15 research outputs found
Environmental effects of coffee, tea and cocoa- data collection for a consumer guide for plant-based foods
In 2020, WWF launched a consumer guide on plant-based products targeting Swedish consumers. The development of the guide is described in a journal paper (Karlsson Potter & Röös, 2021) and the environmental impact of different plant based foods was published in a report (Karlsson Potter, Lundmark, & Röös, 2020). This report was prepared for WWF Sweden to provide scientific background information for complementing the consumer guide with information on coffee, tea and cocoa. This report includes quantitative estimations for several environmental categories (climate, land use, biodiversity and water use) of coffee (per L), tea (per L) and cocoa powder (per kg), building on the previously established methodology for the consumer guide. In addition, scenarios of consumption of coffee, tea and cocoa drink with milk/plant-based drinks and waste at household level, are presented. Tea, coffee and cacao beans have a lot in common. They are tropical perennial crops traditionally grown in the shade among other species, i.e. in agroforestry systems. Today, the production in intensive monocultures has negative impact on biodiversity. Re-introducing agroforestry practices may be part of the solution to improve biodiversity in these landscapes. Climate change will likely, due to changes in temperature, extreme weather events and increases in pests and disease, alter the areas where these crops can be grown in the future. A relatively high ratio of the global land used for coffee, tea and cocoa is certified according to sustainability standards, compared to other crops. Although research on the implications of voluntary standards on different outcomes is inconclusive, the literature supports that certifications have a role in incentivizing more sustainable farming. Coffee, tea and cocoa all contain caffeine and have a high content of bioactive compounds such as antioxidants, and they have all been associated with positive health outcomes. While there is a strong coffee culture in Sweden and coffee contributes substantially to the environmental impact of our diet, tea is a less consumed beverage. Cocoa powder is consumed as a beverage, but substantial amounts of our cocoa consumption is in the form of chocolate. Roasted ground coffee on the Swedish market had a climate impact of 4.0 kg CO2e per kg powder, while the climate impact of instant coffee powder was 11.5 kg CO2e per kg. Per litre, including the energy use for making the coffee, the total climate impact was estimated to 0.25 kg CO2e per L brewed coffee and 0.16 kg CO2e per L for instant coffee. Less green coffee beans are needed to produce the same amount of ready to drink coffee from instant coffee than from brewed coffee. Tea had a climate impact of approximately 6.3 kg CO2 e per kg dry leaves corresponding to an impact of 0.064 CO2e per L ready to drink tea. In the assessment of climate impact per cup, tea had the lowest impact with 0.013 kg CO2e, followed by black instant coffee (0.024 kg CO2e), black coffee (0.038 kg CO2e), and cocoa drink made with milk (0.33 kg CO2e). The climate impact of 1kg cocoa powder on the Swedish market was estimated to 2.8 kg CO2e. Adding milk to coffee or tea increases the climate impact substantially. The literature describes a high proportion of the total climate impact of coffee from the consumer stage due to the electricity used by the coffee machine. However, with the Nordic low-carbon energy mix, the brewing and heating of water and milk contributes to only a minor part of the climate impact of coffee. As in previous research, coffee also had a higher land use, water use and biodiversity impact than tea per L beverage. Another factor of interest at the consumer stage is the waste of prepared coffee. Waste of prepared coffee contributes to climate impact through the additional production costs and electricity for preparation, even though the latter was small in our calculations. The waste of coffee and tea at Summary household level is extensive and measures to reduce the amount of wasted coffee and tea could reduce the environmental impact of Swedish hot drink consumption. For the final evaluation of coffee and tea for the consumer guide, the boundary for the fruit and vegetable group was used. The functional unit for coffee and tea was 1 L prepared beverage without any added milk or sweetener. In the guide, the final evaluation of conventionally grown coffee is that it is ‘yellow’ (‘Consume sometimes’), and for organic produce, ‘light green’ (‘Please consume). The evaluation of conventionally grown tea is that it is ‘light green’, and for organic produce, ‘dark green’ (‘Preferably consume this’). For cocoa, the functional unit is 1 kg of cocoa powder and the boundary was taken from the protein group. The final evaluation of conventionally grown cocoa is that it is ‘orange’ (‘Be careful’), and for organically produced cocoa, ‘light green’
Multi-criteria evaluation of plant-based foods -use of environmental footprint and LCA data for consumer guidance
