Emissions Calculation Background & Methodology. GoZero is a carbon accounting tool that allows companies to accurately calculate, report, and verify their carbon emissions while significantly reducing them.
In today’s world, measuring and reducing your company’s carbon footprint isn’t just a nice-to-have; it is increasingly becoming essential for all businesses. Firstly measuring and then taking steps to minimise carbon emissions can yield significant benefits, from cost savings and improved energy efficiency to enhanced opportunities to tender. Moreover, be- ing a forward-thinking and environmentally conscious business increases customer loyalty, reduces risk and reassures stakeholders of your business’s sustainability.
Carbon Emissions Calculation is often referred to by various terms, such as Greenhouse Gas Accounting, Greenhouse Gas Footprinting, Carbon Accounting, Climate Impact As- sessment, or Environmental Footprint. Each of these phrases emphasizes different dimen- sions of measuring emissions based on the specific objectives of the assessment. Despite the variations in terminology, they all fundamentally address the measurement of carbon emissions and their environmental impact.
Verifying your carbon emissions statements ensures that the data is reliable and credible. This is not only crucial for informed decision-making and strategic planning, but it also gives stakeholders and investors assurance that your organisation is genuinely com- mitted to sustainability. Therefore, third-party carbon footprint validation significantly en- hances your organisation’s reputation in a market where consumers and stakeholders are sceptical of corporate sustainability claims.
For large multinationals, verifying their carbon emissions statements is a regulatory require- ment. Verifying statements helps to avoid accusations of greenwashing – making false or misleading claims about the environmental benefits of a product, service, or company prac- tice – which poses a significant reputational risk to organisations. Verification against a rec- ognised standard, by an independent certification body helps mitigate this risk by providing a transparent and accountable framework for reporting GHG emissions, thus safeguarding your organisation from potential reputational damage and legal repercussions.
ISO 14064-1 is an internationally recognised standard that specifies principles and require- ments for quantification and reporting of greenhouse gas (GHG) emissions and removals and we believe this is the most robust standard available for verifying GHG emissions state- ments.
Our methodology therefore incorporates ISO 14064-1 verification. One of the outputs of the GoZero calculator is an ISO 14064-1 GHG statement. Even more, the GoZero calculator it- self has also been independently verified by a UKAS verification body to ensure that its methodology, data, calculations and outputs meet the ISO 14064-1requirements. Third- party verification is built in as standard because we believe this is critical to the credibility of your claims.
The Intergovernmental Panel on Climate Change (IPCC) publishes com- prehensive guidelines and methodologies for calculating GHG emissions. Their reports, such as the IPCC Guidelines for National Greenhouse Gas
Inventories, are widely used for developing emission factors. The CO2e Emission Factors we use in the GoZero calculator come primarily from the ‘UK Government GHG Conversion Factors for Company Reporting’, Peer-reviewed scientific journals, supplier data, industry groups and organisations developed emission factors tailored to specific processes and technologies and bodies such as the International Energy Agency (IEA) and the United Nations Framework Convention on Climate Change (UN- FCCC). The UK Government recommends using the factors from the calendar year that align with most of your data. For example, if you report data from 01/04/22 – 31/03/23, you would use the 2022 factors. The Calculator version includes the UK Government emission factors from 2020 onwards, up to the current year. Reporting years before 2020 will default to the 2020 emission factors.
Most organisations that calculate their carbon emissions plan to reduce them. The emissions statement identifies the key sources of emissions, and illustrate these clearly with the data to support management decisions. Typically, organisations develop a formal carbon reduction plan: a strategic framework designed to help an organisation reduce its GHG emissions over a specified period. By setting clear goals, implementing targeted re- duction strategies, and continuously monitoring progress, organisations can reduce their emissions, often with the goal of being carbon neutral or reaching net-zero.
The GoZero methodology specifically incorporates the development of a carbon reduction plan. Data from the carbon calculations is used to populate a carbon reduction plan tem- plate, which can then be further developed to incorporate carbon reduction projects. The carbon reduction plan generated for you by GoZero is designed to meet the requirements for common and public procurement requirements in the UK to help with your tendering pro- cess1.
Firstly you will select a Net Zero Target Year, which is your chosen year to reach Net Zero. It should be no later than 2050 and is unlikely to be achieved before 2030. Then you must set your Setting Net Zero Reduction Ambitions. To reach net zero, organisations need to reduce their absolute scope of 1, 2 G 3 emissions by a certain percentage. Please select the level of reduction committed to by the year e.g.,2040 and percentage, such as 60%.
To measure your carbon emissions, we must convert your business activities into CO2e by providing each activity in quantifiable units, such as litres or tonnes—for example, the num- ber of litres of petrol used by company vehicles. Then, we use an Emission Factor containing a mathematical formula, which acts as an intermediary between that activity unit (in this case, litres) and converts it into CO2e, expressed in kg or tonnes. For example, we can use an emission factor to calculate the kilograms of CO2e produced per kilowatt-hour of elec- tricity consumed.
Some examples of carbon emission factors for different types of vehicles are:
The calculations above provide information for reducing emissions, this process is called decarbonisation. It is clear from the above, with no further analysis, that moving from 4*4 vehicles to small vehicles and to electric vehicles produces much lower CO2e.
