🏭 Scope 1 emissions explained in detail
Scope 1 emissions represent the direct greenhouse gas emissions from sources that an organization owns or controls, making them a critical component of a comprehensive greenhouse gas inventory. These emissions arise from various activities, including fuel combustion for energy generation, industrial processes, and agricultural practices. Organizations can identify their Scope 1 sources by following guidelines from the IPCC, which classifies emissions into specific categories. Accurate calculation of these emissions involves using activity data and emission factors, with methodologies ranging from simple estimates to complex, technology-specific calculations. By effectively tracking and reporting Scope 1 emissions, organizations can take significant steps toward reducing their overall environmental impact.
What are Scope 1 emissions?
Scope 1 emissions are direct greenhouse gas emissions from sources owned or controlled by an organisation. Because the organisation owns these emission sources, it has high control and ability to reduce or mitigate emissions. Tracking and reporting Scope 1 emissions is a key part of an organisation's overall greenhouse gas inventory.
How to identify Scope 1 emission sources?
The most straightforward and efficient method for identifying sources is to work collaboratively with various operating departments and provide them with a list of greenhouse gases that need to be considered for reporting. However, if you wish to prepare yourself and your teams ahead of time and require a comprehensive framework, you can refer to the IPCC guidelines. The IPCC offers a structured approach that categorizes and defines emission sources into distinct categories and subcategories. Although these guidelines are primarily intended for national GHG inventory reporting, organizations can also utilize the same framework to find out their own Scope 1 sources.
Below are common Scope 1 emitting activities and the typical greenhouse gases they emit. Organisations can use this list to identify their own Scope 1 sources. When reporting Scope 1 emissions, each greenhouse gas is multiplied by its global warming potential (GWP, 100 years) taken from IPCC assessment report. The emissions are reported in t-CO2e (tonne-CO2 equivalent).
| Category | Source Activity | Greenhouse Gas |
|---|---|---|
| Energy related | ||
| Fuel combustion activities |
Emissions from when materials are intentionally burnt in a device that
generates
heat, which can then be used either for heating purposes or to perform
mechanical
work in a process. This includes emissions due to
|
CO2, CH4, N20 |
| Fugitive emissions from fuels |
Includes all intentional or unintentional release of greenhouse gases
during the
extraction, processing, storage and delivery of fossil fuels. This
includes
emissions due to
|
CO2, CH4, N20 |
| Industrial processes and product use | ||
| Process Emissions in Mineral Industry, Chemical Industry, Metal Industry, and Electronics Industry | Emissions from industrial processes and product use, excluding those related to energy combustion, extraction, processing and transport of fuels. | CO2, CH4, N2O, HFCs, PFCs, SF6 |
| Emissions from using non-energy products made from fuels | The use of oil products and coal-derived oils primarily intended for purposes other than combustion. This includes emissions from lubricants and paraffin waxes oxidised during the use phase. | CO2, CH4, N2O |
| Fugitive emissions from using fluorinated gases as substitute of ozone depleting substances |
This includes fugitive emissions during manufacturing, use and disposal
of
|
CO2, CH4, N2O |
| Fugitive emission from other product uses |
This source covers evaporative emissions of nitrous oxide arising from
|
N2O |
| Emissions from agriculture and land use | ||
| Emissions from livestock |
|
CH4, N2O |
| Emission from other agricultural activities |
|
CO2, CH4, N2O |
| Emissions from settlements | Emissions and removals from all developed land, including transportation infrastructure and human settlements of any size, unless they are already included under other categories. This should be consistent with national definitions. | CO2 |
| Emission from waste | ||
| Emissions from wastewater treatment and discharge | Anaerobic decomposition of organic matter by bacteria in sewage facilities and from food processing and other industrial facilities during wastewater treatment. N2O is produced by bacteria in wastewater treatment and discharge. | CH4, N2O |
| Emissions from solid waste disposal |
|
CO2, CH4, N2O |
How to calculate Scope 1 emissions?
Calculating Scope 1 emissions typically involves using emission factors. The basic equation is: Emissions = Activity Data x Emission Factor.
Activity data refers to operational data collected from the business, like the amount of fuel burned. This is multiplied by an emission factor, which is a ratio relating emissions to activity levels for a given source. For example, a coal power plant would track the tons of coal burned and multiply this by an emission factor in tons of CO2e per ton of coal consumed.
Emission factors represent the average emissions from a specific process or source. They are influenced by technology, operating conditions, and other variables. As a result, emission factors for the same process can differ by location. Emission factors are also updated over time as measurement techniques improve and industry practices change. Using localised, current emission factors leads to more accurate Scope 1 inventory calculations.
What are the tier-based methods for calculating Scope 1 greenhouse gas emissions?
Greenhouse gas inventories often use tier-based methods to calculate emissions. The tiers represent increasing levels of complexity. Typically, Tier 1 is the simplest, while higher tiers are more complex. Inventory compilers match the tier level to the available data, resources, and desired accuracy. More complex tiers provide greater accuracy but require more data and resources.
The tier-based system for calculating emissions can be better understood with an example. At the most basic Tier 1 level, default emission factors based on general assumptions are used to estimate emissions from fuel combustion. Tier 2 improves on this by utilising country-specific emission factors that account for national fuel characteristics. More advanced tier methods utilize technology-specific emission factors, which means they take into account detailed information about the specific technologies used in combustion devices. This approach involves analyzing various aspects, such as the type of equipment, efficiency ratings, and operational practices. This tiered approach provides flexibility - simpler Tier 1 factors may suffice in some cases, while higher tiers yield the most accurate, customised estimates for major sources when justified. Overall, the tier framework allows methodology to be matched to the organisation's needs and capabilities.
Emissions can be calculated using mass balance or stoichiometry also. Mass balance is often used to estimate emissions in agriculture and forestry. Emissions can also be directly measured.
Where can I find Scope 1 emission calculation methodology?
The Greenhouse Gas (GHG) Protocol provides various calculation tools designed to assist organizations in measuring their greenhouse gas emissions. In addition, the Intergovernmental Panel on Climate Change (IPCC) guidelines offer a comprehensive framework for conducting emissions calculations. Organizations can utilize these resources or collaborate with experts in the field to ensure accurate assessments. During the verification process, it is essential for organizations to maintain a clear audit trail. This should include detailed records of activity data, the emission factors applied, and any other pertinent information. It is crucial that the calculations are characterized by accuracy, transparency, consistency, relevance, and completeness. While the GHG Protocol and ISO standards do not mandate specific calculation methodologies, they provide flexibility for organizations to choose approaches that best suit their needs.
Calculating emissions under a GHG program
Greenhouse gas (GHG) programs aim to track, verify, trade, or regulate GHG emissions globally, nationally or locally. Cap-and-trade programs, emissions trading programs or registries are common types of GHG programs. Some GHG programs have legal authority. Companies reporting under a program must use the calculation methodology the program defines. For instance, Australia's National Greenhouse and Energy Reporting Scheme is a GHG program. Companies covered under this program must follow the calculation methodology outlined in the NGER Determination (Measurement) , a legislative instrument.
Data collection
Accurate data collection is crucial for developing a comprehensive greenhouse gas inventory. Organisations typically gather two types of data to calculate emissions: activity data and emission factors. Activity data comes from facility, metre readings, procurement records, accounting information, invoices, or supplier data. Emission factors are derived from peer-reviewed, documented sources. Continuously improving data quality is essential. Assess data against quality indicators like temporal representation, geographic coverage, technological representation, completeness, and reliability. Implement data collection practices that enhance the data sets used in the inventory over time.