Methodology Internet Based Carbon Footprint Calculation Methodology

Transcription

1 Methodology Internet Based Carbon Footprint Calculation Methodology Version 1.0 Baby Bodies NatureTex/Sekem - Alnatura Page 1 of 10

2 Content 1 General information Introduction Goal and scope of a carbon footprint Functional Unit Methodology System boundary definition Allocation with co-production Activity data of inputs and outputs Emission factors and secondary data Transport Exclusions Results of a carbon footprint Annex... 7 Annex 1. Soil emissions...7 Annex 2. Emission factors...9 Page 2 of 10

3 1 General information 1.1 Introduction The objective of this document is to give more insight into the carbon footprint methodology that Soil & More uses for the internet based carbon footprint platform initiated by Cropster, Oxfam, CGIAR, Sustainable Food Laboratory and Soil & More for a range of different crops. It clarifies the underlying methodology that Soil & More uses, while at the moment no official internationally approved standard methodology exists to calculate a carbon footprint of a product. It is meant for transparent communication in the way how carbon footprint assessments are carried out. Methodological decisions, system boundary definition, differences and overlap with other carbon footprint approaches will be explained in this document. As this project is a pilot study, the internet based calculation tool is not directly comparable with a full carbon footprint calculation approach. The core of the calculation though is the same, but in a way the calculation needed to be simplified in order to stay within a time and budget frame. 1.2 Goal and scope of a carbon footprint A carbon footprint will identify the environmental performance of a product related to greenhouse gas emissions. This means that the life cycle of a product is studied and greenhouse gas emissions in the different production stages of a single product are taken into account. The carbon footprint of a product will inform companies or farmers about setting priorities to reduce emissions in the life cycle of a product. 1.3 Functional Unit Soil and More uses a cradle-to-gate approach that includes the greenhouse gas emissions from the primary production stage until 1 kg of a product (or one product) is delivered at a processor, distributor or retailer within in a destined country. Further distribution at the country of destination is not considered within this calculation. 2 Methodology 2.1 System boundary definition Soil and More includes the greenhouse gas emissions that are released during different stages of the life cycle of a product. The inputs and outputs in every production stage are analyzed and emissions related to production and transport are calculated. The emissions that are directly emitted during one stage, but also indirect emissions are taken into account. For instance the combustion of fossil fuels causes a direct emission in a production or transport phase, but the production of fossil fuels is also related to greenhouse gas emissions. The latter one is called an indirect emission. The general system boundaries include the farm-, processing-, distribution-, packaging- and transport level. This study is aiming for a focus on farming level. During the system boundary definition the highest level of completeness and accuracy is strived for, keeping in consideration the cost-affectivity of the inventory. This may be dependent on the availability of primary activity data and secondary data. Page 3 of 10

4 For every production stage the inputs and outputs are inventoried. This means that the yield (of main and co-products) is inventoried, just like the amount and the sink of discarded products. In general the following stages in the life cycle of the product are included: Stage 1: Farming o Energy consumption: electricity, gas and diesel/petrol for tractors and other equipment o Soil emissions (see Annex 1 for the calculation method of direct and indirect soil emissions related to fertilizer use) o Transport to next stage Indirect emissions due to the manufacturing and transport of agricultural inputs Indirect emission due to the generation of used energy Indirect emission due to the production and transport of used fossil fuels Stage 2: Processing, Distribution and packing o Energy consumption: electricity, gas and diesel/petrol use Indirect emissions due to the manufacturing and transport of processing inputs (e.g. packaging materials) Indirect emission due to the generation of used energy Indirect emission due to the production and transport of used fossil fuels Figure 1 System boundaries of the Soil and More methodology. Soil and More includes at least 3 different greenhouse gasses in the carbon footprints that are emitted during different stages of the life cycle of a product: carbon dioxide, methane and nitrous oxide. Other greenhouse gasses like HFCs are included in the footprint if reliable data is present. The Global Warming Potential (GWP) of methane and nitrous oxide are higher than carbon dioxide, this means that they are stronger greenhouse gasses. To enable calculation of the carbon footprint, they are transferred into CO 2 equivalents by multiplying them with the GWP value. Page 4 of 10