The GoZero carbon calculator has been specifically designed for use by operational and financial staff in organisations of all sizes who are not carbon accounting professionals. As such it is easy to use, iterative and self-explanatory. The core methodology is a series of calculations with an emission factor generated once a user has input a value for an activity or spend multiplied against a coefficient pulled from an appropriate data source within the calculator (an emission factor usually from a recognised data source, or else a custom factor) generating a product representing part or all of the carbon emission for a particular category. To ensure accuracy and reliability the coefficient source is fully traceable within the tool, and the data source for the user inputted values is also clearly identified, to allow for verification against ISO 14064-1 and similar standards. Uncer- tainty is also reflected in the calculator through assigning data quality grades to inputted information.
The methodology has 3 clear stages:
Every business activity emits greenhouse gases that contribute to global warming. The total greenhouse gas emissions through all the economic activities in your value chain represent your carbon footprint. A carbon footprint is the total amount of greenhouse
gases (GHGs) that a company emits, directly or indirectly, from its opera- tions. These emissions are typically measured in units of carbon dioxide equivalent (CO2e), which allows different types of GHGs to be compared on a like-for-like basis based on their global warming potential. Understanding and managing this footprint is crucial for any business looking to reduce its environmental impact.
Emissions are the greenhouse gases released into the air by the activities performed by your business. The main greenhouse gases are water vapor (H20), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6) ab d they are measured by their concentrations, or parts per million, in the atmosphere.
An ‘activity’ is a process that produces emissions directly or indirectly, expressed as var- ious physical quantities (e.g., mass, volume, energy, distance).
GHG emissions are both direct and indirect emissions. Direct GHG emissions are emissions from sources owned or controlled by the company. Indirect GHG emissions are emissions that are a consequence of the company’s activities but occur at sources owned or controlled by another company.
The various types of emissions are divided into three scopes, 1,2 and 3.
To measure the amount of CO₂ re- leased from a specific ‘activity’, we use something called emissions fac- tors. These factors calculate the av- erage CO₂ output per unit of energy, for example kilograms of CO₂ produced per megawatt-hour (MWh) of electricity purchased from an energy company.
Emissions factors are usually expressed as the weight of the pollutant divided by a spe- cific unit of the activity that causes the pollution, for example, kilograms of particulate matter released per megagram of coal burned.
To get into more detail on a particular activity, let’s take the Scope 3 activity, Employee Commuting. Let’s say this employee commutes in a car, we can calculate the impact of driving in three ways:
All three measurements represent the same activity, but they describe it at different levels of accuracy in relation to carbon emissions calculations.
Therefore:
The more accurate the representation, the more precise our calculations are, underscoring the reliability of the calculations used in our tool. This reliability ensures the security of our process. In this example, the emissions from driving a car are generated by the fuel combustion in the engine, and, with confidence, we can say that the same quantity of fuel produces the same amount of emissions when combusted. Hence, our calculator uses the quantity of fuel consumed to calculate the emissions produced by driving a car.
The GoZero tool allows users to choose their preferred method for defining organisational boundaries. Organisational boundaries typically refer to the operations, facilities, and activities that a company owns or controls, and thus must account for in its carbon reporting. Organisational boundaries help companies determine their direct carbon foot- print. Boundaries are essential for establishing a consistent and transparent scope of carbon accounting, ensuring that all relevant emissions—direct and indirect—are captured.
In carbon footprinting, the operational control and equity share approaches are two methods used to allocate greenhouse gas (GHG) emissions to organisations that share ownership or control of assets, such as a facility or joint venture. Here’s a comparison of the two:
Under this approach, an organisation accounts for 100% of the Green House Gas emissions from operations over which it has control. Control can be defined as either financial control, i.e. the organisation mandates the financial and operating policies of an operation to gain economic benefits. Or operational control, i.e. the organisation has authority to introduce and implement its own operating policies at the facility. In terms of owner- ship, the organisation does not need to own the assets or shares of the entity; it only needs to have control over the operations. Therefore, the company reports all emissions from activities or facilities it controls, even if it does not own them.
This approach provides clear boundaries for reporting emissions.
It aligns well with operational influence, which means companies report emissions over which they have direct control and can reduce. However, it does not reflect the owner- ship structure, so an organisation could report 100% of the emissions from an entity it controls but only partially owns.
The equity share approach allocates emissions based on the percentage of economic interest or ownership an organisation holds in an operation or asset. So, emissions are allocated according to the proportion of equity the organisation owns in a joint venture or partnership. Therefore, the company accounts for emissions in proportion to its share of ownership, whether it controls operations or not.
This method is beneficial as it reflects the company’s economic stake, offering a view of emissions relative to ownership. This is useful for companies with multiple joint ventures, where they may not have full control. However, the equity share approach may lead to fragmented accountability, and the responsibility for decarbonisation might not align with who has the operational ability to reduce emissions. It could also make reporting complex if ownership stakes are constantly changing.
The Operational Control Approach is best used by companies that prioritise reporting emissions over which they have operational control, allowing them to track and manage emissions reductions more effectively. Whereas the Equity Share Approach would be preferable in cases where companies have significant financial investments in joint ventures or partnerships and want to report emissions in line with their economic exposure. The World Resources Institute and the World Business Council for Sustainable Development established these two boundary-setting methodologies and the Greenhouse Gas Protocol recognises both approaches, so companies should choose the one that best fits their structure and reporting goals.
