Carbon footprinting in the UK waste management sector

Abstract

The UK waste management sector is under increasing pressure to measure, report and manage its GHG emissions. In recent years, it has become common for large waste management companies to report their annual carbon footprint, and a sector-specific standard has been developed, the Entreprises pour l’Environnement Protocol. In this article, we have critically evaluated approaches taken within the waste management sector to measure, report and verify its carbon footprint. Although the Entreprises pour l’Environnement Protocol has been made freely available, its use has been limited. With no commonly agreed sector-specific standard, carbon footprinting has become highly subjective. This has resulted in high levels of inconsistency between companies and the reporting of inaccurate, incomplete and noncomparable carbon footprints. Consequently, calculated carbon footprint information is ineffective in guiding corporate GHG management. There is a need for a robust, transparent, commonly agreed waste management sector-specific standard that facilitates accurate measurement, reporting and verification of organizational GHG emissions.

The UK waste management sector is coming under increasing pressure from the public and central government to measure, report and manage its GHG emissions [1–3]. GHG emissions from the sector comprise approximately 3% of the UK’s total [4], with approximately 89% of the sector’s contribution stemming from CH₄ emissions, a potent GHG 25-times more powerful than CO₂ (as measured by global warming potential [GWP] over a 100 year time horizon [GWP₁₀₀] [5], principally arising from landfill gas. However, certain waste management activities have the potential to reduce the sector’s climatic impacts indirectly, either by generating energy, which could substitute an equivalent quantity produced from fossil fuels, or through the recovery of materials. Thus, the challenge for the waste management sector is to maximize its resource efficiency whilst simultaneously reducing its GHG emissions.

Carbon footprinting, a concept increasingly being recognized as a valuable indicator in the field of GHG emissions management, can help waste management companies better assess the link between GHG emissions and their activities. Key aspects of the carbon footprint definition debate are discussed in Wright et al.[6], while Finkbeiner outlines its numerous methodological challenges [7]. We support the definition proposed by Wright et al. that a carbon footprint should be defined as, “a measure of the total amount of CO₂ and CH₄ emissions of a defined population, system or activity, considering all relevant sources, sinks and storage within the spatial and temporal boundary of the population, system or activity of interest” [6].

The waste management sector: scope

The UK waste management sector comprises local authorities, a relatively small number of large private employers and a large number of small-to-medium enterprises (SMEs). Waste management is defined by the 2008 European Waste Framework Directive as, “the collection, transport, recovery and disposal of waste, including the supervision of such operations and the after-care of disposal sites, and including actions taken as a dealer or broker” [8]. Aulakah and Thorpe, following a consultation program with industry representatives, proposed a revision of the 2008 European Waste Framework Directive’s description of the waste management sector, whereby the waste management sector is defined as consisting of local authorities and businesses engaged in one or more of the following activities [9]:

	▪ Re-use of products to divert waste at source;
	▪ Collection and transport;
	▪ Brokerage of waste;
	▪ Sorting and storing;
	▪ Disposal through landfill;
	▪ Disposal through incineration;
	▪ Treatment of waste;
	▪ Recycling and processing of recyclate;
	▪ Composting;
	▪ Energy recovery.

For the purposes of this study, we have adopted the definition of the waste management sector as proposed by Aulakah and Thorpe [9].

The UK waste management sector is dominated by seven large, private multinational groups, namely: Biffa Group Ltd, Cory Environmental Ltd, Shanks Group Plc, Sita UK Ltd, Veolia Environmental Services (UK) Plc, Viridor Waste Management Ltd and Waste Recycling Group Ltd (WRG). These seven companies are estimated to account for over 50% of the waste management market in terms of revenue share [10], and between them they were estimated by the Environmental Services Association (ESA) to have accounted for 8.8 million tonnes of CO₂ equivalent (Mt CO₂e) in 2008, approximately 49% of the waste management sector’s total GHG emissions [1]. Thus, a good indication of how a significant proportion of GHG emissions associated with the waste management sector are being measured and reported, can be obtained by evaluating the carbon footprinting approaches taken by these seven companies.

The aim of this article is to critically evaluate the current approaches taken within the UK waste management sector to measure, report and verify its carbon footprint. We have critically analyzed and evaluated carbon footprint information obtained from the most recently published (as of August 2011) corporate social responsibility (CSR) and/or environmental performance reports (henceforth, carbon footprint reports) of the seven largest UK waste management companies. Current practice has been compared against the GHG Protocol Corporate Standard [11]. Finally, we have critically reviewed current attempts to develop a sector-specific GHG quantification and reporting standards, and analyzed how this protocol addresses key aspects relating to carbon footprinting in the waste management sector.

We have selected the approach of using the most recently published material available for each individual company for two main reasons. First, due to the incipient, developing nature of carbon footprinting practice, the approaches taken by companies to measure and report their carbon footprints are being updated and improved year-on-year. As such, it would contradict the purpose of this study if out-dated material were used – a direct consequence of comparing corporate carbon footprint information against a base year. Second, it was not possible to establish a base year from which carbon footprint information could be reviewed, as Cory Environmental Ltd have not published any carbon footprint information since 2008, a year for which carbon footprint information is not available for one or more other companies under investigation.

