Carbon Accounting

When we talk about CO₂ emissions, we refer to the amount of carbon dioxide released into the atmosphere as a result of the combustion of fossil fuels, coal, oil, and other raw materials. However, CO₂ is not the only greenhouse gas: other significant GHGs include methane (CH₄), nitrous oxide (N₂O), and fluorinated gases. These gases significantly contribute to global warming and have a much higher heat-trapping capacity than CO₂.

In addition to CO₂, other greenhouse gases that impact the climate include:

• Methane (CH₄): Primarily emitted from agricultural activities and decomposition processes in waste.
• Protossido di azoto (N₂O): Emesso dall’uso di fertilizzanti in agricoltura e da alcune attività industriali.
• Gas fluorurati: Utilizzati principalmente nei processi industriali e come refrigeranti, hanno un potere di riscaldamento globale molto elevato.

The unit of measurement for GHG emissions is CO₂eq (CO₂ equivalent). This parameter normalizes the impact of different greenhouse gases in terms of “Global Warming Potential” (GWP), allowing all emissions to be expressed in a single unit. Each greenhouse gas has a different GWP; for example, methane (CH₄) has a warming potential approximately 25 times greater than CO₂.

GHG emissions can be measured directly at the source using specific monitoring equipment or indirectly through the application of emission factors. These factors are coefficients that determine GHG emissions per unit of activity (e.g., per quantity of fuel consumed or per kilometer traveled). Emission factors are applied to specific categories of emission sources, such as fuel combustion or industrial processes.

Scope 1 (direct emissions) and Scope 2 (indirect emissions from purchased energy) emissions can be calculated by collecting activity data for Scope 1 and energy consumption data for Scope 2. These data points are then multiplied by their respective emission factors, which are coefficients that define emissions per unit of activity or energy consumed.

Scope 3 emissions (indirect emissions along the value chain) can be calculated using three main methodologies, each with a different level of accuracy:

1. Activity-based methodology: Involves collecting specific data on business activities and applying detailed emission factors.
2. Economic Methodology: Based on the use of economic data, such as expenses, to estimate emissions using sectoral averages.
3. Screening Methodology: A preliminary-level methodology that uses low-detail data to provide an initial estimate of emissions.

The GHG Protocol, the world's most widely used framework for GHG emissions accounting, classifies emissions into three categories: Scope 1, Scope 2, and Scope 3.

1. Scope 1: Represents direct emissions, meaning those generated directly by business activities, such as fuel combustion in boilers, vehicles, or other industrial processes.
2. Scope 2: Includes indirect emissions related to energy purchased by the company, such as electricity, heating, or cooling. Although these emissions are not directly generated by the organization, it is responsible for them as it consumes these resources.
3. Scope 3: Refers to indirect emissions along the value chain, which include all other emissions related to the organization's activities but occurring outside its direct control. Examples include emissions from the production of purchased goods and services, transportation, and waste management.

The classification of emissions into Scope 1, 2, and 3 is essential for helping companies understand the full lifecycle of their greenhouse gas emissions and implement effective measures to reduce them. In particular, Scope 3 emissions often represent the most significant and complex portion to manage, as they involve external actors beyond the company.