For example, if a company owns 25% of a warehouse, they will report on 25% of that warehouse’s emissions. Using the financial control approach, companies will report on 100% of anything in which they bear the majority of risk and benefit from the operation’s financial performance. A company has financial control over an operation if the operation is included for accounting purposes. When an organisation uses the operational control approach, it will report on everything where it or one of its subsidiaries has complete authority to create and apply operating policies. This is the most typical method for establishing boundaries. It is particularly useful and relevant as it includes all sites where the organisation can influence carbon emissions (for example, changing electricity tariff or installing ground source heat pumps).
The tool allows for both options to be used, although operational control is by far the most common boundary approach adopted by clients. Most companies will adopt the Operational Control approach, meaning any leased assets (buildings, offices, vehicles, etc.) which fall under Scope 1 and Scope 2.If your business has multiple sites or locations or buildings, these should be listed in the tool separately. Each location can have a section of this calculator, allowing you to select locations and compare your emissions across various sites.
This defines which emission sources and activities the organization includes in its reporting based on scopes defined by the Greenhouse Gas Protocol:
To define your reporting boundaries, review each of the emission categories and choose which ones are relevant to your organisation’s activities. This is a crucial step in the re- porting process as it ensures that all relevant emissions are accounted for, providing a comprehensive picture of your organisation’s greenhouse gas emissions.
The GoZero calculator allows you to track your emissions monthly and yearly. Select data from the most recent 12-month period; it is important to select a reporting year that aligns with your company’s financial year. Please choose the latest Reporting Year to ensure the most up to date data. This year will be featured in the automated reports later in the spreadsheet, and it can be updated when new reporting years are completed.
In carbon accounting, a Base Year is a specific year chosen as a reference point for measuring future greenhouse gas (GHG) emissions. Organizations select a base year to establish a benchmark for tracking emissions reductions over time, enabling them to set and monitor progress toward their emissions reduction targets in a consistent and comparable manner.
When deciding on a base year, organizations carefully consider data availability. Typically, they choose a year for which reliable and comprehensive emissions data is accessible. This ensures that the chosen year represents a typical operating cycle, avoiding unusual spikes or drops in emissions, and thereby ensuring accuracy, consistency, and comparability in their carbon accounting efforts.
In some cases, companies may need to modify their base year. For example, suppose a company undergoes mergers, acquisitions, or divestments. In that case, it may need to adjust its base year emissions to maintain consistency. Additionally, companies may re- state their base year emissions if new data becomes available or calculation methods improve.
In summary, a base year is not just a starting point but a crucial foundation for providing a consistent framework for emissions tracking. It plays a key role in helping organizations accurately assess their environmental impact and measure their progress in reducing it, making it an indispensable concept in the field of carbon accounting.
Analyse your business activities and decide which of the emissions categories are relevant to your organisation. The next step is to assign staff to track down the relevant data to feed into the tool.
The GoZero tool calculates corporate carbon footprints using your business data and what’s fed into the tool is information that you, as a business, will already have, and it can be neatly divided into spend-based and activity-based data. To ensure the most accurate calculation, the engine selects the approach depending on the type of data provided by your company. In addition, GoZero can include custom emissions factors that you generate or receive from your suppliers to provide granularity and enhance the quality of the calculations.
GoZero’s carbon calculator quantifies your company’s total GHG emissions by inputting business data for your company’s economic activities and linking the data with an appropriate emission factor coefficient. It does this in accordance with the GHG Protocol requirements for accounting and reporting and identifying and quantifying emissions2. The GHG Protocol requires that companies set appropriate organisational and operational boundaries, and this is done within the GoZero calculator.
Emissions factors are values that quantify the environmental impact of different production processes and are a crucial part of accounting for your greenhouse gases. Emission factors are expressed as the weight of carbon dioxide equivalents (CO₂e) divided by a reference unit, such as the weight, volume, distance, duration, financial unit or even a custom unit unique to the activity or scenario. Emissions factors form the baseline for all carbon footprint calculations and provide an estimate for the raw materials and other activities that a company may not be able to calculate for themselves. The standard emissions conversion factors are necessarily conservative estimates published annually by the UK3 and other governments and estimate the carbon emission intensity based on relevant scientific research, data analysis and modelling. The emission factors are therefore standardised values, based on the amount of greenhouse gas emissions produced per unit of activity or resource consumed. They allow us to estimate the CO₂e emissions associated with various human activities or processes. There are generally three categories of emissions factors: activity, spend or production-based emissions factors, as shown in the table below.
| Emission Factor Type | Example Metric | Primary Data Requirement |
|
Activity-Based |
kg CO₂e per kWh |
Activity data (e.g. electricity or gas usage) |
| Spend-Based | kg CO₂e per pound spent | Financial data (spend) |
| Production-Based | kg CO₂e per unit of output | Production volume |
For example, a toy manufacturer may use a production-based emission factor, to estimate the kg of CO₂e per plastic toy they produce. However, we can work with the company to develop more specific production-based emissions factors, using the primary data provided by companies who take the time to obtain data from their supply chain. Using this more detailed data we can develop intensity ratios which tell us the kg CO₂e per toy produced. As shown in the table, we can also develop activity-based emissions factors for electricity use for example, to calculate the kg of CO₂e per kWh of electricity used in a particular activity, such as lighting the offices. Similarly, we can develop spend- based emissions factors to reveal the kg CO₂e per pound spent by using their financial data.
