater and marine toxicity. The contribution of transport is significant for depletion of elements and fossil resources (23%), acidification (32%), ozone depletion (28%) and photochemical smog (24%). Improvement opportunities explored in the paper include better agricultural practices, recipe modifications, improved energy efficiency of manufacturing processes and use of alternative packaging. Impacts from consumption are also discussed.

The hourly life cycle carbon footprint of electricity generation in Belgium, bringing a temporal resolution in life cycle assessment

In the booming research on the environmental footprint of, for example, electrical vehicles, heat pumps and other (smart) electricity consuming appliances, there is a clear need to know the hourly CO2 content of one kWh of electricity. Since the CO2 footprint of electricity can vary every hour; the footprint of for example an electric vehicle is influenced by the time when the vehicle is charged. With the availability of the hourly CO2 content of one kWh, a decision support tool is provided to fully exploit the advantages of a future smart grid. In this paper, the GWP (Global Warming Potential) per kWh for each hour of the year is calculated for Belgium using a Life Cycle Assessment (LCA) approach. This enables evaluating the influence of the electricity demand on the greenhouse gas emissions. Because of the LCA approach, the CO2 equivalent content does not only reflect activities related to the production of the electricity within a power plant, but includes carbon emissions related to the building of the infrastructure and the fuel supply chain. The considered feedstocks are nuclear combustible, oil, coal, natural gas, biowaste, blast furnace gas, and wood. Furthermore, renewable electricity production technologies like photovoltaic cells, hydro installations and wind turbines are covered by the research. The production of the wind turbines and solar panels is more carbon intensive (expressed per generated kWh of electricity) than the production of other conventional power plants, due to the lower electricity output. The overall average GWP per kWh is 0.184kg CO2eq/kWh. Throughout the 2011 this value ranges from a minimum of 0.102kg CO2eq/kWh to a maximum of 0.262kg CO2eq/kWh depending on the timing.

Calculation of domestic flight-caused global warming potential from aircraft emissions in Turkish airports

In this study, global warming potential (GWP) is calculated for aircrafts used in Turkish airports. The basic idea of this study is to investigate both emissions and their GWP values. This study is conducted in three steps, namely: 1) finding busiest airports in Turkey; 2) specifying the most used aircraft types and its engines; and 3) calculation of domestic flight-caused GWP value for both the total number of aircraft and per-passenger evaluation. In this regard, the Intergovernmental Panel on Climate Change (IPCC) 2007 GWP 100a methodology is utilised along with the method of the life cycle assessment. While the total average GWP value is 1,629 kg carbon dioxide equivalent (CO 2 e) per landing and takeoff (LTO), the total domestic flight-caused GWP value was calculated as 257,305 tons of CO 2 e per year in 2002 and 998,118 tons of CO 2 e per year in 2012. While, the last two years have had an average value of 12–13 kg CO 2 e per passenger for one airport, the GWP values per passenger have averaged 15.35 kg CO 2 e per passenger, per airport over these years.

The environmental impacts of lowland paddy rice: A case study comparison between rainfed and irrigated rice in Thailand

North-eastern Thailand is an essential production area for high-quality fragrant rice for domestic use and export. While rainfed conditions largely prevail, plans to extend irrigation are drafted. This article compares paddy rice production under irrigation and rainfed conditions. Techno-economic performances were analysed jointly with environmental impacts, based upon life cycle analysis, and energy and water use analyses. Data were collected in 2010 from 45 diverse rice cropping systems in the Lam Sieo Yai Basin, according to three systems, namely wet-season rain-fed (Rw), wet-season irrigation (Iw), and dry-season irrigation (Id) systems. Wide-ranging performances and impacts were observed, while cropping practices were relatively homogeneous. Differentiation of systems originated mostly from differences in yield, which were largely impacted by water supply. The results highlight the low performances and high impacts of Id systems. They require mostly blue water, while the two other systems rely primarily on green water. Id systems also require more energy and labour, due to increased water management needs. The productivity of most production factors was higher in Rw and Iw systems. Emissions proved relatively similar across systems, with the exception of CH4, which was markedly lower in Rw systems due to specific water and organic residue management. Id systems systematically emitted more nitrates, phosphates, and pesticides. Rw systems showed the lowest environmental impacts per ha and per kg of paddy rice produced. The average Global Warming Potential was 2.97 kg CO2-eq per kg rice in Rw systems, 4.87 in Iw systems, and 5.55 in Id systems. This article further discusses the results in view of contrasting perspectives, including societal objectives, farmer income and environmental integrity, and possible irrigation development in north-eastern Thailand.