Current practice

▪ The Carbon Reduction Commitment & the waste management sector

All industrial sectors have been driven by international, European and national government agreements and commitments to reduce their national GHG emissions. As a signatory to the Kyoto Protocol, the UK is obligated to reduce its emissions of GHGs by 12.5% by 2008–2012, relative to 1990 emissions [12]. Furthermore, the Climate Change Act, the legal framework for the UK’s response to climate change, was passed into law in 2008 and sets a long-term target of reducing national GHG emissions by at least 80% by 2050, relative to 1990 emissions [13]. In order for these targets to be met, the government has introduced a number of initiatives aimed at reducing GHG emissions from industry. In the past, these initiatives (which include Climate Change Agreements, the Climate Change Levy and the EU Emissions Trading Scheme) have focused solely on the most energy-intensive sectors. However, in April 2010, the first government initiative to target GHG emissions abatement in non-energy intensive sectors was brought into force, namely the Carbon Reduction Commitment (CRC) Energy Efficiency Scheme. The aim of the CRC is to drive energy efficiency improvements in the private and public sectors. The CRC is mandatory for organizations that consume more than or equal to 6000 MWh of half-hourly metered electricity per year; most of the large UK waste management companies qualify. During the initial 3-year introductory period, registered companies are required to calculate their GHG emissions based on set guidelines and submit this to the regulatory body (the Environment Agency) in an annual report. The scope of reporting under the CRC extends only to direct CO₂ emissions from combusted fuel used and indirect CO₂ emissions from purchased electricity used. Process emissions are not included, nor are any emissions which derive from transportation or passenger travel. The CRC is concerned solely with CO₂ and excludes emissions of CH₄ – the major contributor to the waste management sector’s GHG emissions.

▪ Voluntary reporting

Over the past 20 years, CSR has become a prominent item on the corporate agenda. With the ever-increasing power and influence of corporations and mounting legislative requirements, CSR provides companies with an opportunity to express the societal benefits of their activities to increasingly environmentally conscious stakeholders and consumers [14,15]. In recent years, large waste management companies have begun to measure their operational GHG emissions and report this information in their annual carbon footprint reports, as a means of demonstrating their commitment to GHG emissions abatement.

A number of protocols and accounting methodologies have been developed that aim to assist organizations in the voluntary reporting of their GHG emissions. The most widely used is the GHG Protocol (revised edition), produced jointly by the World Resources Institute and the World Business Council for Sustainable Development [11]. The GHG Protocol aims to ensure consistency with international reporting schemes and has formed the basis of the UK Department for Environment, Food and Rural Affairs’ Measurement and Reporting of GHG Emissions Guidance for UK Organizations [16], the Carbon Trust Standard [17] and the ISO 14064 series [18–20]. Other voluntary GHG accounting/reporting mechanisms available to UK waste management companies include PAS 2050 and life cycle assessment. A comparison of all the different GHG emissions accounting/reporting mechanisms available to UK waste management companies is shown in Table 1.

▪ The Entreprises pour l’Environnement Protocol

An adaptation of the GHG Protocol has been developed specifically for the waste management sector; namely the Protocol for the Quantification of GHG Emissions from Waste Management Activities (henceforth, the Entreprises pour l’Environnement [EpE] Protocol) [21]. The EpE Protocol was developed by the Entreprises pour l’Environnement Association, a group comprising three French waste management companies: Séché Environnement, Suez Environnement and Veolia Environnemental Services. The EpE Protocol has been made readily accessible to waste management companies; it is free of charge and based in Microsoft Excel (a widely used spreadsheet program). Furthermore, the EpE Protocol complies with all international GHG accounting and reporting standards, including the GHG Protocol and the ISO 14064 series. In the UK, the ESA, a professional organization that represents approximately 80% (by turnover) of the UK’s waste management and secondary resources industry, have contributed to the development of the EpE Protocol and are now seeking the endorsement of the European Federation of Waste Management and Environmental Services to have the protocol form the basis of an internationally agreed reporting tool, to cover all waste management activities.

Despite the support of ESA, adoption of the EpE Protocol by UK waste management companies has been relatively limited. Table 2 shows the methodologies used by each of the seven largest UK waste management companies to calculate their carbon footprints; it can be seen that only three companies (Veolia, Cory and Sita) use the EpE Protocol to calculate and report their carbon footprints (although one company [WRG] uses a variation of the protocol). The other three companies (Biffa, Viridor and Shanks) use their own in-house carbon footprinting methodology. Thus, of these seven companies, there are as many as five different carbon footprint approaches being used.

Carbon footprinting in the waste management sector: key aspects

A consequence of the burgeoning advancement of carbon footprinting is that there is no consensus as to what should actually be included as part of a carbon footprint. Hence, before a carbon footprint can be calculated, a decision must be made as to what data should be included and how it should be reported. Key aspects regarding carbon footprinting in the waste management sector will be discussed within this section.

▪ Temporal boundary selection

Carbon footprinting has a number of temporal elements that affect various aspects of the calculation. Four time-dependent variables must be taken into consideration by waste management companies; these include the reporting time period, GWP time horizon, GHG residence time and fugitive, and time-lagged emissions associated with composting and landfill. Issues concerning the temporal aspects of carbon footprinting are discussed in Gentil et al.[14], Shine [22] and Shine et al.[23].

Temporal boundary selection must be considered when selecting which GWP reference to use. The calculation of GWP for a given GHG depends on, among other things, the lifetime of the gas in the atmosphere. The IPCC release GWP references for 20 (GWP₂₀), 100 (GWP₁₀₀) and 500 (GWP₅₀₀) year time horizons, although GWP₁₀₀ is employed almost universally by reporting methodologies and protocols [24].

Both the GHG Protocol and the EpE Protocol recommend that companies report their GHG emissions based on one year of emission data; a practice to which all seven of the waste management companies investigated in this study adhere. However, there is a lack of consistency between companies in their choice of report period. Whilst the majority of companies report their GHG emissions based on a calendar year (January to December), two companies (Biffa and Viridor) elect to report their GHG emissions over a financial year (April to March). To facilitate the drawing up of timely, annual inter-company carbon footprint comparisons, it is important that there is consistency in the report periods used by waste management companies.

