A comparative study of carbon footprint and assessment standards

Transcription

1 *Corresponding author: A comparative study of carbon footprint and assessment standards... Tao Gao *, Qing Liu and Jianping Wang Institute of Project Management, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou, China... Abstract This paper focuses on the research methods and steps involved in carrying out studies on different types of carbon footprints. Furthermore, a comparative study of different carbon footprint assessment standards was carried out to identify their similarities, differences and deficiencies. Goals, principles, research boundaries, calculation methods, data selection and other aspects of organizations footprint and product carbon footprint were analysed, respectively. Organizations carbon footprint assessment standards ISO14064 and Greenhouse Gas (GHG) protocol and product carbon footprint assessment standards PAS2050, TSQ0010, ISO14047 and Product and Supply Chain GHG Protocol were analysed comparatively. The selection of GHG, system settings, quantification and carbon footprint, selection of date and treatment of specific emissions are the most important part of the study of the carbon footprint and assessment standards, especially for organizations and products. Guidelines had been made on these issues from existing assessment standards, but further improvement is still needed. Keywords: carbon footprint; carbon emissions; assessment standards; comparative study Received 28 February 2013; revised 23 April 2013; accepted 24 April INTRODUCTION Global warming is a fact, and evolves into a full range of issues of politics, economy, society, technology, environment and ecology on a global scale from a single scientific problem [1]. It becomes one of the tremendous challenges for human being. Global warming and a series of problems have aroused intense concerns of the international community. A series of international conventions like the United Nations Framework Convention on Climate Change (1992), The Kyoto Protocol (1997), Bali roadmap (2007), Copenhagen Agreement (2009) were signed, which reflect the determination and efforts by the government in response to global warming. According to consensus, countries have made commitments to emission reductions and action plan. Thus, the innovative concepts of low-carbon economy, low-carbon city, low-carbon life, carbon trade, carbon tax, means to reduce carbon emissions become the important development strategy of the whole world. Related research studies were carried out by governments, organizations and researchers on the economic, social and other aspects, and all the stakeholders are trying to find a low-carbon development path. Current research studies on the low-carbon issue, focused on emissions accounting and reduction, carbon emissions trading platform, carbon tax and carbon emission policy [2][3][4][5], have made a lot of achievements. The carbon footprint and assessment standard is one of the most basic and crucial research in low-carbon research. However, due to this issue consistent results have not been achieved yet, and hence, concerned research were greatly affected. Research on the carbon footprint and assessment standards has become a hot topic for governments and researchers. This paper focuses on the research methods and steps involved in carrying out studies on different types of carbon footprints. Furthermore, a comparative study of different carbon footprint assessment standards was carried out to identify their similarities, differences and deficiencies. 2 BACKGROUND 2.1 Concept of carbon footprints The carbon footprint originates from the concept of ecological footprint, which is a measure of human demand on the Earth s ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet s ecological capacity to regenerate. It represents the amount of biologically productive land and sea area necessary to supply the resources a International Journal of Low-Carbon Technologies 2014, 9, # The Author Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( 4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com doi: /ijlct/ctt041 Advance Access Publication 25 June

2 T. Gao et al. human population consumes, and to assimilate the associated waste. Using this assessment, it is possible to estimate how much of the Earth (or how many planet Earths) it would take to support humanity if everybody followed a given lifestyle. However, a widely accepted and concrete definition of a carbon footprintdoesnotexistatpresent.butthenotionofwhatafootprint is does exist. A mostly recognized concept was proposed by Wiedmann et al.: the carbon footprint is a measure of the total amount of carbon dioxide emissions directly and indirectly caused by an activity or accumulated over the life stages of a product. Meanwhile, the carbon footprint is a measure of carbon dioxide emissions [6][7]. 