On the study of energy use and GHG (greenhouse gas) emissions in greenhouse cucumber production in Yazd province

In recent years, besides the energy issues, the GHG (greenhouse gas) emission, which is the most important cause of global warming, has received high attention. In order to have sustainable development, it is necessary to manage energy usage and GHG emissions in all production processes. This study aimed to evaluate the energy consumption and GHG emissions of cucumber production in selected greenhouses in Yazd province of Iran. The total energy input was found to be 1284 GJ ha−1 where the output energy was 125 GJ ha−1. Energy use efficiency and productivity were 0.10 and 0.12 kg MJ−1, respectively. Diesel fuel and electricity had the biggest contributions in the total energy input. Regression results showed that labor, diesel fuel, manure, electricity and chemicals had significant impact on yield. The amount of GHG emissions was calculated as 82,724 kg CO2eq ha−1 where diesel fuel had the highest emission (61%), followed by electricity (19%) and manure (14%). GWP (Global warming potential) was 0.53 kg CO2eq ha−1(kg Output)−1. The average GWP per MJ output was 0.66 kg CO2eq ha−1(MJ Output)−1, where the highest value belonged to smaller greenhouses. The results of energy analysis, GHG and GWP indicators based on different greenhouse sizes implied better performance of larger greenhouses.

Environmental Impact Assessment – methodology with special emphasis on European pork production

One of the most discussed topics worldwide is climate change, upon which livestock production is known to have a great environmental impact. There are different methods to measure these environmental impacts, some of which are mentioned in this review. It especially focuses on the method of Life Cycle Assessment (LCA), because it is widely used, of high relevance and good quality. This review highlights a sample of the few published European LCA studies on pork production. These assessments result in an average global warming potential of 3.6 kg CO(2)- eq per kg pork, ranging from 2.6 to 6.3 kg CO(2)- eq per kg pork. Additionally, it illustrates the main limitations of the methodology itself (e.g. data intensiveness, different allocation techniques) and its application in pork production (e.g. limited data availability, use of multiple functional units, varying system boundaries). The missing comparability of various studies arising from a vague standard still represents the main problem in LCA. Therefore, a new standardisation and the development of a more exhaustive database would generate a future trend.

Simulation of global warming potential (GWP) from rice fields in the Tai-Lake region, China by coupling 1:50,000 soil database with DNDC model

Quantifying greenhouse gas (GHG) emissions from wetland ecosystems is a relatively new issue in global climate change studies. China has approximately 22% of the world's rice paddies and 38% of the world's rice production, which are crucial to accurately estimate the global warming potential (GWP) at regional scale. This paper reports an application of a biogeochemical model (DeNitrification and DeComposition or DNDC) for quantifying GWP from rice fields in the Tai-Lake region of China. For this application, DNDC is linked to a 1:50,000 soil database, which was derived from 1107 paddy soil profiles compiled during the Second National Soil Survey of China in the 1980–1990s. The simulated results show that the 2.34 Mha of paddy soil cultivated in rice–wheat rotation in the Tai-Lake region emitted about −1.48 Tg C, 0.84 Tg N and 5.67 Tg C as CO 2, N 2O, and CH 4 respectively, with a cumulative GWP of 565 Tg CO 2 equivalent from 1982 to 2000. As for soil subgroups, the highest GWP (26,900 kg CO 2 equivalent ha −1 yr −1) was linked to gleyed paddy soils accounting for about 4.4% of the total area of paddy soils. The lowest GWP (5370 kg CO 2 equivalent ha −1 yr −1) was associated with submergenic paddy soils accounting for about 0.32% of the total area of paddy soils. The most common soil in the area was hydromorphic paddy soils, which accounted for about 53% of the total area of paddy soils with a GWP of 12,300 kg CO 2 equivalent ha −1 yr −1. On a regional basis, the annual averaged GWP in the polder, Tai-Lake plain, and alluvial plain soil regions was distinctly higher than that in the low mountainous and Hilly soil regions. As for administrative areas, the average annual GWP of counties in Shanghai city was high. Conversely, the average annual GWP of counties in Jiangsu province was low. The high variability in soil properties throughout the Tai-Lake region is important and affects the net greenhouse gas emissions. Therefore, the use of detailed soil data sets with high-resolution digital soil maps is essential to improve the accuracy of GWP estimates with process-based models at regional and national scales.