Many consumers are willing to move to a more plant-based diet, as is apparent from the increasing demand for plant-based protein sources on many markets. There is scientific evidence that such diets are associated with lower environmental impacts, especially climate impact, land use, and energy use. However, all food production affects the environment, and there is scope for more sustainable food choices even among plant-based foods. We present a method for environmental multi-criteria evaluation of plant-based products to enable communication through a consumer guide, which was developed in cooperation with World Wide Fund for Nature (WWF) Sweden and involves a real-life case of implementation. The guide included 90 products, divided into five product groups. Four environmental impact categories were evaluated (climate impact, biodiversity impact, water use, pesticide use), to give a fuller, more complex picture of potential environmental impacts of plant-based products than when evaluating only one impact category, such as climate impact. Available environmental footprint data and LCA data adapted for the specific consumer market (Sweden) were used. A method for calculating absolute sustainability thresholds for single products was developed, based on newly published global sustainability boundaries for the food system (Willett et al., 2019). To account for the different dietary functions of food, different thresholds for evaluating different food groups were applied, thus accounting for the role, and to some extent the nutrient content, of different food products. This enabled evaluation of foods based on the same grounds, i.e., using the global sustainability boundaries and the same functional unit for all food products (1 kg of food at a store in Sweden), while visualizing differences in environmental impacts of products within a certain food group. This revealed the best choice of protein sources, vegetables, etc. The method provides a way to use large amounts of data of varying quality, and reduces the complexity in evaluating the environmental impacts of food. It therefore hopefully facilitates sustainable plant-based food choices, for more environmentally sustainable food consumption. (C) 2020 The Author(s). Published by Elsevier Ltd
Environmental impact of plant-based foods – data collection for the development of a consumer guide for plant-based foods
The current food system puts enormous pressures on natural ecosystems. To mitigate these pressures, three overarching strategies are necessary – improvements in production, reductions in food waste and food losses, and dietary change (Willett et al., 2019; Röös et al., 2017). The focus has long been on reductions in meat and dairy in Westernized diets, as animal products have substantially higher climate impacts than most plant-based foods (Moberg et al., 2020). However, there is increasing interest in the sustainability of plant-based foods, reaching beyond the climate impact. For example, concerns have been raised about water and pesticide use in fruit, nut, and vegetable production, high energy use in ready-made food production, and high emissions from products transported over long distances. To provide guidance on such issues, WWF Sweden initiated development of a new consumer guide for plant-based products in a project called ‘World-class Veggie’ (‘Vego i världsklass’). The Vego-guide will complement their current consumer guides on meat (Spendrup et al., 2019; Röös et al., 2014) and fish. This report was prepared for WWF Sweden, to provide scientific background information for its consumer guide on plant-based products targeting Swedish consumers. The remainder of the report is structured as follows: Chapter 2 describes the methodology used for collecting data for the Vego-guide. Chapter 3 presents the results obtained for individual plant-based products and Chapter 4 presents more general results. A short concluding discussion is provided in Chapter 5. A comprehensive set of appendices (Appendix A1-A8), providing examples of data from all underlying studies for all individual products and specific details on the methodology used in the studies, is provided at the end of the report. Motives and reasoning behind selection of environmental impact categories, the establishment of limits and criteria for the different environmental impact categories, and a description of the underlying work in development of the consumer guide are presented in a separate scientific paper (Karlsson Potter & Röös, manuscript)
Climate Assessment of Vegetable Oil and Biodiesel from Camelina Grown as an Intermediate Crop in Cereal-Based Crop Rotations in Cold Climate Regions
The oilseed crop winter camelina (Camelina sativa) is attracting increasing interest for biofuel production. This study assessed the climate impacts of growing camelina as an intermediate crop in northern Europe (Sweden) for the production of vegetable oil and biofuel. Climate impacts were analyzed using life cycle assessment (LCA), while impacts on biodiversity and eutrophication were discussed. Three functional units were considered: 1 ha of land use, 1 kg of oil, and 1 MJ biofuel (hydrogenated vegetable oil, HVO). The results showed that dry matter yield over the whole crop rotation was higher in the camelina crop rotation, despite the lower yield of peas due to relay cropping with camelina. In the whole camelina crop rotation, fat production more than doubled, protein and fiber production marginally increased, and the production of carbohydrates decreased. Higher climate impacts related to field operations and fertilizer use in the camelina crop rotation, with associated N2O emissions, were compensated for by increased soil carbon accumulation due to the increased return of organic matter from the additional crop in the rotation. The total climate impact was around 0.5 kg CO2 eq/kg camelina oil when macronutrient allocation was used. The global warming potential was 15 g CO2 eq/MJ HVO, or 27 g CO2 eq/MJ HVO when soil organic carbon effects were not included, representing an 84% and 71% reduction, respectively, compared with fossil fuels