For example, our toy company, who produce plastic toys would already know how much plastic is used and how it is processed; but we would help that company create an emission factor to calculate the emissions per toy. This production-based emission factor would be calculated by multiplying the standard emission factor with the activity data. You can’t calculate the carbon footprint with only the standard emission factors alone; the plastic manufacturer would also have to pro- vide detailed data from the production process. It’s essential to understand that an emission factor is an estimation calculated based on assumptions and data from studies. Sometimes, the numbers represent the market averages and will differ from the exact plastic-type our toy manufacturer uses. For this reason, developing emission factors with primary data will always improve the accuracy and often reduce the size of carbon footprints.
For the toy company, the primary data would be the specific information from the exact plastic manufacturer that supplies the plastic used to make the toys. We help the toy manufacturer gather this important primary data to improve accuracy and result in a smaller carbon footprint. Therefore, we encourage our clients to include every bit of primary data in your calculations; a process we can assist you with, emission factor by emission factor. The more primary data you can obtain from your supply chain, the more accurate your carbon footprint baseline will be, making it easier to implement carbon reductions.
Almost all organisations use purchased energy, from electricity used to light offices to the gas burned on the stoves in a restaurant. The GoZero calculator uses both location and market-based models and reporting, with one of the two options chosen as the primary reporting method. The GHG Protocol enforces dual reporting because of potential inconsistency and lack of clarity in how electricity emissions were calculated. The Location based method is based on the country your organisation operates in, for example a UK organisation purchases electricity from the UK grid, so the emissions factors are based on this. Alternatively, emissions factors can be based on the factors reported by the particular by the energy provider the organisation uses, for example British Gas. This method allows companies to reap the benefits of their specific green power purchases and contracts, such as renewable energy certificates, which would be lower than estimations based on their location’s grid emissions. When reporting your organisation’s energy usage, we can help you see which method would result in a lower carbon footprint, so you can choose the appropriate reporting method. Regardless of the method you choose, your alternative results will be displayed in the footnotes. In summary:
The quality of activity data has a significant impact on both the reliability and accuracy of carbon calculations and statements. GoZero includes a data grading scale, which both indicates the quality of data on the environmental statement, and provides a driver to improve data quality. Data grading helps standardise evaluations, identify areas for improvement, and track data quality over time.
To maintain high standards of data quality, it’s essential to apply consistent criteria across various data types and keep thorough records of all data sources. Regular re- views of data quality should be conducted to quickly identify and resolve any issues that arise. Setting specific objectives for improving data quality in each reporting cycle is also important.
Furthermore, ensuring that all team members receive proper training in data collection is crucial, as this helps them understand the significance of the grading scale. Leveraging technology can enhance both the accuracy of data and the efficiency of collection. Lastly, it’s important to recognize the limitations of your data, make reasonable assumptions as needed, and transparently communicate these limitations in any reporting tools or calculators used.
GoZero has a structured grading approach of assigning activity data one of four quality levels, shown in the table below.
| Activity Data Criteria | |
| Very Good data quality | Direct measurement data for the reporting period. Reliable primary data for the reporting period. Reliable estimates based on recent operational data. Example: Data obtained from monthly electricity meter readings during the reporting year. Volume or no. of sheets of plywood purchased, confirmed by a material accounts record (Purchase orders, delivery notes and process records). |
| Good data quality | Data derived from financial or operational estimations with a justified method. Verified data partly based on assumptions. Example: Data based on spend on transportation, with adjustments for weight, distance and broad type of vehicle based on actual journeys. |
| Fair data quality | Historical data used with justified adjustments to make them reliable. Estimates with limited direct measurement. Example: Travel data based on two years before the reporting period, extrapolated for 15% growth in employee numbers. Monthly electricity usage based on meter readings from a different but representative site. |
| Basic data quality | Broadly allocated estimates with no direct measurement, high uncertainty, and low direct measurement correlation. Spend-based calculations. Example: Energy use per employee calculated from UK average for sector, with method/justification uncertain. Commuting distance based on averages obtained from Google, with no staff survey or data. |
Precise emissions data is vital for comprehensive GHG reporting and making informed decisions towards achieving net zero. Accurate carbon accounting is the crucial first step on the path to net-zero emissions. With GoZero’s tried, tested and verified calculation methodology, you can swiftly identify significant emissions sources, and gain in- sights that inform your carbon reduction planning.
The GoZero carbon calculator is designed to provide a simple way to calculate carbon emissions, presented in a way that meets the requirements of ISO 14064-1, and allows for verification against that standard. We firmly believe that third-party verification, by a UKAS accredited body, is vital to demonstrate impartiality and avoids accusations of greenwashing.
Inherent within the GoZero calculator is the ability to start simply, with the information and data you have to hand and can obtain from suppliers, landlords etc., and over time increase the detail, accuracy and therefore the reliability of the emissions statements. The GHG Protocol offers a lot of flexibility in how certain processes or situations are handled, and our sustainability and software technicians make strategic choices to ensure maximum accuracy while minimising costs and complexity for your company.
The outputs from using the GoZero calculator will be a formal emissions statement, meeting the requirements of ISO 14064-1; an independent verification statement and ISO 14064-1 certificate by a UKAS accredited body; and a carbon reduction plan fully compliant with UK government requirements.