▪ GHG selection

An area of great contention concerning the concept of carbon footprinting refers to the selection of GHGs that should be included in a study. Under the Kyoto Protocol, emissions of six GHGs (CO₂, CH₄, N₂O, HFCs, perfluorocarbons and sulfur hexafluoride) must be reported. The EpE Protocol, although based on the GHG Protocol which covers all six of the GHGs included in the Kyoto Protocol, requires that only emissions of CO₂, CH₄ and N₂O are reported, while the CRC covers only emissions of CO₂.

Table 3 shows a comparison of the selections of GHG, GWP reference and emissions factors by the waste management companies investigated; several different GHG selections are evident. There is consistency between the three companies who use the EpE Protocol to calculate their carbon footprint (Cory, Sita and Veolia), with each including emissions from CO₂, CH₄ and N₂O, while WRG have adapted the EpE Protocol to include CFC emissions. The remaining companies (Biffa, Shanks and Viridor) do not make reference within their external publications as to their GHG selections.

To ensure the consistency and comparability of carbon footprint reports, it is essential that all companies include the same selection of GHGs. Furthermore, any common reporting tool specific to the waste management sector must be both simple to use and accurate [1]. As such, it would be impractical, resource consumptive and overly complicated to include the full array of GHGs, although this approach has been suggested by Moss et al.[25]. It is argued by Wiedmann et al. that, to ensure practicality and clarity, a carbon footprint should ‘exclusively’ quantify emissions of CO₂[26]. However, Wright et al. contend that by omitting CH₄, approximately one fifth of global GHG emissions would be excluded [6]. Furthermore, as CH₄ accounts for approximately 89% of emissions arising from the waste management sector [101], its exclusion would render a carbon footprint meaningless to waste management companies. An accurate carbon footprint that accounts for over 90% of the waste management sector’s total emissions can be attained using only CO₂ and CH₄ emissions data. Companies that wish to spend resources collecting more detailed data can report a climate footprint in addition to their carbon footprint [6]. A climate footprint can be defined as a measure of the total amount of Kyoto GHG (CO₂, CH₄, N₂O, sulfur hexafluoride, perfluorocarbons and HFCs) emissions of a defined population, system or activity, considering all relevant sources, sinks and storage within the spatial and temporal boundary of the population, system or activity of interest [6].

▪ Choice of GWP reference

The GWP is a simple metric that allows for the climatic effects of different GHGs to be compared by representing each given GHG against a CO₂e [5,27]. The first GWP values were published in the IPCC Second Assessment Report (SAR) [28] and were subsequently adopted for the Kyoto Protocol to allow for the inclusion of multiple GHGs in the reporting. Since SAR was published in 1995, GWP values have been updated by the IPCC in their Forth Assessment Report (AR4); a result of an improvement in the calculations and a reported increase in atmospheric concentrations of anthropogenic GHGs [14]. For the waste management sector, the most significant change concerns the GWP for CH₄, which, by the AR4 (GWP CH₄ = 25), had increased by 19% since the SAR (GWP CH₄ = 21).

In order for there to be consistency and comparability between waste management companies it is important that they each use the same GWP reference. Furthermore, to ensure accurate calculations are made, the GWP reference adopted should be that which is most recently published. The GWP reference values used by the seven waste management companies investigated are shown in Table 3. While several companies (Biffa, Shanks and Viridor) do not report what GWP reference they have used, there is consistency between the remaining four companies (Cory, Sita, Veolia and WRG) in using the GWP values published in SAR. The GWP values available in SAR are, since the publication of AR4, outdated and inaccurate, with those companies who continue to use the SAR GWP values underestimating the climatic impact of their CH₄ emissions by almost 20%. There is an argument that suggests companies should continue to use the SAR GWP values until the end of the Kyoto reporting period in 2012 [21]. If this is the case, it is important that waste management companies are proactive in adopting the updated and accurate AR4 GWP values, to ensure that the true climatic impact of their activities is quantified and reported.

▪ Emissions factors

When direct measurements of GHG emissions associated with an activity cannot be obtained, companies may elect to apply generic emissions factors. Emissions factors are used to estimate the amount of GHG emissions associated with a certain activity (e.g., the mass of CO₂ released through the combustion of 1 l diesel fuel consumed in a motor vehicle engine), and are amalgamated data based on previous detailed studies of a particular activity [6,25]. The use of these generic emissions factors is in many instances the only feasible means available for companies to determine the GHG emissions associated with their activities.

It is important for companies who use emissions factors to select those that are the most appropriate and specific to their organization, and pay particular attention to the technical, temporal and geographical validities of the emissions factors [14]. As such, it is important that companies understand the range of factors that influence the formulation of emissions factors. Factors that affect the technical validity of emissions factors include, amongst other things, the operating age of the emissions source, its operational efficiency and its technological capacity. The geographic validity of an emissions factor is affected most importantly by the waste composition used to generate the emission factor. Waste composition influences the amount of emissions associated with a waste disposal approach due to the different carbon contents of each unique waste type. Waste composition varies between regions due to different socio-economic factors and specific local waste management policy [14,29]. In order for an accurate carbon footprint to be calculated, it is important that companies apply emissions factors generated from studies conducted as locally as possible.

The EpE Protocol calculation tool allows waste management companies to calculate the GHG emissions associated with their activities through applying generic emissions factors. However, the majority of the calculator’s default emissions factors are based on French publications; as such, their geographic validity to UK waste management companies is questionable. To ensure greater consistency and accuracy in UK waste management companies’ carbon footprint reports, it is essential that UK-specific emissions factors, namely those published by Department for Environment, Food and Rural Affairs or other appropriate organizations, are applied as extensively as possible.