From straw to salmon: a technical design and energy balance for production of yeast oil for fish feed from wheat straw
BackgroundAquaculture is a major user of plant-derived feed ingredients, such as vegetable oil. Production of vegetable oil and protein is generally more energy-intensive than production of the marine ingredients they replace, so increasing inclusion of vegetable ingredients increases the energy demand of the feed. Microbial oils, such as yeast oil made by fermentation of lignocellulosic hydrolysate, have been proposed as a complement to plant oils, but energy assessments of microbial oil production are needed. This study presents a mass and energy balance for a biorefinery producing yeast oil through conversion of wheat straw hydrolysate, with co-production of biomethane and power.ResultsThe results showed that 1 tonne of yeast oil (37 GJ) would require 9.2 tonnes of straw, 14.7 GJ in fossil primary energy demand, 14.6 GJ of process electricity and 13.3 GJ of process heat, while 21.5 GJ of biomethane (430 kg) and 6 GJ of excess power would be generated simultaneously. By applying economic allocation, the fossil primary energy demand was estimated to 11.9 GJ per tonne oil.ConclusionsFossil primary energy demand for yeast oil in the four scenarios studied was estimated to be 10-38% lower than for the commonly used rapeseed oil and process energy demand could be met by parallel combustion of lignin residues. Therefore, feed oil can be produced from existing non-food biomass without causing agricultural expansion
Future climate impacts of sodium-ion batteries
Sodium-ion batteries (SIBs) have emerged as an alternative to lithium-ion batteries (LIBs) due to their promising performance in terms of battery cycle lifetime, safety, operating in wider temperature range, as well as the abundant and low-cost of sodium resources. This study evaluated the climate impacts of three SIBs, and compared to two LIBs under four scenarios with considering potential changes in battery performance and background productions between 2020 and 2050. To ensure a fair comparison, all batteries were modeled in the 21,700 form, and a battery dimensioning model was developed to calculate the required amount of components for each battery. We found that equal to lower GHG emissions result from the use of SIBs compared to LIBs under optimal performance scenarios. From 2020 to 2050, the climate impacts of SIBs decreased by 43-57 %. The relative contribution of the battery manufacturing process decreases from 18-32 % to 2-4 % due to the increasingly share of clean energy in the electricity grid, while the relative contribution of key battery component materials increases over time, especially for cathode active materials. These results emphasize the significance of decarbonizing the electric grid, and suggest that future investment in SIBs is promising from an environmental point of view
Energy performance of compressed biomethane gas production from co-digestion of Salix and dairy manure: factoring differences between Salix varieties
Biogas from anaerobic digestion is a versatile energy carrier that can be upgraded to compressed biomethane gas (CBG) as a renewable and sustainable alternative to natural gas. Organic residues and energy crops are predicted to be major sources of bioenergy production in the future. Pre-treatment can reduce the recalcitrance of lignocellulosic energy crops such as Salix to anaerobic digestion, making it a potential biogas feedstock. This lignocellulosic material can be co-digested with animal manure, which has the complementary effect of increasing volumetric biogas yield. Salix varieties exhibit variations in yield, composition and biomethane potential values, which can have a significant effect on the overall biogas production system. This study assessed the impact of Salix varietal differences on the overall mass and energy balance of a co-digestion system using steam pre-treated Salix biomass and dairy manure (DaM) to produce CBG as the final product. Six commercial Salix varieties cultivated under unfertilised and fertilised conditions were compared. Energy and mass flows along this total process chain, comprising Salix cultivation, steam pre-treatment, biogas production and biogas upgrading to CBG, were evaluated. Two scenarios were considered: a base scenario without heat recovery and a scenario with heat recovery. The results showed that Salix variety had a significant effect on energy output-input ratio (R), with R values in the base scenario of 1.57-1.88 and in the heat recovery scenario of 2.36-2.94. In both scenarios, unfertilised var. Tordis was the best energy performer, while the fertilised var. Jorr was the worst. Based on this energy performance, Salix could be a feasible feedstock for co-digestion with DaM, although its R value was at the lower end of the range reported previously for energy crops
Prospective life cycle assessment of a flexible all-organic battery