2.2 Classifications and methods of carbon footprints The carbon footprint mainly applies to personal, products, organizations, cities and countries, etc [6][7][8]. A personal carbon footprint is carbon dioxide emissions caused by each person s clothing, food, housing and traffic of daily life. A product carbon footprint measures the greenhouse gas (GHG) emissions over the entire life of a product (goods or services), from the extraction of raw materials and manufacturing right through to its use and the final re-use, recycling or disposal. An organizational carbon footprint measures the GHG emissions from all the activities across the organization, including energy used in buildings, industrial processes and company vehicles. A country carbon footprint focuses on carbon dioxide emissions in the entire country generated by the overall consumption of materials and energy, vegetation and other carbon sequestrations, as well as the indirect and direct emissions caused by import and export activities, to analyse the carbon dioxide emissions of the entire country. Different footprint boundaries of person, product, organization and country are illustrated in Figure 1. Meanwhile, there are some crossovers among the four types. For example, the production process itself is part of the product life cycle, but would also be included in the organizational footprint [9]. The methods used to determine the carbon footprint should not be specified in the definition. It is only necessary that the method satisfactorily meets the requirements of the definition. So a carbon footprint can be analysed for various different functional units at different scales and using different methods. There are three principal methods to calculate carbon emissions: input output (IO) analysis [10][11][12][13], life-cycle assessment (LCA) [14][15] and IO LCA. The method depends on a functional unit via scale in practice (Figure 2) [16]. Consumer products prefer bottom-up LCA, while studies at the national level would apply top-down IO analysis. Hybrid methods which combine the strength of both LCA and IOA are an active area of research and are being increasingly used in practice. 2.3 Assessment standards of carbon footprints In order to make the results of carbon emissions accounting comparable, governments and international organizations, such as the International Organization for Standardization (ISO), the World Resources Institute (WRI), the World Business Council for Sustainable Development (WBCSD) and the British Standards Institution (BSI), have introduced different kinds of carbon footprint assessment standards mainly for organizations and products through a large number of research studies since the end of the last century. After years of development, a higher awareness of assessment standards of carbon footprint, such as ISO14064, GHG Protocol, PAS2050, has been created. Implementation of these standards played a huge role in promoting global carbon emission reduction. However, there are still many problems in the application of these standards, such as carbon emissions accounting methods are uniform. The boundary definition is unscientific, and carbon emission factors are uncertain. These issues need further research and analysis, especially in organization and product fields. 3 ORGANIZATIONAL CARBON FOOTPRINT AND ASSESSMENT STANDARDS 3.1 Organizational carbon footprint An organizational carbon footprint refers to the direct and indirect carbon dioxide emissions generated within the range defined by the organizations (enterprises or projects) Figure 1. Different carbon footprint boundaries of person, product, organization and country. Figure 2. Applications and corresponding methods of the carbon footprint. 238 International Journal of Low-Carbon Technologies 2014, 9,

3 Carbon footprint and assessment standards themselves. The results of assessment can only focus on the carbon emissions inventory of sources and information of greenhouse gas emissions can also be a complete carbon inventory report to public carbon footprints of organizations. Currently, a terminal consumption analysis method based on the IO analysis is the major method for organizational carbon footprint evaluation. The key steps in calculating an organizational carbon footprint are shown in Figure 3: (1) Defining organizational boundaries: It is an important procedure to set clear, explicit boundaries on which parts of the organization are included in the organizational carbon footprint. Meanwhile, an organization may comprise one or more facilities, which usually apply control and equity share approaches to consolidate facility-level GHG emissions and removals at the organization level. (2) Establishing operational boundaries: The operational boundary determines which emission sources will be quantified. It should include the full range of emissions from activities under operational control. All material Scope 1 and 2 emissions should be included, but Scope 3 emissions can be chosen to include [14]. (Scopes 1, 2 and 3 are shown in Figure 2). (3) Calculating carbon footprint: The accuracy of the footprint relies on collating consumption data for all of the emission sources within the established boundary. It is important to clarify any gaps in the data and list any assumptions that have been made in calculating the footprint. The carbon footprint is typically calculated using activity data collated multiplied by standard emissions factors, although there are other calculation methods, such as calculation of the use of models or measurement. (4) Reporting and verifying: Organizations should prepare a report to facilitate inventory verification, participation in a GHG program, or to inform external or internal users. Meanwhile, a third-party verification of carbon footprint was suggested to be carried out, to add credibility and confidence to carbon reporting for public disclosure. Figure 3. Assessment procedures of the organizational carbon footprint. 