▪ Biogenic carbon & carbon sequestration

A further area of contention surrounding the carbon footprinting of waste management activities concerns carbon of biogenic origin and its inclusion in carbon footprint calculations. It can be generally assumed that the EU municipal solid waste stream contains approximately 25% carbon; approximately 50% of this is biogenic [30–32]. Biogenic carbon is bound in a variety of materials, including food waste, garden waste, paper, cardboard, textiles and wood waste.

It is currently recognized international practice that CO₂ originating from a biogenic source should be treated differently to CO₂ from a fossil source [33]. The IPCC recommends that CO_2fossil emissions are assigned a GWP of one (GWP₁₀₀ = 1), while CO_2biogenic emissions should be assigned a GWP of zero (GWP₁₀₀ = 0) [34]. All GHG emissions measurement and reporting protocols and standards adhere to this principle. The reasoning behind CO_2biogenic being assigned a GWP of zero is that the creation of biomass has removed an equal volume of atmospheric CO₂ to that which is released when biomass is combusted [35].

This has become an area of debate within the literature. Both Hogg [36] and Friedland and Gillingham [37] argue that the heat trapping potential of CO_2biogenic is no different to that of CO_2fossil; thus, the climate reacts no differently to emissions of CO_2biogenic than to CO_2fossil. Rabl furthers this point, reasoning that by assigning CO_2biogenic a GWP of 0, one could burn down a tropical forest and report no greater a carbon footprint than were one to preserve said tropical forest; an absurd conclusion [38].

The issue of biogenic carbon is further compounded in the context of carbon storage. CO₂ is considered to be in long-term storage if it is bound to soil or sequestered in landfill for longer than 100 years [33]. As such, sequestered CO₂ is almost universally assigned a negative GWP [35]; for example, assigning CO_2biogenic bound in soils or sequestered in landfill a GWP of -3.67 (44/12) kg CO₂e. However, if CO_2biogenic emissions are assigned a GWP of 0, which implies that their release into the atmosphere will have no heat trapping effect, then it stands to reason that the long-term storage of CO_2biogenic in landfill or soils has a heat trapping potential no different to that of CO_2biogenic released into the atmosphere. Therefore, either the sequestration of CO_2biogenic should be assigned a GWP of 0, essentially excluding them from a carbon footprint calculation, or emissions of CO_2biogenic to atmosphere should be assigned a suitable positive GWP. However, determining a suitable GWP for CO_2biogenic and including it in carbon footprint calculations is recognized as a challenge and is an area much in need of further research [39].

▪ System boundary selection

Before a company can undertake a carbon footprint of their activities, it is essential that they outline their system boundaries. A system boundary can be defined as a set of criteria that indicate and fix a limit or extent to the population, system or activity under consideration. Presently, the selection of system boundaries is highly subjective, as there is no universally accepted standard for system boundary definition. Consequently, the quality of system boundary definition, as well as its reporting in carbon footprint reports, is currently poor [40]. Of the companies investigated, only WRG coherently outlined their system boundaries in their carbon footprint report. Without well-defined system boundaries, the results of a carbon footprint study are practically valueless as a tool to guide corporate GHG management strategy. Furthermore, this lack of consistency in boundary definition prevents companies, potential clients, regulators, shareholders and the public comparing GHG emissions per capita. To enable the carbon footprint to be an effective tool for guiding corporate GHG management, it is essential that the waste management sector agree on a universally-accepted approach to the defining and reporting of system boundaries.

The GHG Protocol outlines two approaches an organization can take in order to define their system boundaries: the ‘equity share’ and the ‘control’ approaches. Under the equity share approach, companies account for GHG emissions associated with an activity based on their percentage ownership of that operation; this approach aligns with international financial reporting standards. Under the control approach, companies account for all GHG emissions associated with activities over which it has control, either financially or operationally [11].

The EpE Protocol requires that users adopt the operational control approach, whereby the user is deemed to have operational control of a source if they exert a dominant influence over that source. However, this approach faces a number of challenges. The level of influence and control exerted over a particular source will vary over time and from company to company (e.g., a source may be controlled by one company for one year, but then control may shift to a different company the following year); as a result, the validity of comparisons both between and within companies is compromised [41,42]. Furthermore, by allocating GHG emissions to their immediate producers, control approaches fail to address the intuitive conviction that, in a complex system involving many independent actors such as waste management, responsibility for emissions should be shared jointly between involved actors.

‘Shared responsibility’ approaches have been presented by Gallego and Lenzen [43] and Lenzen et al.[44]. However, the application of a shared responsibility approach in the waste management sector may be impractical at present as, in order to determine the appropriate responsibility of each independent actor, each company would require GHG emissions information for their supply chain, both upstream and downstream [43]. This level of GHG emissions information is unlikely to be achieved through voluntary carbon footprint reporting in its current state, as companies largely consider the collection of supply chain (Scope 3) emissions data as an unnecessary financial burden, particularly given the dominant corporate focus on only quantifying emissions from operational sources. It is likely that complete system GHG information could only be obtained via mandatory disclosure of corporate carbon footprints, with quantification and reporting based on a comprehensive, sector-specific protocol.

▪ Scope 3 emissions

The majority of quantification and reporting protocols and standards consider emissions in terms of several overarching Scopes. Scope 1 emissions are those that arise as a direct result of processes or activities undertaken by a company (e.g., CH₄ emissions from a company owned landfill site). Scope 2 accounts for upstream emissions associated with a company’s consumption of purchased electricity or heat. Scope 3 emissions expand the system boundaries yet further, to include indirect emissions arising both upstream and downstream as a consequence of a company’s activities [11,16].