In today’s world, measuring and reducing your company’s carbon footprint isn’t just a nice-to-have; it is increasingly becoming essential for all businesses. Firstly measuring and then taking steps to minimise carbon emissions can yield significant benefits, from cost savings and improved energy efficiency to enhanced opportunities to tender. Moreover, be- ing a forward-thinking and environmentally conscious business increases customer loyalty, reduces risk and reassures stakeholders of your business’s sustainability.
Carbon Emissions Calculation is often referred to by various terms, such as Greenhouse Gas Accounting, Greenhouse Gas Footprinting, Carbon Accounting, Climate Impact As- sessment, or Environmental Footprint. Each of these phrases emphasizes different dimen- sions of measuring emissions based on the specific objectives of the assessment. Despite the variations in terminology, they all fundamentally address the measurement of carbon emissions and their environmental impact.
Verifying your carbon emissions statements ensures that the data is reliable and credible. This is not only crucial for informed decision-making and strategic planning, but it also gives stakeholders and investors assurance that your organisation is genuinely com- mitted to sustainability. Therefore, third-party carbon footprint validation significantly en- hances your organisation’s reputation in a market where consumers and stakeholders are sceptical of corporate sustainability claims.
For large multinationals, verifying their carbon emissions statements is a regulatory require- ment. Verifying statements helps to avoid accusations of greenwashing – making false or misleading claims about the environmental benefits of a product, service, or company prac- tice – which poses a significant reputational risk to organisations. Verification against a rec- ognised standard, by an independent certification body helps mitigate this risk by providing a transparent and accountable framework for reporting GHG emissions, thus safeguarding your organisation from potential reputational damage and legal repercussions.
ISO 14064-1 is an internationally recognised standard that specifies principles and require- ments for quantification and reporting of greenhouse gas (GHG) emissions and removals and we believe this is the most robust standard available for verifying GHG emissions state- ments.
Our methodology therefore incorporates ISO 14064-1 verification. One of the outputs of the GoZero calculator is an ISO 14064-1 GHG statement. Even more, the GoZero calculator it- self has also been independently verified by a UKAS verification body to ensure that its methodology, data, calculations and outputs meet the ISO 14064-1requirements. Third- party verification is built in as standard because we believe this is critical to the credibility of your claims.
The Intergovernmental Panel on Climate Change (IPCC) publishes com- prehensive guidelines and methodologies for calculating GHG emissions. Their reports, such as the IPCC Guidelines for National Greenhouse Gas
Inventories, are widely used for developing emission factors. The CO2e Emission Factors we use in the GoZero calculator come primarily from the ‘UK Government GHG Conversion Factors for Company Reporting’, Peer-reviewed scientific journals, supplier data, industry groups and organisations developed emission factors tailored to specific processes and technologies and bodies such as the International Energy Agency (IEA) and the United Nations Framework Convention on Climate Change (UN- FCCC). The UK Government recommends using the factors from the calendar year that align with most of your data. For example, if you report data from 01/04/22 – 31/03/23, you would use the 2022 factors. The Calculator version includes the UK Government emission factors from 2020 onwards, up to the current year. Reporting years before 2020 will default to the 2020 emission factors.
Most organisations that calculate their carbon emissions plan to reduce them. The emissions statement identifies the key sources of emissions, and illustrate these clearly with the data to support management decisions. Typically, organisations develop a formal carbon reduction plan: a strategic framework designed to help an organisation reduce its GHG emissions over a specified period. By setting clear goals, implementing targeted re- duction strategies, and continuously monitoring progress, organisations can reduce their emissions, often with the goal of being carbon neutral or reaching net-zero.
The GoZero methodology specifically incorporates the development of a carbon reduction plan. Data from the carbon calculations is used to populate a carbon reduction plan tem- plate, which can then be further developed to incorporate carbon reduction projects. The carbon reduction plan generated for you by GoZero is designed to meet the requirements for common and public procurement requirements in the UK to help with your tendering pro- cess1.
Firstly you will select a Net Zero Target Year, which is your chosen year to reach Net Zero. It should be no later than 2050 and is unlikely to be achieved before 2030. Then you must set your Setting Net Zero Reduction Ambitions. To reach net zero, organisations need to reduce their absolute scope of 1, 2 G 3 emissions by a certain percentage. Please select the level of reduction committed to by the year e.g.,2040 and percentage, such as 60%.
To measure your carbon emissions, we must convert your business activities into CO2e by providing each activity in quantifiable units, such as litres or tonnes—for example, the num- ber of litres of petrol used by company vehicles. Then, we use an Emission Factor containing a mathematical formula, which acts as an intermediary between that activity unit (in this case, litres) and converts it into CO2e, expressed in kg or tonnes. For example, we can use an emission factor to calculate the kilograms of CO2e produced per kilowatt-hour of elec- tricity consumed.
Some examples of carbon emission factors for different types of vehicles are:
The calculations above provide information for reducing emissions, this process is called decarbonisation. It is clear from the above, with no further analysis, that moving from 4*4 vehicles to small vehicles and to electric vehicles produces much lower CO2e.