Introducing greenhouse gas mitigation as a development objective in rice-based agriculture: I. Generation of technical coefficients

This study presents a modeling tool to assess emission of greenhouse gases (GHG) from the agricultural sector as affected by land-use and residue utilization options. The overall purpose of this tool is twofold: (i) a spreadsheet model for comprehensive compilation of the direct and indirect emissions from land management, residue-burning and fossil fuel consumption through on-farm and off-farm operations and (ii) a decision support tool to explore economically viable mitigation options through detailed cost–benefit analysis of different technological options. We developed TechnoGAS (technical coefficient generator for mitigation technologies of greenhouse gas emissions from agricultural sectors), which integrates analytical and expert knowledge with regional databases on bio-physical, agronomic and socio-economic features to establish input–output relationships (‘Technical Coefficients’) related to GHG emissions in agriculture. The approach includes emissions of methane (CH 4) from rice fields, rice straw burning and cattle; carbon dioxide (CO 2) from fossil fuel and soil organic carbon decline as well as nitrous oxide (N 2O) from soil, rice straw burning and fertilizer use. To illustrate the approach of the spreadsheet model for comprehensive compilation of emissions, we applied TechnoGAS for an entire rice–wheat cropping cycle in the state of Haryana in northern India as a case study. Twenty technologies of rice production, which can be adopted by farmers, are analysed for their operation-specific emissions including their global warming potential (GWP). The technologies differ in terms of water regime, residue management/utilization, soil management and additives, which represent different mitigation options for GHG emissions. With the current farmers’ practice in various districts in Haryana, soil-borne emissions are the major source of GHG contributing 53% of the average GWP (3288 kg CO 2 equivalent ha −1) in rice followed by burning of rice straw (13% of the GWP). Cattle, farm operations, off-farm and inorganic fertilizer contributes 12%, 10%, 10% and 2% of the GWP, respectively. Emissions from wheat are relatively low (1204 kg CO 2 equivalent ha −1) as there is no CH 4 emission and wheat straw is not burnt. Different mitigation technologies show pronounced effects on the GWP of the rice crop and varied between 1715 kg CO 2 equivalent ha −1 with continuous flooding, urea and rice straw used for building materials and 10,020 kg CO 2 equivalent ha −1 with continuous flooding, and application of nutrients through organic manure. Compared to current farmers’ practice, 13 technologies are found to have the potential to reduce the GWP by 8–51%, but they also reduce the net income of farmers. Upscaling of the estimates to the entire state of Haryana shows that the GWP with the current farmers’ practice in rice is 2617 Gg CO 2 equivalent. Modification of water management from continuous flooding to alternate flooding or application of urea alone instead of urea plus FYM will reduce the GWP by 15% and 29%, respectively, while feeding of rice straw to cattle and supplying N through urea will reduce it by 41% compared to the current practice of burning rice straw and use of FYM. The study shows that the TechnoGAS tool can be used for estimating GHG emission from various land-use types and for identifying promising mitigation options. A detailed cost/benefit analysis is supplied by Wassmann and Pathak [Wassmann, R., Pathak, H., this volume. Introducing greenhouse gas mitigation as a development objective in rice-based agriculture: II. Cost–benefit assessment for different technologies, regions and scales.].

An assessment of the energy inputs and greenhouse gas emissions in sugar beet ( Beta vulgaris) production in the UK