Strong interest from researchers and industry is accelerating development of flexible energy storage technologies for future flexible devices. It is critical to consider the environmental perspective in early development of new emerging technologies. In this study, cradle-to-factory gate prospective life cycle assessment (LCA) was performed on production of an all-organic battery with conductive redox polymers as electrode material. To gain a better understanding of the environmental performance of the all-organic battery, a flexible lithium-ion (Li-ion) battery with lithium titanate oxide and lithium cobalt oxide as electrode active materials was modeled as reference. Main environmental impacts of the all-organic battery were attributable to anode and cathode production, with electrode backbones being the main contributors. Solvents, catalysts, waste treatment, energy, and bromine were key individual contributors. Comparison with the flexible Li-ion battery indicated inferior environmental performance of the all-organic battery due to its relatively low specific energy (Wh/kg) and large amount of materials needed for production of its electrode backbones. Sensitivity analysis showed that changing scaling-up parameters and the production route of 3,4-ethylenedioxythiophene (a precursor of electrode backbones) strongly influenced the results. In order to lower the environmental impacts of the all-organic battery, future research should focus on designing a short production chain with lower material inputs of electrode backbones, increasing battery cycle life, and improving the specific energy of the battery. In addition, relevant recommendations were provided for prospective LCAs of upscaled systems
Environmental assessment of diets: overview and guidance on indicator choice
Comprehensive but interpretable assessment of the environmental performance of diets involves choosing a set of appropriate indicators. Current knowledge and data gaps on the origin of dietary foodstuffs restrict use of indicators relying on site-specific information. This Personal View summarises commonly used indicators for assessing the environmental performance of diets, briefly outlines their benefits and drawbacks, and provides recommendations on indicator choices for actors across multiple fields involved in activities that include the environmental assessment of diets. We then provide recommendations on indicator choices for actors across multiple fields involved in activities that use environmental assessments, such as health and nutrition experts, policy makers, decision makers, and privatesector and public-sector sustainability officers. We recommend that environmental assessment of diets should include indicators for at least the five following areas: climate change, biosphere integrity, blue water consump tion, novel entities, and impacts on natural resources (especially wild fish stocks), to capture important environ mental trade-offs. If more indicators can be handled in the assessment, indicators to capture impacts related to land use quantity and quality and green water consumption should be used. For ambitious assessments, indicators related to biogeochemical flows, stratospheric ozone depletion, and energy use can be added
Soil Carbon Modelling in Salix Biomass Plantations: Variety Determines Carbon Sequestration and Climate Impacts
Short-rotation coppice (SRC) Salix plantations have the potential to provide fast-growing biomass feedstock with significant soil and climate mitigation benefits. Salix varieties exhibit significant variation in their physiological traits, growth patterns and soil ecology—but the effects of these variations have rarely been studied from a systems perspective. This study analyses the influence of variety on soil organic carbon (SOC) dynamics and climate impacts from Salix cultivation for heat production for a Swedish site with specific conditions. Soil carbon modelling was combined with a life cycle assessment (LCA) approach to quantify SOC sequestration and climate impacts over a 50-year period. The analysis used data from a Swedish field trial of six Salix varieties grown under fertilized and unfertilized treatments on Vertic Cambisols during 2001–2018. The Salix systems were compared with a reference case where heat is produced from natural gas and green fallow was the land use alternative. Climate impacts were determined using time-dependent LCA methodology—on a land-use (per hectare) and delivered energy unit (per MJheat) basis. All Salix varieties and treatments increased SOC, but the magnitude depended on the variety. Fertilization led to lower carbon sequestration than the equivalent unfertilized case. There was no clear relationship between biomass yield and SOC increase. In comparison with reference cases, all Salix varieties had significant potential for climate change mitigation. From a land-use perspective, high yield was the most important determining factor, followed by SOC sequestration, therefore high-yielding fertilized varieties such as ‘Tordis’, ‘Tora’ and ‘Björn’ performed best. On an energy-delivered basis, SOC sequestration potential was the determining factor for the climate change mitigation effect, with unfertilized ‘Jorr’ and ‘Loden’ outperforming the other varieties. These results show that Salix variety has a strong influence on SOC sequestration potential, biomass yield, growth pattern, response to fertilization and, ultimately, climate impact