kg CO₂eq

Definition

• kg CO₂eq is a unit of measurement that expresses the climate impact of greenhouse gases in terms of the equivalent amount of carbon dioxide (CO₂).

• It allows different gases—like methane (CH₄), nitrous oxide (N₂O), and fluorinated gases—to be compared using their Global Warming Potential (GWP) over a standard time frame (usually 100 years).

Purpose and Use

• kg CO₂eq is used to quantify and report emissions in:

  • Carbon footprints

  • Life Cycle Assessments (LCA)

  • Environmental Product Declarations (EPDs)

  • Corporate sustainability reports

• It enables standardized comparisons across products, activities, and organizations.

Calculation Method

• To calculate kg CO₂eq:

  • Multiply the mass of a greenhouse gas by its GWP value.

  • Example: 1 kg of methane (GWP ≈ 27–30) = 27–30 kg CO₂eq.

• The GWP values are defined by the IPCC and vary depending on the time horizon (e.g., 20, 100, or 500 years).

Examples of Emissions

• Everyday activities can be expressed in kg CO₂eq:

  • Driving 1 km in a petrol car ≈ 0.2–0.3 kg CO₂eq.

  • Producing 1 kg of beef ≈ 27 kg CO₂eq.

  • Using 1 kWh of electricity (Italy, 2023 average) ≈ 0.257 kg CO₂eq.

• These values help consumers and companies understand their climate impact.

Importance in Climate Policy

• kg CO₂eq is central to:

  • Carbon accounting and emissions trading

  • Regulatory compliance (e.g., EU ETS, Kyoto Protocol)

  • Sustainability certifications and eco-labels

• It supports climate action planning by identifying high-impact areas and guiding emission reduction strategies.