The GoZero carbon calculator has been specifically designed for use by operational and financial staff in organisations of all sizes who are not carbon accounting professionals. As such it is easy to use, iterative and self-explanatory. The core methodology is a series of calculations with an emission factor generated once a user has input a value for an activity or spend multiplied against a coefficient pulled from an appropriate data source within the calculator (an emission factor usually from a recognised data source, or else a custom factor) generating a product representing part or all of the carbon emission for a particular category. To ensure accuracy and reliability the coefficient source is fully traceable within the tool, and the data source for the user inputted values is also clearly identified, to allow for verification against ISO 14064-1 and similar standards. Uncer- tainty is also reflected in the calculator through assigning data quality grades to inputted information.
The methodology has 3 clear stages:
Every business activity emits greenhouse gases that contribute to global warming. The total greenhouse gas emissions through all the economic activities in your value chain represent your carbon footprint. A carbon footprint is the total amount of greenhouse
gases (GHGs) that a company emits, directly or indirectly, from its opera- tions. These emissions are typically measured in units of carbon dioxide equivalent (CO2e), which allows different types of GHGs to be compared on a like-for-like basis based on their global warming potential. Understanding and managing this footprint is crucial for any business looking to reduce its environmental impact.
Emissions are the greenhouse gases released into the air by the activities performed by your business. The main greenhouse gases are water vapor (H20), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6) ab d they are measured by their concentrations, or parts per million, in the atmosphere.
An ‘activity’ is a process that produces emissions directly or indirectly, expressed as var- ious physical quantities (e.g., mass, volume, energy, distance).
GHG emissions are both direct and indirect emissions. Direct GHG emissions are emissions from sources owned or controlled by the company. Indirect GHG emissions are emissions that are a consequence of the company’s activities but occur at sources owned or controlled by another company.
The various types of emissions are divided into three scopes, 1,2 and 3.
To measure the amount of CO₂ re- leased from a specific ‘activity’, we use something called emissions fac- tors. These factors calculate the av- erage CO₂ output per unit of energy, for example kilograms of CO₂ produced per megawatt-hour (MWh) of electricity purchased from an energy company.
Emissions factors are usually expressed as the weight of the pollutant divided by a spe- cific unit of the activity that causes the pollution, for example, kilograms of particulate matter released per megagram of coal burned.
To get into more detail on a particular activity, let’s take the Scope 3 activity, Employee Commuting. Let’s say this employee commutes in a car, we can calculate the impact of driving in three ways:
All three measurements represent the same activity, but they describe it at different levels of accuracy in relation to carbon emissions calculations.
Therefore:
The more accurate the representation, the more precise our calculations are, underscoring the reliability of the calculations used in our tool. This reliability ensures the security of our process. In this example, the emissions from driving a car are generated by the fuel combustion in the engine, and, with confidence, we can say that the same quantity of fuel produces the same amount of emissions when combusted. Hence, our calculator uses the quantity of fuel consumed to calculate the emissions produced by driving a car.
The GoZero tool allows users to choose their preferred method for defining organisational boundaries. Organisational boundaries typically refer to the operations, facilities, and activities that a company owns or controls, and thus must account for in its carbon reporting. Organisational boundaries help companies determine their direct carbon foot- print. Boundaries are essential for establishing a consistent and transparent scope of carbon accounting, ensuring that all relevant emissions—direct and indirect—are captured.
In carbon footprinting, the operational control and equity share approaches are two methods used to allocate greenhouse gas (GHG) emissions to organisations that share ownership or control of assets, such as a facility or joint venture. Here’s a comparison of the two:
Under this approach, an organisation accounts for 100% of the Green House Gas emissions from operations over which it has control. Control can be defined as either financial control, i.e. the organisation mandates the financial and operating policies of an operation to gain economic benefits. Or operational control, i.e. the organisation has authority to introduce and implement its own operating policies at the facility. In terms of owner- ship, the organisation does not need to own the assets or shares of the entity; it only needs to have control over the operations. Therefore, the company reports all emissions from activities or facilities it controls, even if it does not own them.
This approach provides clear boundaries for reporting emissions.
It aligns well with operational influence, which means companies report emissions over which they have direct control and can reduce. However, it does not reflect the owner- ship structure, so an organisation could report 100% of the emissions from an entity it controls but only partially owns.
The equity share approach allocates emissions based on the percentage of economic interest or ownership an organisation holds in an operation or asset. So, emissions are allocated according to the proportion of equity the organisation owns in a joint venture or partnership. Therefore, the company accounts for emissions in proportion to its share of ownership, whether it controls operations or not.
This method is beneficial as it reflects the company’s economic stake, offering a view of emissions relative to ownership. This is useful for companies with multiple joint ventures, where they may not have full control. However, the equity share approach may lead to fragmented accountability, and the responsibility for decarbonisation might not align with who has the operational ability to reduce emissions. It could also make reporting complex if ownership stakes are constantly changing.
The Operational Control Approach is best used by companies that prioritise reporting emissions over which they have operational control, allowing them to track and manage emissions reductions more effectively. Whereas the Equity Share Approach would be preferable in cases where companies have significant financial investments in joint ventures or partnerships and want to report emissions in line with their economic exposure. The World Resources Institute and the World Business Council for Sustainable Development established these two boundary-setting methodologies and the Greenhouse Gas Protocol recognises both approaches, so companies should choose the one that best fits their structure and reporting goals.