3.2 Assessment standards of an organizational carbon footprint The GHG Protocol, a collaboration of the WRI and the WBCSD in 2004, provides the foundation for sustainable climate strategies and more efficient, resilient and profitable organizations. The standards follow an inclusive, consensus-based multistakeholder process with balanced participation from businesses, government agencies, non-governmental organizations and academic institutions around the world. For organizations (corporate, project), they introduced The GHG Protocol: A corporate accounting and reporting standard (2004). It provides sectorspecific and general calculation tools and deals with the quantification of GHG reductions, resulting due to the adoption of mitigation methods in its project protocol [17]. In March 2006, ISO released the ISO14064 standard, which is an international standard for the determination of boundaries, quantification, mitigation and removal, used to guide the government and companies to measure and control the GHG emissions, as well as carbon trading, and got a wide range of global consensus [18]. 3.3 Comparative analysis of organizational carbon footprint assessment standards Both GHG Protocol and ISO14064 provide requirements for quantifying the GHG impact of an organization, while harmonization on all qualification methodologies was sought during the development of both standards, some minor differences do remain. Table 1 provides the details of each aspect of the methodologies, the differences between them and estimates whether the difference may affect the final result. By comparative analysis of the two organizations carbon footprint assessment standards, some differences can be seen. The GHG Protocol is the first standard for corporate GHG emissions evaluation. As a voluntary initiative, the GHG Protocol not only pays attention to the procedure of analysis, while a greater emphasis on analysis results, which are utilized for emissions reduction and carbon trading. As an international standard, ISO14064, formed on the basis of the GHG Protocol, is focused on the guiding, framework and the certification process. So, it is mainly used for corporate GHG accounting certification to reflect the corporate social responsibility. Both of the standards select the six GHGs in the Kyoto Protocol. For the setting of the system boundaries, two standards have the same organizational boundary settings; the difference is the settings of the operational boundary. As for the quantization of carbon footprint, the two standards are given several different quantization methods. However, the quantization based on GHG activity data multiplied by GHG emission or removal factors is recommended and widely used. Meanwhile, owing to several complementary standards had been published, such as the GHG Protocol for Project Accounting (2005), Land Use, Land-Use Change and Forestry Guidance for GHG Project Accounting (2006), Guidelines for Quantifying GHG Reductions from Grid-Connected Electricity Projects (2007) and Corporate Scope 3 (value chain) Accounting and Reporting (2011), the selection International Journal of Low-Carbon Technologies 2014, 9,

4 T. Gao et al. Table 1. Contrastive analysis of the GHG Protocol and ISO ISO14064 GHG protocol Essential information Publisher ISO WBCSD&WRI Date , 2011 (revise) Type Official official Availability Instructional operability Property International standard Voluntary initiatives standard Objects Organizations Organizations Applications Mainly used in industry enterprises Various industries, governments, (NGOs), carbon trading platform Goal, scope and principle Goal Specifies principles and requirements for the design, development, management, reporting and verification of an organization s GHG inventory. Principle Essentially the same drawing on ISO 14044, including relevance, completeness, consistency, accuracy and transparency. GHG Six GHGs in the Kyoto Protocol GWP The second report of IPCC (1996) System boundary Organizational Same methods to consolidate organization facility-level GHG emissions and removals: by control or by equity share. boundary Operation Both divide the whole emissions to three parts: direct emission, energy indirect emission and other indirect emissions. boundary Energy indirect emission was denoted as indirect emissions from the generation of imported electricity, heat or steam consumed by the organization. Energy indirect emission was denoted as indirect emissions only from the generation of imported electricity consumed by the organization. Quantification Quantization Calculation, detection, combination of detection and calculation. method Mainly use GHG activity data multiplied by GHG emission or removal factors Refer to emission factors and direct monitoring, as well as cross-industry tools and industry-specific tools. Double counting Not expected The method was proposed to avoid double counting and collection of GHG activity data and emission factors are more clear and operational when using the GHG Protocol. These complementary standards also provide a specific and operational guidance especially to system boundaries defined, quantization of GHG emission and carbon footprint assessment of specific industries, such as the power industry. 