Whilst both the GHG Protocol and the EpE Protocol regard the measurement and reporting of Scope 3 emissions as optional practice, the inclusion of Scope 3 emissions in a carbon footprint calculation can provide waste management companies with a more complete picture of their environmental impact [45,46]. Presently, only Biffa and Cory report any of their Scope 3 emissions; both report GHG emissions from corporate business travel.

One possible reason why so few companies measure and report their Scope 3 emissions stems from the widespread adoption of the operational control approach to system boundary definition, through which supply chain emissions are, by definition, excluded. Cerin stated that if companies are undertaking carbon footprint assessments as an indicator for an effective GHG management system then, “it is insufficient to merely report on the CO₂ emissions limited to the judicial borders of the company” [47]. Furthermore, Peters explained how the adoption of the operational control approach and exclusion of Scope 3 emissions leads to ‘perverse’ incentives for companies to outsource emissions-intensive activities (thereby transferring the emissions from Scope 1 to Scope 3) [46].

There appears to be a perception amongst waste management companies that the measurement and monitoring of Scope 3 emissions is a data intensive, superfluous process. However, the inclusion of Scope 3 emissions has been shown to substantially improve the quality of information a carbon footprint can provide to a company. Huang et al. reported that by providing sector-specific guidance for companies to identify and measure the GHG emissions of their most important upstream suppliers, companies that use this guidance can achieve a total carbon footprint capture rate of 50–95% [48]. Although the measurement and reporting of Scope 3 emissions may seem at first a daunting endeavor, in terms of fulfilling the overarching purpose of voluntary carbon footprint reporting (namely, to act as a tool to assist and inform corporate GHG management), such practice may be invaluable to waste management companies [49].

▪ Double counting

Another issue, which occurs as a direct result of the subjectivity of system boundary definition in the waste management sector, is that of double counting. Double counting occurs as a result of two scenarios. First, when two or more companies hold interests in the same joint operation and use different consolidation approaches; for example, Company A follows the operational control approach while Company B uses the financial control approach. If Company B holds financial ownership of an emissions source, but Company A controls operations of said source, then said source’s emissions will be counted by both companies in their respective carbon footprints [11]. Second, if a company includes its supply chain (Scope 3) emissions and other companies in its supply chain do the same, then these emissions will be double counted [46]. Consequently, when the carbon footprints of individual waste management companies are added up, they equal a greater carbon footprint than the sector’s carbon footprint [44]. Double counting results in an inaccurate depiction of the waste management sector’s climatic impact and infringes upon the sector’s ability to develop effective GHG management strategies. For double counting to be avoided, it is essential that every organization involved in the waste management system adopts a consistent approach to their system boundary definition.

▪ Avoided emissions

Certain waste management activities are recognized as having an indirect contribution to climate change mitigation through the generation of energy from waste or the re-use/recycling of materials or fuels [50,51]. These activities prevent the need to use raw materials or energy from fossil sources, and as such their GHG emissions are considered as being avoided. However, there are several issues with regards to avoided emissions that the waste management sector must consider; what should be counted as an avoided emission, how avoided emissions should be calculated and, finally, how avoided emissions should be reported.

Avoided emissions sources as reported by the companies investigated are shown in Table 4; there is lack of consistency as to which avoided emissions sources are included. Cory do not report any avoided emissions, whereas Veolia include five different sources of avoided emissions (materials separated for re-use/recycling, renewable energy exports, renewable energy purchased, waste-derived fuels produced and sold, and CH₄ emissions avoided by landfill gas combustion). Of the four companies who, to some degree, use the EpE Protocol methodology to calculate their carbon footprints, only one company (WRG) adheres to the EpE Protocol’s recommendations regarding what should be included as an avoided emission. Veolia, for instance, were part of the development team behind the EpE Protocol, yet they go against its recommendations and include ‘CH₄ emissions avoided by landfill gas combustion’ and ‘renewable energy purchased’ as additional sources of avoided emissions.

A further issue lies in the calculation of avoided emissions. The determination of avoided emissions associated with a given waste management activity is highly dependent upon the calculation methodology used [52]. Presently, there is a lack of consistency and accuracy in the methodologies used by large waste management companies. For example, Shanks include materials separated for re-use/recycling as an avoided emissions source. Shanks claim that through the re-use and recycling of recovered materials they have avoided the GHG emissions that would have arisen to produce an equivalent quantity of raw materials. However, Shanks do not include as a part of their carbon footprint the GHG emissions associated with the reprocessing of these recovered materials, since this is carried out by a third party; thereby, this activity does not fall within their operational control. Thus, Shanks are claiming the ‘avoided emissions’ reward associated with materials recovery, but are not including the GHG emissions associated with this action.

A further unresolved issue concerns avoided emissions associated with materials recovered for re-use/recycling, namely, how these avoided emissions ‘rewards’ should be distributed and shared if more than one actor is involved in the waste management chain, be it the waste producer, the collector, the materials recovery facility operator, the transporter or the reprocessing facility operator [14]. The EpE Protocol’s current approach, whereby any involved actor may feasibly claim 100% of avoided emissions associated with materials recovery, could easily lead to these avoided emissions being double counted, resulting in an inaccurate portrayal of the waste management sector’s climate change mitigation contribution.

In order to ensure transparency, it is important that waste management companies include as part of their carbon footprint report the methodology they have taken to calculate their avoided emissions. To ensure consistency and accuracy, a standardized approach to the calculation and reporting of avoided emissions that considers all of the aforementioned issues is required.