For example, if a company owns 25% of a warehouse, they will report on 25% of that warehouse’s emissions. Using the financial control approach, companies will report on 100% of anything in which they bear the majority of risk and benefit from the operation’s financial performance. A company has financial control over an operation if the operation is included for accounting purposes. When an organisation uses the operational control approach, it will report on everything where it or one of its subsidiaries has complete authority to create and apply operating policies. This is the most typical method for establishing boundaries. It is particularly useful and relevant as it includes all sites where the organisation can influence carbon emissions (for example, changing electricity tariff or installing ground source heat pumps).
The tool allows for both options to be used, although operational control is by far the most common boundary approach adopted by clients. Most companies will adopt the Operational Control approach, meaning any leased assets (buildings, offices, vehicles, etc.) which fall under Scope 1 and Scope 2.If your business has multiple sites or locations or buildings, these should be listed in the tool separately. Each location can have a section of this calculator, allowing you to select locations and compare your emissions across various sites.
This defines which emission sources and activities the organization includes in its reporting based on scopes defined by the Greenhouse Gas Protocol:
To define your reporting boundaries, review each of the emission categories and choose which ones are relevant to your organisation’s activities. This is a crucial step in the re- porting process as it ensures that all relevant emissions are accounted for, providing a comprehensive picture of your organisation’s greenhouse gas emissions.
The GoZero calculator allows you to track your emissions monthly and yearly. Select data from the most recent 12-month period; it is important to select a reporting year that aligns with your company’s financial year. Please choose the latest Reporting Year to ensure the most up to date data. This year will be featured in the automated reports later in the spreadsheet, and it can be updated when new reporting years are completed.
In carbon accounting, a Base Year is a specific year chosen as a reference point for measuring future greenhouse gas (GHG) emissions. Organizations select a base year to establish a benchmark for tracking emissions reductions over time, enabling them to set and monitor progress toward their emissions reduction targets in a consistent and comparable manner.
When deciding on a base year, organizations carefully consider data availability. Typically, they choose a year for which reliable and comprehensive emissions data is accessible. This ensures that the chosen year represents a typical operating cycle, avoiding unusual spikes or drops in emissions, and thereby ensuring accuracy, consistency, and comparability in their carbon accounting efforts.
In some cases, companies may need to modify their base year. For example, suppose a company undergoes mergers, acquisitions, or divestments. In that case, it may need to adjust its base year emissions to maintain consistency. Additionally, companies may re- state their base year emissions if new data becomes available or calculation methods improve.
In summary, a base year is not just a starting point but a crucial foundation for providing a consistent framework for emissions tracking. It plays a key role in helping organizations accurately assess their environmental impact and measure their progress in reducing it, making it an indispensable concept in the field of carbon accounting.
Analyse your business activities and decide which of the emissions categories are relevant to your organisation. The next step is to assign staff to track down the relevant data to feed into the tool.
The GoZero tool calculates corporate carbon footprints using your business data and what’s fed into the tool is information that you, as a business, will already have, and it can be neatly divided into spend-based and activity-based data. To ensure the most accurate calculation, the engine selects the approach depending on the type of data provided by your company. In addition, GoZero can include custom emissions factors that you generate or receive from your suppliers to provide granularity and enhance the quality of the calculations.
GoZero’s carbon calculator quantifies your company’s total GHG emissions by inputting business data for your company’s economic activities and linking the data with an appropriate emission factor coefficient. It does this in accordance with the GHG Protocol requirements for accounting and reporting and identifying and quantifying emissions2. The GHG Protocol requires that companies set appropriate organisational and operational boundaries, and this is done within the GoZero calculator.
Emissions factors are values that quantify the environmental impact of different production processes and are a crucial part of accounting for your greenhouse gases. Emission factors are expressed as the weight of carbon dioxide equivalents (CO₂e) divided by a reference unit, such as the weight, volume, distance, duration, financial unit or even a custom unit unique to the activity or scenario. Emissions factors form the baseline for all carbon footprint calculations and provide an estimate for the raw materials and other activities that a company may not be able to calculate for themselves. The standard emissions conversion factors are necessarily conservative estimates published annually by the UK3 and other governments and estimate the carbon emission intensity based on relevant scientific research, data analysis and modelling. The emission factors are therefore standardised values, based on the amount of greenhouse gas emissions produced per unit of activity or resource consumed. They allow us to estimate the CO₂e emissions associated with various human activities or processes. There are generally three categories of emissions factors: activity, spend or production-based emissions factors, as shown in the table below.
| Emission Factor Type | Example Metric | Primary Data Requirement |
|
Activity-Based |
kg CO₂e per kWh |
Activity data (e.g. electricity or gas usage) |
| Spend-Based | kg CO₂e per pound spent | Financial data (spend) |
| Production-Based | kg CO₂e per unit of output | Production volume |
For example, a toy manufacturer may use a production-based emission factor, to estimate the kg of CO₂e per plastic toy they produce. However, we can work with the company to develop more specific production-based emissions factors, using the primary data provided by companies who take the time to obtain data from their supply chain. Using this more detailed data we can develop intensity ratios which tell us the kg CO₂e per toy produced. As shown in the table, we can also develop activity-based emissions factors for electricity use for example, to calculate the kg of CO₂e per kWh of electricity used in a particular activity, such as lighting the offices. Similarly, we can develop spend- based emissions factors to reveal the kg CO₂e per pound spent by using their financial data.