4. PRODUCT CARBON FOOTPRINT AND ASSESSMENT STANDARDS 4.1 Product carbon footprint A product carbon footprint is carbon dioxide emissions caused by products (goods or services) in its life cycle. To achieve this, an LCA method is needed to enhance the credibility and convenience of carbon footprint calculation. ISO released ISO14040/44 standards, developed frameworks and steps for the environmental management standard assessment with the LCA method in Currently, LCA analysis is the major method for project carbon footprint evaluation. The key steps in calculating a product carbon footprint are shown in Figure 4: (1) Product life cycle analysis: it is an essential procedure for carrying out the product life cycle analysis to identify all materials, activities and processes that contribute to the Figure 4. Assessment procedures of the product carbon footprint. chosen product s life cycle. To perform a product life cycle analysis, start by breaking down the selected product s functional unit into its constituent parts. Focus on the most significant inputs first, and identify their respective inputs, manufacturing processes, storage conditions and transport requirements. (2) Defining system boundary: the relevant boundaries for the carbon footprint analysis must be determined after product 240 International Journal of Low-Carbon Technologies 2014, 9,

5 Carbon footprint and assessment standards life cycle analysis had been done to determine which unit processes shall be included within the product carbon footprint study. (3) Calculating carbon footprint: The accuracy of the footprint relies on collating consumption data for all of the emission sources within the system boundary of the entire life cycle of product. The key point in collecting data include material amounts, activities and emission factors across all life cycle stages. Calculated based on the carbon footprint equation may ensure that all input, output and waste are included, without missing. (4) Reporting and communication: Organizations should prepare a report to report the results of the quantification of the product carbon footprint and the achievement of the goal and scope and to demonstrate that the provisions of this standard have been followed. Meanwhile, communication may take the form of a declaration, a label, a claim, a report or a performance tracking report based on product carbon footprint standards. 4.2 Assessment standards of a product carbon footprint The British Standards Institution, Carbon Trust and Department for Environment, Food and Rural Affairs (Defra) published a Publicly Available Specification (PAS) to specify requirements based on LCA and Product Category Rules (PCRs) for assessing the life cycle GHG emissions of goods and services in 2008 (revised in 2011) [19]. In April 2009, The Japanese Ministry of Economy, Trade and Industry issued a Technical Specification TSQ0010 General principles for the assessment and labeling of Carbon Footprint of Products, after a carbon footprint trial project and the criteria for developing CF PCRs were released in March The WBCSD and WRI develop a standard under their GHG Protocol Product/Supply Chain Initiative: A Product Life Cycle Accounting and Reporting Standard [20], meanwhile, issued a Corporate Accounting and Reporting Standard Guidelines for Value Chain (Scope 3) Accounting and Reporting as a complementary standard. Since 2007, ISO started developing an international standard ISO on the Carbon Footprint of Products (Part 1: quantification and Part 2: communication), and there is already a proposal for a standard on the Carbon Footprint of Organizations. Businesses can use the standard to assess the carbon footprint of its products throughout the life cycle; the carbon footprint of information can be used for internal management or external announcement and exchange [21]. The international standard is expected to be formally promulgated in Comparative analysis of product carbon footprint assessment standards The four standards provide principles and requirements for quantifying the GHG impact of a product; while methodologies and procedures of the four standards are similar, there are still some differences. Table 2 shows the details of each aspect of the methodologies, the differences among the four standards. By comparison of the four product carbon footprint assessment standards, we can see that the core content of the study and application of product carbon footprint assessment standards are still concentrated on greenhouse gas choice, system