5 Table 1 Greenhouse gasses that are taken into account in the Soil and More methodology. Type of gas Chemical formula GWP 100 Carbon dioxide CO 2 1 Methane CH 4 25 Nitrous oxide N 2 O Allocation with co-production Like mentioned above, in many processing steps one raw material is used to produce many different products (co-products) and the upstream emissions (gasses that are emitted in earlier processing steps) should be divided over the different products. According to the ISO standard i and the PAS 2050 ii, allocation with coproduction one should try to avoid this allocation problem by defining sub processes or by applying system expansion. System expansion usually makes the analysis very complex and difficult to understand. Soil and More therefore uses mass allocation and/or economic allocation to divide the upstream emissions over the different co-products. Mass allocation uses the mass balance of the different co-products and economic allocation also uses the economic value of the different products to define the allocation factors. This means that the results will not be identical (table 2). Table 2. Example for the definition of mass and economic allocation factors Mass balance of Relative Economic co-products economic Mass*price allocation and mass value of coproducts factor allocation factor Co-product 1 60% % Co-product 2 40% % Total 100% % To allocate the emissions caused on the whole farm like e.g. electricity, the share fo the area of the calculated product serves as an allocation key. In case there is more than one crop grown within the vegetation period, the time share is considered for further allocation. Additionally an allocation will be carried out, in case there is next to the main crop a second crop cultivated on the same cultivation area. The calculation is carried out the same same way like the shown examples in table 2. Data like yields and prices for harvested main crop has to be given by the farmer. Values of the second crop is taken from databases of the FAO ( 2.3 Activity data of inputs and outputs According to the PAS 2050 and the ISO standards, Soil and More in the first place works with relevant activity data derived from farms, processors and distributors. 2.4 Emission factors and secondary data If no primary activity data is available, Soil and More will use secondary data from competent sources. The emission factors that are used originate from competent sources, like the ELCD and the Gemis database. If an emission factor Page 5 of 10

6 of an ingredient is not in a database, the emission factor is obtained from relevant literature studies. In the case of electricity, the values from the International Energy Agency are used for national grids iii. If this is the case than the following information about the database or used literature is mentioned: 1 Which database is used 2 Age of the data 2.5 Transport The emissions due to transport are specified for the product. For every transport chain the following parameters are determined to calculate the emission per kg transported: Means of transport (road, ocean air) Distance of transport Within this project the local transport from primary production to a processor is limited by choosing the distance and different types of transport vehicles running on diesel or petrol. Values per kg product for 100, 250 and 500 km transport have been created for the local distribution phase after processing within the country. For overseas transport via ocean or air are for the markets also 3 different distribution zones calculated: North America (Housten), Europe (Rotterdam) and Asia (Hongkong). 2.6 Exclusions According to the PAS 2050, Soil & more excludes emissions due to: Travelling of employees to and from normal place of work Human energy requirements Animals providing transport services Transport of consumers to and from retail Furthermore emissions from capital goods (like trucks, airplanes and buildings) are mostly not included in the carbon footprint of a product. The reason for this is that it is too difficult to allocate the production of these capital goods to a certain product and the relative impact on the total footprint is estimated to be small. Land use change (LUC) is worldwide a major source of greenhouse gas emissions, but the methodology how to allocate it to different products is still under development. Soil and More therefore decided to exclude these emissions (see Annex 8 for details). Related to LUC are mainly soil born carbon and N2O emissions. These emissions are also strongly influenced by different soil tillage practices. Due to the necessity of extra data and knowledge about certain parameters of the soil, that had to be outlined within the internet based plattform. 3 Results of a carbon footprint After data gathering, the actual carbon footprint of the products is calculated. The carbon footprint will give insight into the centre of gravity of the emissions due to the production of that specific product. The different causes of greenhouse gas emissions will be summarized which will inform companies about possibilities to reduce greenhouse gas emissions. Page 6 of 10

7 4 Annex Annex 1. Soil emissions Nitrous oxide is emitted in soils due to microbial processes in the soil: denitrification and nitrification. It is a combination of aerobic and anaerobic processes by microorganisms that use nitrogen and organic matter to feed on. Soil and More uses the calculation methodology of soil emissions, described in chapter 11 of the IPCC guidelines on a Tier 1 approach (default methodology) iv. The IPCC guidelines define direct and indirect emissions. The emission factors are dependent on the type of fertilizer, soil type, crop residues and the amount of fertilizer that is used. The following parameters are needed in order to calculate the soil emissions: 1. Fertilizer type used (nitrate or ammonia type) 2. Application of fertilizer (kg N/ha) 3. Compost and Manure application (kg N/ha) Direct emissions The following formula is applied to calculate the direct emissions from agricultural soils: CO2-eq (kg/ha) = Ei/ha*EFi*44/28*298 Ei=netto amount of N applied by source i EFi=emission factor of source i 44/28= conversion factor of N2O-N to N2O 298= GWP value of N2O Table 3. Emission factors of direct soil emissions. EF1 for N additions from mineral fertilisers, organic amendments and crop residues, and N mineralised from mineral soil as a result of loss of soil carbon [kg N2O N (kgn)-1] EF3 for cattle (dairy, non-dairy and buffalo), poultry and pigs [kg N2O N (kg N)-1] EF mineral soil 1% 2% Indirect emissions Indirect soil emissions are emitted due to leaching of nitrogen and deposition of volatilized ammonia. The following formula is applied to calculate indirect soil emissions: CO2-eq (kg/ha)= Ei/ha*EFi*44/28*298 Ei= amount of N from source N EFi= emission factor of source N 44/28= conversion factor of N2O-N to N2O 298= GWP value of N2O Table 4. Emission factors of indirect soil emissions. Source EF Volatilisation and re-deposition of NH3-N and NOx-N) 1% Page 7 of 10