▪ Reporting

In order for a company to produce a credible, accurate carbon footprint, as a stand-alone figure or as part of an annual report, it is important that they present relevant information in a complete, consistent, accurate and transparent manner [11]. To ensure that the voluntary reporting of GHG emissions by corporations is of a high quality, ISO issued the 14064 series. The GHG Protocol, which is compatible with ISO 14064, provides companies with guidance on what information should be included in a carbon footprint report. The protocol makes the distinction between ‘required’ and ‘optional’ GHG emissions information. For companies to adhere to the GHG Protocol Corporate Standard, they must report, at a minimum, all information deemed ‘required’. Table 5 shows, for each of the seven waste management companies investigated, which ‘required’ information sources are reported. It is clear that the companies are not meeting the basic requirements for carbon footprint reporting. Aside from WRG, who include six of the seven pieces of required information, none of the investigated companies include anywhere close to the essential information required by the GHG Protocol.

The most serious issue concerning carbon footprint reporting practice of the seven largest UK waste management companies concerns the inclusion of details pertaining to emissions sources included in the carbon footprint calculation. At a minimum, it is recommended by both the GHG and EpE Protocols that waste management companies include Scope 1 and 2 emissions in their carbon footprint. However, only three companies (Shanks, Veolia and WRG) report their carbon footprint in a manner coherent enough to determine whether or not all Scope 1 and 2 emissions have been included (Table 5). It is evident that, at present, the reporting of carbon footprints by large UK waste management companies is inadequate for the purpose of informing GHG management strategy and policy.

▪ Verification

Waste management companies may seek verification of the accuracy and completeness of their reported carbon footprint as an assurance to stakeholders. The verification process entails an assessment of a company’s carbon footprint against a pre-established set of GHG accounting and reporting principles. Whilst verification can be undertaken by a company internally, far greater assurances can be provided if a company’s carbon footprint is verified by an external, independent entity [11]. The EpE Protocol considers external verification as being a highly recommended practice, but a nonessential one. The protocol provides waste management companies with minimal guidance on the verification process. Of the waste management companies investigated, none stated that they have their reported carbon footprint verified by an external party. It is possible that many of these companies do have their carbon footprints verified, but simply do not declare this in their carbon footprint reports. There is a need for an authoritative, transparent and trusted verification process, and for specific guidance tailored to the waste management sector.

▪ Small to medium enterprises

Whilst the UK waste management sector is, as previously stated, dominated in terms of revenue by seven large multinational companies, the sector is also characterized by a large number of SMEs. In 2009, there were 2510 VAT- and/or pay-as-you-earn-based UK enterprises engaged in the collection, treatment and disposal of waste. Of these, 1660 (66.1%) reported a turnover of less than £500,000 [10].

SMEs are responsible for approximately 51% of total GHG emissions associated with the waste management sector and, given their dominance in the sector in terms of numbers, it is essential that any future sector-specific protocol takes into account the needs and capabilities of SMEs. Consequently, we recognize that the exclusion of SMEs from this review represents a limitation. The authors of this article acknowledge that current practice and requirements for measuring, reporting and verification of carbon footprints by SMEs may be different from those of large companies.

Conclusion

Whilst large waste management companies have a mandatory requirement to report their GHG emissions under the CRC, beyond this, carbon footprints are predominantly reported voluntarily within the waste management sector. Although the EpE Protocol has been made freely available to waste management companies, its use has been limited. Of the seven companies investigated, three use the EpE methodology (Veolia, Sita and Cory), one uses a variation on the protocol (WRG) and the remaining three companies (Shanks, Biffa and Viridor) use their own in-house methodologies. Thus, of the seven waste management companies investigated, there are as many as five different methodologies being used to measure and report carbon footprint information.

The GHG Protocol lists eight items of ‘required information’ that any organization should include as part of their carbon footprint report. We found that, apart from WRG, who have published the most comprehensive carbon footprint report (including seven of the eight items of required information), the other six companies investigated did not come close to meeting the minimum reporting requirements outlined in the GHG Protocol. The implication of this is that, presently, large waste management companies are not reporting their GHG emissions in a transparent, complete or consistent manner.

Presently, as no commonly agreed sector-specific GHG quantification and reporting standard exists, carbon footprinting has developed into a highly subjective practice in the waste management sector. This subjectivity has resulted in high levels of inconsistency between waste management companies’ carbon footprinting practices. Key aspects of carbon footprinting where inconsistency has been identified include companies’ selection of GHGs, system boundary definition and avoided emissions sources. These issues have resulted in inconsistent, inaccurate, incomplete and incommensurable carbon footprints being published by large waste management companies. Consequently, the carbon footprint information being generated by these companies is ineffective for the purposes it was intended, namely, to act as a tool to guide corporate GHG management. Thus, there is a need for a better quality, consistent, commonly-agreed, waste management sector-specific standard that facilitates accurate measurement, reporting and verification of corporate GHG emissions, and fulfils the ESA’s requirements of being robust, simple and transparent.

▪ Recommendations for a future protocol

While the scope of this article does not extend to detailing precisely how a future waste management sector specific carbon footprinting protocol should be composed, to act as a starting point for discussion we propose the following recommendations: any future protocol must be simple and easy to use whilst simultaneously being accurate and complete; a protocol should stipulate that companies who wish to calculate their carbon footprint measure emissions of CO₂ and CH₄; the most up to date, accurate GWP values should be used, namely, those published in the IPCC’s AR4 [5]; where emissions factors are applied, these must be UK-specific; corporate carbon footprints should be reported for a calendar year to ensure consistency; and emissions of CO_2biogenic should be assigned a GWP of 1 and included in the carbon footprint calculation, although these may be reported separately. Furthermore, several issues must be resolved before a new protocol can be developed: should so-called ‘avoided emissions’ be included and how should these be defined? How should carbon sinks be dealt with? What approach should be adopted in order for companies to define their system boundaries?