For example, our toy company, who produce plastic toys would already know how much plastic is used and how it is processed; but we would help that company create an emission factor to calculate the emissions per toy. This production-based emission factor would be calculated by multiplying the standard emission factor with the activity data. You can’t calculate the carbon footprint with only the standard emission factors alone; the plastic manufacturer would also have to pro- vide detailed data from the production process. It’s essential to understand that an emission factor is an estimation calculated based on assumptions and data from studies. Sometimes, the numbers represent the market averages and will differ from the exact plastic-type our toy manufacturer uses. For this reason, developing emission factors with primary data will always improve the accuracy and often reduce the size of carbon footprints.
For the toy company, the primary data would be the specific information from the exact plastic manufacturer that supplies the plastic used to make the toys. We help the toy manufacturer gather this important primary data to improve accuracy and result in a smaller carbon footprint. Therefore, we encourage our clients to include every bit of primary data in your calculations; a process we can assist you with, emission factor by emission factor. The more primary data you can obtain from your supply chain, the more accurate your carbon footprint baseline will be, making it easier to implement carbon reductions.
Almost all organisations use purchased energy, from electricity used to light offices to the gas burned on the stoves in a restaurant. The GoZero calculator uses both location and market-based models and reporting, with one of the two options chosen as the primary reporting method. The GHG Protocol enforces dual reporting because of potential inconsistency and lack of clarity in how electricity emissions were calculated. The Location based method is based on the country your organisation operates in, for example a UK organisation purchases electricity from the UK grid, so the emissions factors are based on this. Alternatively, emissions factors can be based on the factors reported by the particular by the energy provider the organisation uses, for example British Gas. This method allows companies to reap the benefits of their specific green power purchases and contracts, such as renewable energy certificates, which would be lower than estimations based on their location’s grid emissions. When reporting your organisation’s energy usage, we can help you see which method would result in a lower carbon footprint, so you can choose the appropriate reporting method. Regardless of the method you choose, your alternative results will be displayed in the footnotes. In summary:
The quality of activity data has a significant impact on both the reliability and accuracy of carbon calculations and statements. GoZero includes a data grading scale, which both indicates the quality of data on the environmental statement, and provides a driver to improve data quality. Data grading helps standardise evaluations, identify areas for improvement, and track data quality over time.
To maintain high standards of data quality, it’s essential to apply consistent criteria across various data types and keep thorough records of all data sources. Regular re- views of data quality should be conducted to quickly identify and resolve any issues that arise. Setting specific objectives for improving data quality in each reporting cycle is also important.
Furthermore, ensuring that all team members receive proper training in data collection is crucial, as this helps them understand the significance of the grading scale. Leveraging technology can enhance both the accuracy of data and the efficiency of collection. Lastly, it’s important to recognize the limitations of your data, make reasonable assumptions as needed, and transparently communicate these limitations in any reporting tools or calculators used.
GoZero has a structured grading approach of assigning activity data one of four quality levels, shown in the table below.
| Activity Data Criteria | |
| Very Good data quality | Direct measurement data for the reporting period. Reliable primary data for the reporting period. Reliable estimates based on recent operational data. Example: Data obtained from monthly electricity meter readings during the reporting year. Volume or no. of sheets of plywood purchased, confirmed by a material accounts record (Purchase orders, delivery notes and process records). |
| Good data quality | Data derived from financial or operational estimations with a justified method. Verified data partly based on assumptions. Example: Data based on spend on transportation, with adjustments for weight, distance and broad type of vehicle based on actual journeys. |
| Fair data quality | Historical data used with justified adjustments to make them reliable. Estimates with limited direct measurement. Example: Travel data based on two years before the reporting period, extrapolated for 15% growth in employee numbers. Monthly electricity usage based on meter readings from a different but representative site. |
| Basic data quality | Broadly allocated estimates with no direct measurement, high uncertainty, and low direct measurement correlation. Spend-based calculations. Example: Energy use per employee calculated from UK average for sector, with method/justification uncertain. Commuting distance based on averages obtained from Google, with no staff survey or data. |
Precise emissions data is vital for comprehensive GHG reporting and making informed decisions towards achieving net zero. Accurate carbon accounting is the crucial first step on the path to net-zero emissions. With GoZero’s tried, tested and verified calculation methodology, you can swiftly identify significant emissions sources, and gain in- sights that inform your carbon reduction planning.
The GoZero carbon calculator is designed to provide a simple way to calculate carbon emissions, presented in a way that meets the requirements of ISO 14064-1, and allows for verification against that standard. We firmly believe that third-party verification, by a UKAS accredited body, is vital to demonstrate impartiality and avoids accusations of greenwashing.
Inherent within the GoZero calculator is the ability to start simply, with the information and data you have to hand and can obtain from suppliers, landlords etc., and over time increase the detail, accuracy and therefore the reliability of the emissions statements. The GHG Protocol offers a lot of flexibility in how certain processes or situations are handled, and our sustainability and software technicians make strategic choices to ensure maximum accuracy while minimising costs and complexity for your company.
The outputs from using the GoZero calculator will be a formal emissions statement, meeting the requirements of ISO 14064-1; an independent verification statement and ISO 14064-1 certificate by a UKAS accredited body; and a carbon reduction plan fully compliant with UK government requirements.
We take great pride in providing our clients with UKAS-certified carbon reports. Our comprehensive services are designed to assist you in effectively managing reputational risk by offering reliable and precisely measured carbon footprints.