8 Leaching of N2O-N 0,75% Fraction that volatilizes of mineral 10% fertilizers Fraction that volatilizes of organic 20% fertilizers Fraction that leaches (if rain or irrigation> 30% water holding capacity) Crop residues (N2O-N/kg N) 1% Page 8 of 10

9 Annex 2. Emission factors Type Description Emission Factor Unit Source Fuels Diesel 3,179 kgco2e/l DEFRA 2010 Petrol 2,733 kgco2e/l DEFRA 2010 Natural Gas 0,203 kgco2e/kwh DEFRA 2010 Transport Petrol (Class I) up to 1.305t 0,233 kgco2e/km DEFRA t to Petrol (Class II) 1.74t 0,253 kgco2e/km DEFRA 2010 Petrol (Class III) 1.74t to 3.5t 0,307 kgco2e/km DEFRA 2010 Petrol (average) up to 3.5t 0,289 kgco2e/km DEFRA 2010 Diesel (Class I) up to 1.305t 0,188 kgco2e/km DEFRA t to Diesel (Class II) 1.74t 0,270 kgco2e/km DEFRA 2010 Diesel (Class III) 1.74t to 3.5t 0,323 kgco2e/km DEFRA 2010 Diesel (average) up to 3.5t 0,301 kgco2e/km DEFRA 2010 Air 0,733 kgco2e/tkm DEFRA 2010 Sea 0,019 kgco2e/tkm DEFRA 2010 Road 0,095 kgco2e/tkm DEFRA 2010 Materials corrugated board boxes 1,173 kgco2e/kg ABS (very hard plastic) HDPE (plastic bags, shampoo bottles, containers etc) HIPS (polystyrene casings, isolation, piepschuim) LLDPE (plastic wrappings, sealing for food products) Nylon (clothings) PB (tubes) PC PET bottle grade PMMA (glassy like) PVC (building industry) 0,022 kgco2e/kg 1,942 kgco2e/kg 3,482 kgco2e/kg 2,312 kgco2e/kg 0,022 kgco2e/kg 0,022 kgco2e/kg 0,022 kgco2e/kg 3,417 kgco2e/kg 0,022 kgco2e/kg 1,600 kgco2e/kg Fertilizer N-Fertilizer 7,607 kg CO2e/kg N GEMIS Pesticide use P-Fertilizer 1,232 kg CO2e/kg P GEMIS K-Fertilizer 1,180 kg CO2e/kg K GEMIS Limestone or Dolomite 0,306 kg CO2e/kg Ca GEMIS Compost Animal manure Emissions per dose per hectare 4,400 kg CO2e/kg N 0,000 kg CO2e/kg N 20,500 kg CO2e/dose per hectare Electricity Guatemala 0,421 kgco2e/kwh Williams, A.G., Audsley, E. and Sandars, D.L. (2006) Average from Audsley Harmonisation 1997 Source: U.S. Energy Administration, based on data from (IEA), Electricity Database 2007 and CO2 Emissions from Fuel Combustion Database 2006 Page 9 of 10

10 Jamaica Colombia Kenya 0,822 kgco2e/kwh 0,158 kgco2e/kwh 0,394 kgco2e/kwh Source: U.S. Energy Administration, based on data from (IEA), Electricity Database 2007 and CO2 Emissions from Fuel Combustion Database 2006 Source: U.S. Energy Administration, based on data from (IEA), Electricity Database 2007 and CO2 Emissions from Fuel Combustion Database 2006 Source: U.S. Energy Administration, based on data from (IEA), Electricity Database 2007 and CO2 Emissions from Fuel Combustion Database 2006 i ISO 14044, Environmental management-life Cycle assessment-requirements and guidelines. ISO, Geneva. ii PAS Carbon Trust iii International Energy Agency 2004, CO2 Emissions from Fuel Combustion. iv 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Volume 4: agriculture, Forestry and Other Land Use. Chapter 11: N2O emissions from managed soils, and CO2 emissions from lime and urea application. IPCC Page 10 of 10