settings, quantification and carbon footprint and treatment of specific emissions and removals and other aspects. Six GHGs in the Kyoto Protocol were selected in the four standards. GHG and ISO can be applied to both B2B and B2Ccarbon footprint assessment, and TS-Q0010 only applies to B2C carbon footprint assessment. The PCR, as outlined in ISO 14025, was preferentially recommended to settle the system boundaries by the four standards. Four standards gave different methods to the quantization product carbon footprint, but quantization based on GHG activity data multiplied by GHG emission or removal factors is suggested and most widely used. Activity data and emission factors can come from either primary or secondary sources. Primary data come from direct measurements on product s life cycle, while secondary data refer to external measurements that are not specific to the product, but rather represent an average or general measurement of similar processes or materials, usually find in types of databases, such as multi-sector life cycle databases, industry-specific databases and country-specific data sources. In order to get an accurate study of product carbon footprint, researchers and organizations paid more attention to specific emissions and removals, such as land use change, delayed emissions, renewable power resources and carbon storage. Treatments of specific emissions and removals are given in the four standards, although the approach is different and not complete. The PAS2050, TSQ0010 and Product Life Cycle Accounting and Reporting Standard have been officially released. Most of the existing carbon footprint assessment cases are carried out based on the PAS2050 assessment standard, while TSQ0010 standards are only used in Japan and the applications of Product Life Cycle Accounting and Reporting Standard have just begun. These three standards are mainly used in the food, drinks, drinks, clothing, cosmetics and other areas of life. At the same time, combined with the existing assessment standards, ISO is being prepared for ISO14047, which is expected to be released in CONCLUSION The carbon footprint has started becoming synonymous to a comprehensive GHG account, over the life cycle stages of any product or activity. The carbon footprint study is the basis of low-carbon research. The carbon footprint has been commercialized and is being utilized by organizations to count themselves and their products carbon and adopt measures to cut down emissions, to meet the green consumer expectations of consumers or governmental request, and provides enormous International Journal of Low-Carbon Technologies 2014, 9,

6 T. Gao et al. Table 2. Contrastive analysis of assessment standards of product carbon footprint. PAS 2050 TS-Q 0010 Product Life Cycle Accounting and Reporting Standard ISO14047 (As far as known) Essential information Organization BSI JIS WBCSD&WRI ISO Date 2008, Expected to release in 2013 Type version Official version Official version Official version CD edition Operating Operability Operability Operability Instructional availability Properties Open standard Technical regulation Voluntary initiatives International standard Objects Product/serve User fields Mainly used in foods, drinks, clothing and cosmetics, etc. on a global scale Goal, scope and principles GHG Mainly used in foods and consumer goods in Japan Mainly used in foods, drinks and cosmetics, etc. on a global scale Six GHGs in the Kyoto Protocol GWP Fourth report of IPCC (2007) System boundary System boundary B2B&B2C B2C B2B&B2C B2B&B2C Use phase Obligatory; disclose use profile; Included Cradle to Gate or Cradle to Grave Included if product is supplied to the consumer Allocation System boundary expansion; Preference for PCR Adapted from ISO 14044, Adapted from ISO 14044, Economic Spec. rules for EoL Cut off rules 1% of GHG emissions; 95% complete 5% of GHG emissions (to be discussed more) Significance as principle; 80% complete Adapted from ISO 14044:2006, Quantification Function unit Preference for PCR Data quality Specific rules Specific rules Pedigree matrix Pedigree matrix Data type No IO data, transparent process data Prefer process data, but IO data are acceptable if there are no process data. Prefer process data, but IO data are acceptable if there are no process data. Prefer process data, but IO data are acceptable if there are no process data. Quantization Preference for quantization based on GHG activity data multiplied by GHG emission or removal factors. method Treatment of specific emissions and removals Capital goods Excluded Excluded Relevance criterion Relevance criterion Reduction Code of practice require reporting Could be included, if both CFP Important aim, not many rules Not specified are certified. Land use change Describes procedure and provides default soil emissions per country Not specified Proposal to use PAS2050 Proposal to use IPCC guidelines for National GHG inventories Carbon storage Provides calculation method Not specified Major discussion point, probably Probably included included Delayed emissions Describes calculation method Not specified Major discussion point, Probably included