Future perspective

The next 10 years will be a period of transition in the UK, as the nation moves towards a low carbon economy. As outlined in The Government Review of Waste Policy in England 2011 [2] and the UK Low Carbon Transition Plan [3], the waste management sector is expected to contribute to the climate change mitigation effort. As such, there is a need for appropriate tools to assist waste management companies and decision makers in developing effective and pragmatic GHG management strategies. These tools must be developed to be robust, accurate and complete, whilst simultaneously retaining high levels of simplicity and usability. Until now, attempts to develop a standardized carbon footprinting tool for the waste management sector have been driven by large, predominantly French, waste management companies. It is now time for waste management companies and the academic community to pool their knowledge and work together to overcome the numerous issues and research challenges concerning carbon footprinting in the waste management sector, many of which have been discussed in this article. Such cooperation would be of enormous benefit to the waste management sector, as it would go further towards the development of effective carbon footprinting tools. Such tools will, ultimately, enhance the sector’s ability to reduce its GHG emissions and contribute to the climate change mitigation effort.

Table 1.  Comparison of different accounting/reporting mechanisms for UK waste management companies.

Accounting/reporting aspect	GHG Protocol	EpE Protocol	PAS 2050 [53]	ISO 14064 Series	Carbon Trust Standard	DEFRA Guidelines	LCA (EASEWASTE)^†
GHG included	Six Kyoto gases^‡	CO2, CH4 and N2O	As listed in AR4 (2007) Table 2.14	Six Kyoto gases^‡	Six Kyoto gases^‡	Six Kyoto gases^‡	User defined
CO2fossil	Yes	Yes	Yes	Yes	Yes	Yes	Yes
CO2biogenic	Reported separately	Reported separately	Yes	Reported separately	Reported separately	Reported separately	Yes
GWP CO2biogenic	0	0	1	0	0	0	0
Cbiogenic sequestration	ND	ND	Yes	ND	ND	ND	Yes
GWP reference	SAR (1995)	SAR (1995)	AR4 (2007)	SAR (1995)	SAR (1995)	SAR (1995)	AR4 (2007)
GWP100 CH4	21	21	25	21	21	21	25
GWP time horizon (years)	100	100	100	100	100	100	User defined (usually 100)
Waste management sector specific	No	Yes	No	No	No	No	Yes
Time boundaries	1 year	1 year	1 year	1 year	1 year	1 year	User defined (usually 1 year)

This table summarizes key aspects and differences between the different procedures but it should be observed that it is by definition an oversimplification of each procedure.

^†A variety of different life cycle assessment tools are available (e.g., WRATE, ORWARE and WISARD) and most parameters are user defined, meaning that there is no single way of undertaking life cycle assessment. For the purposes of this comparison, the life cycle assessment model EASEWASTE was used, as it is an example of a waste-specific tool.

^‡Kyoto gases: CO₂, CH₄, N₂O, HFCs, perfluorocarbons and sulfur hexafluoride.

AR4: IPCC Forth Assessment Report; DEFRA: Department for Environment, Food and Rural Affairs; EpE: Entreprises pour l’Environnement; GWP: Global warming potential; LCA: Life cycle assessment; ND: Not defined; SAR: IPCC Second Assessment Report.

Adapted from [14].

Table 2.  Carbon footprinting methodologies used by the seven largest UK waste management companies in their most recently published corporate social responsibility/environmental performance reports.

Company	Methodology used	Report period	Report used
Biffa Group Ltd	Unknown (not reported)	2009/10 fiscal year	[102]
Cory Environmental Ltd	EpE Protocol GasSim [103] used to calculate emissions from landfill	2008 calendar year	[104]
Shanks Group Plc	Unknown (not reported)	2010/11 fiscal year	[105]
Sita UK Ltd	EpE Protocol	2010 calendar year	[106]
Veolia Environmental Services (UK) Plc	EpE Protocol	2010 calendar year	[107]
Viridor Waste Management Ltd	Unknown (not reported)	2009/10 fiscal year	[108]
Waste Recycling Group Ltd	EpE Protocol (modified)	2009 calendar year	[109]

EpE: Entreprises pour l’Environnement.

Table 3.  GHG selection, global warming potential reference and emissions factors selection of waste management companies investigated.

Company	GHGs included	Global warming potential reference	Emissions factors	Ref.
Biffa Group Ltd	Unknown (not reported); assume CO2, CH4, N2O and SO2	Unknown (not reported)	Unknown (not reported)
Cory Environmental Ltd	CO2, CH4 and N2O	IPCC Second Assessment Report	Unknown (not reported)
Shanks Group Plc	Unknown (not reported); assume CO2 and CH4	Unknown (not reported)	Unknown (not reported)
Sita UK Ltd	CO2, CH4 and N2O	IPCC Second Assessment Report	Unknown (not reported)
Veolia Environmental Services (UK) Plc	CO2, CH4 and N2O	IPCC Second Assessment Report	Veolia Environmental	[110]
Viridor Waste Management Ltd	Unknown (not reported)	Unknown (not reported)	Unknown (not reported)
Waste Recycling Group Ltd	CO2, CH4, N2O and CFCs	IPCC Second Assessment Report	DEFRA emissions factors and default emissions factors from the EpE Protocol	[111]

DEFRA: UK Department for Environment, Food and Rural Affairs; EpE: Entreprises pour l’Environnement.

Table 4.  Avoided emissions sources included in the carbon footprinting calculation of the seven largest UK waste management companies.