Reducing the energy derived from fossil fuels within agricultural systems has important implications for decreasing atmospheric emissions of greenhouse gases, thus assisting the arrest of global warming. The identification of crop production methods that maximise energy efficiency and minimise greenhouse gas emissions is vital. Sugar beet is grown in a variety of locations and under a variety of agronomic conditions within the UK. This study identified thirteen production scenarios, representative of over 90% of the UK beet crop, which included five soil types, nine fertiliser regimes and nine crop protection strategies. The fossil energy input, the overall energy efficiency and the global warming potential (GWP) of each production scenario was assessed. This study did not consider the processing of the beet to extract sugar. The overall energy input of the UK beet crop ranges between 15.72 and 25.94 GJ/ha. It produces between 7.3 and 15.0 times as much energy in dry matter at the sugar factory gate as consumed in its production, with an average ratio of 9.7. It has an average GWP of 0.024 eq. t CO 2 per tonne of clean beet harvested, equivalent to 0.0062 eq. t CO 2 per GJ output. The energy input into each scenario was dictated largely by the energy associated with crop nutrition. The smallest energy inputs per hectare were to crops grown under organic conditions or conventional crops grown on fertile soils (clay loam, silt or peat) or sand soil with broiler manure applied. Those crops with the greatest energy input were grown on sand soil that was irrigated and had mineral fertiliser applied. Although the organic scenario grown on sandy loam soil had one of the smallest energy inputs per hectare, the low yield meant that the energy input was similar per tonne of beet harvested to the conventional crops grown on sandy loam soil. The extra distance travelled by organic beet from the farm to the factory increased the energy input per tonne above that of the conventional scenarios. The GWP was smallest for the conventional crops on the fertile peat and silt soils and greatest on the irrigated sand soils and the sandy loam soils. The organic scenario had a similar GWP to the conventional scenarios on sandy loam to the farm gate, although the greater diesel requirement for transport increased the GWP overall. The GWP per GJ of output for sugar beet in England is similar to published values for wheat.

アルミニウム一次地金の輸入元を考慮した環境負荷データの比較

Primary aluminum consumes much energy in its production process-es leading a great quantity of emissions. In Japan, 99 ‰ amount of primary aluminum is currently imported from other countries. In this work, Global Warming Potential (GWP) and Acidification Potential (AP) values for primary aluminum ingot produced in Brasilia, Russia, Australia, Venezuela, U. S. A., Norway and Island have been investigated. The average GWP and AP values for Japanese import mixtures were calculated. The mini-mum GWP and AP values for primary aluminum ingot produced with best available tech-nology have also been estimated.It was found that GWP value of primary aluminum ingot produced in each country varied from 10.4 to 27.4 kg-CO2 equiv./kg, while AP value varied from 0.0172 to 0.135 kg-SO2 equiv./kg. The average GWP and AP values for Japanese import mixtures were 15.5 kg-CO2 equiv./kg and 0.0516 kg-SO2 equiv./kg, respectively. GWP value of primary alu-minum ingot could be reduced up to 6.32 kg-CO2 equiv./kg if it is produced with best available technology, and AP value could be reduced up to 0.0103 kg-SO2 equiv./kg. The environmental impact of primary aluminum ingot widely varies according to which coun-tries primary aluminum ingot was produced in and which technology was used in its pro-duction process.

Fluorocarbons and Sulfur Hexafluoride (6): a Methodology for National Emission Inventories and Scenarios Applied to The Netherlands

A six-step methodology for estimating use (Steps 1–5) and emissions (Step 6) of fluorocarbons not regulated under the Montreal Protocol and 6 has been described, to improve insight into emissions in the Netherlands. The last step is largely in line with methods applied in the annual AFEAS reports and under discussion within the IPCC, and estimates HFCs, PFCs, FICs and 6 released as the sum of (1) emission from compounds used as substitutes for ozone-depleting compounds (2) emissions due to 6's historical market and (3) emissions from other industrial processes. Emissions in the Netherlands were estimated for scenarios assuming that the Montreal protocol will be implemented. Without additional measures (reference scenario emissions of HFCs, PFCs, FICs and 6 increase from 878 (metric) tons in 1990 to 6983 tons in 2020. In 2020 emissions are estimated to be about 21 Mt CO2 equivalents, or 13% of the CO2 target for that year (i.e. stabilization at the 2000 level). Assuming maximum emission control through good housekeeping, recycling and waste destruction, emissions are 40–50% lower than in the no-control scenarios. The closed applications only scenario assumes use of these compounds to be restricted to stationary cooling and closed-foam blowing. In this scenario, emissions are 15–25% (no-control case) and 50–60% (maximum emission control case) lower than in the reference scenario. Reductions up to 90% are found in the low-GWP scenario, assuming an average Global Warming Potential of the mix of compounds used of 250 or less.