Probably included Renewable power resources Describes additionality and double counting in renewable electricity generation Can be included if it is paid as actual cost Not specified Not specified Reporting and communication Communication Not included in PAS, but in the Code Adapted from ISO Not for comparison Adapted from ISO of practice opportunities to encourage enterprises to improve production efficiency and reduce resource consumption and waste, and promote the development of innovation and technology, to help open new business opportunities, and promote corporate social responsibility and achieve sustainable development. However, as carbon footprint reports are increasing in response to business and legal requirements, most of the calculations are following the GHG protocol and PAS worldwide. Since it has been extended to cover the natural system as well, it becomes essential to deal with the unavoidable emissions. The type of GHG, system settings, quantification and carbon footprint, selection of date and treatment of specific emissions are the most important part of the study of the carbon footprint and assessment standards, especially for organizations and products. Guidelines had been made on these issues from existing assessment standards, but it still needs further improvement. Because carbon emission has been commercialized, and has been found to influence businesses, legal guidelines are necessary to guide and monitor these calculations, so that enterprise and their products carbon footprint analysis will be included in the decision-making stage. Meanwhile, as the strong measures and tools for the global problem of climate warm, research of 242 International Journal of Low-Carbon Technologies 2014, 9,

7 Carbon footprint and assessment standards carbon footprint and assessment standards need to be carried out within the global scope, to solve problems such as carbon leakage and border-tax adjustments. FUNDING This work was supported by Soft Science Research Projects of Ministry of Housing and Urban-Rural Development of the People s Republic of China (No R1-15) and Humanities and Social Sciences Fund of Ministry of Education of the People s Republic of China (No. 11YJCZH125). REFERENCES [1] The United Nations Intergovernmental Panel on Climate Change. Climate Change Synthesis Report [R]. IPCC, Geneva, Switzerland, 2007, 10. [2] Lenzen M, et al. Shared producer and consumer responsibility: theory and practice [J]. Ecol Econ 2007;61: [3] Lenzen M, Wood R, Wiedmann T. Uncertainty analysis for multi-region input output models a case study of the UK s carbon footprint. Econ Syst Res 2010;22: [4] Larsen HN, Hertwich EG. The case for consumption-based accounting of greenhouse gas emissions to promote local climate action [J]. Environ Sci Policy 2009;12: [5] Hertwich EG, Peters GP. Carbon footprint of nations: a global, trade-linked analysis. Environ Sci Technol 2009;43: [6] Wiedmann T, Minx J. A definition of Carbon Footprint [J]. ISA Res Rep 2007;7:1 7. [7] Weidema BP, Thrane M, Christensen P, et al. Carbon footprint. [J] Ind Ecol 2008;12:3 6. [8] Finkbeiner M. Carbon footprinting opportunities and threats [J]. Int J Life Cycle Assess 2009;14:91 4. [9] Matthews HS, et al. The importance of carbon footprint estimation boundaries [J]. Environ Sci Technol 2008;42: [10] Huang AY, Lenzen M, Weber C, et al. The role of input output analysis for the screening of corporate carbon footprints. Econ Syst Res 2009;21: [11] Matthews HS, et al. Estimating carbon footprints with input-output models [R]. Department of Civil & Environmental Engineering, Carnegie Mellon University, [12] Minx J, et al. Input output analysis and carbon footprinting: an overview of applications. [J]. Econ Syst Res 2009;21: [13] Wiedmann T, Wood R, Lenzen M, et al. The carbon footprint of the UK results from a multi-region input output model. Econ Syst Res 2010;22: [14] Hammerschlag R, Barbour W. Life-cycle assessment and indirect emission reductions: issues associated with ownership and trading [R]. Institute for Lifecycle Environmental Assessment, Seattle, Washington, USA, [15] Weidema BP, Thrane M, Christensen P, et al. Carbon footprint: A catalyst for life cycle assessment [J]. J Ind Ecol 2008;12:3 6. [16] Peters GP. Carbon footprints and embodied carbon at multiple scales. [J] Curr Opin Environ Sustainability 2010;2: [17] WRI. The greenhouse gas protocol: a corporate accounting and reporting standard (Revised Edition) [M]. World Business Council for Sustainable Development, Geneva, Switzerland, [18] ISO. ISO14064-The greenhouse gas [R]. International Organization for Standardization, Geneva, Switzerland, [19] BSI. PAS 2050-Specification for the Assessment of the Geneva, Switzerland, Life Cycle Greenhouse Gas Emissions of Goods and Services [M]. British Standards Institution, London, UK, [20] WRI. Product life cycle accounting and reporting standard [M]. World Business Council for Sustainable Development, Geneva, Switzerland, [21] ISO. Carbon footprint of products (ISO/CD , Under Development) [R]. International Organization for Standardization, Geneva, Switzerland, International Journal of Low-Carbon Technologies 2014, 9,