Company	Materials separated for re-use/recycling	Renewable energy exports	Waste-derived fuels produced and sold	Renewable energy purchased	Methane emissions avoided by landfill gas combustion
Biffa Group Ltd		✓
Cory Environmental Ltd
Shanks Group Plc	✓	✓	✓
Sita UK Ltd		✓
Veolia Environmental Services (UK) Plc	✓	✓	✓	✓	✓
Viridor Waste Management Ltd		✓
Waste Recycling Group Ltd	✓	✓

Table 5.  Required information according to the GHG Protocol Corporate Standard and, for each of the seven largest UK waste management companies, whether their carbon footprint reports include specified information.

Company	Total (gross) Scope 1 and 2 emissions	Emissions data independently for each Scope	Emissions data for each GHG included (metric tonnes and tonnes of CO2e)	Selected base line year emissions data	Explanation of any historic emission adjustments	Emissions data for CO2biogenic	Carbon footprint calculation methodology used	Details of any exclusions from the calculation
Biffa Group Ltd	✓			✓
Cory Environmental Ltd	✓			✓			✓
Shanks Group Plc	✓	✓		✓				✓
Sita UK Ltd	✓			✓
Veolia Environmental Services (UK) Plc	✓	✓		✓			✓
Viridor Waste Management Ltd
Waste Recycling Group Ltd	✓	✓	✓	✓	✓	✓	✓

Entreprises pour l’Environnement Protocol

Adaptation of the widely used GHG Protocol developed specifically for the waste management sector by the Entreprises pour l’Environnement Association, a group of three large French waste management companies.

Biogenic carbon

Emissions of CO₂ that derive from material of biological origin but excluding fossilized organic matter. Approximately 50% of carbon found in municipal solid waste is of biogenic origin.

Carbon storage

Process for retaining captured CO₂ so that it does not reach the atmosphere; within timescales of centuries or longer.

Operational control

In corporate GHG quantification and reporting, an approach that a company can take to establish its organizational boundaries: “A company has operational control over an operation if the former or one of its subsidiaries has the full authority to introduce and implement its operating policies at the operation”.

Scope 3 emissions

Emissions that occur as a consequence of the operations of a defined population, system or activity but occur externally, either upstream or downstream. Also known as other indirect emissions.

Double counting

An error whereby a transaction or system element is counted twice. For example, a single emission source is accounted twice.

Verification

Independent assessment of the reliability (considering completeness, validity and accuracy) of a GHG inventory. The verification process entails an assessment of a reported carbon footprint against a pre-established set of GHG accounting and reporting principles. Typically, this assessment is undertaken using methods external to the inventory; for example, corporate comparisons with estimates made by other organizations within the relevant sector.

Executive summary

Background

	▪ The waste management sector contributes to approximately 3% of the UK’s GHG emissions. However, certain waste management activities have the potential to reduce the sector’s climatic impacts indirectly; either by generating energy from waste or through the recovery of materials.
	▪ GHG management is becoming increasingly important in the waste management sector and the ‘carbon footprint’ is recognised as a valuable tool to assist GHG management strategy formulation.
	▪ The aim of this paper is to investigate the approaches taken within the UK waste management sector to measure, report and verify its carbon footprint. This aim will be met via critical analysis and evaluation of sector-specific GHG quantification and reporting standards and carbon footprint information reported by the seven largest waste management companies who dominate the sector in terms of revenue share.

Current practice

	▪ Within the waste management sector, large, energy-consumptive companies are obligated under the Carbon Reduction Commitment to calculate and report their GHG emissions. However, the scope of the Carbon Reduction Commitment extends solely to energy-related CO2 emissions.
	▪ In recent years, large waste management companies have begun to voluntarily measure and externally report their operational GHG emissions as a means of demonstrating their commitment to GHG emissions abatement.
	▪ A waste management sector-specific GHG quantification and reporting protocol has been developed, the Entreprises pour l’Environnement (EpE) Protocol, although adoption by waste management companies has been limited. Of the seven companies investigated, there are five different approaches being used to quantify organisational GHG emissions.

Carbon footprinting in the waste management sector: key aspects

	▪ Greenhouse gas selection: There is a lack of consistency between investigated companies’ GHG selection, with several companies failing to report which GHGs they included to calculate their carbon footprint.
	▪ Emissions factors: Emissions factors are used to estimate the amount of GHG emissions associated with a certain activity. The majority of the EpE Protocol calculator’s default emissions factors are based on French studies and, as such, their validity to UK-based companies is questionable.
	▪ Biogenic carbon and carbon sequestration: According to the EpE Protocol, CO2biogenic is assigned a global warming potential of zero, essentially excluding these emissions from the calculation.
	▪ System boundary selection: Presently, the definition of system boundaries in corporate carbon footprinting is highly subjective and the quality of its reporting is poor: only Waste Recycling Group Ltd defined their system boundaries in their carbon footprint report.
	▪ The EpE Protocol’s approach to system boundary definition, the operational control approach, faces several challenges: it is subject to temporal changes that compromise the validity of corporate comparisons; it excludes Scope 3 emissions; it leads to perverse incentives for companies to outsource emissions-intensive activities; and it may lead to double counting.
	▪ Avoided emissions: The EpE Protocol’s approach to allocating avoided emissions “rewards” is highly ambiguous and may lead to double counting. Furthermore, the reporting of avoided emissions sources by investigated companies was found to be highly inconsistent.
	▪ Reporting: Investigated companies failed to meet the basic requirements for carbon footprint reporting as outlined in the GHG Protocol.
	▪ Verification: The EpE Protocol provides insufficient guidance for companies seeking to have their carbon footprints verified by an independent party.

Conclusions

	▪ The reporting of carbon footprint information by large waste management companies is highly inconsistent, incomplete and lacks transparency.
	▪ There is a need for a better quality, consistent, commonly agreed, waste management sector-specific standard that facilitates accurate measurement, reporting and verification of corporate GHG emissions.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.