> ## Documentation Index
> Fetch the complete documentation index at: https://docs.maalbar.dk/llms.txt
> Use this file to discover all available pages before exploring further.

# Understanding CO₂eq and Greenhouse Gas Emissions

> Discover why Målbar uses CO₂eq instead of CO₂ alone, and how Global Warming Potential converts all greenhouse gases into one unit.

When Målbar calculates a product's climate impact, the result is expressed in **CO₂eq (carbon dioxide equivalents)** — not just CO₂. This distinction matters because carbon dioxide is only one of several greenhouse gases driving climate change, and using CO₂ alone would undercount a product's true impact.

## Why CO₂ alone is not enough

The atmosphere contains multiple greenhouse gases, each with a different capacity to trap heat. Focusing only on CO₂ ignores significant contributors like methane and nitrous oxide, which are emitted throughout product supply chains — for example, from agriculture, waste decomposition, and industrial processes.

<Info>
  Gases are compared using their **Global Warming Potential (GWP)** — a measure of how much heat a gas traps over a given time period relative to CO₂.
</Info>

## Key greenhouse gases

<CardGroup cols={3}>
  <Card title="Carbon dioxide (CO₂)" icon="cloud">
    The reference gas. GWP = 1. Emitted mainly through combustion of fossil fuels and deforestation.
  </Card>

  <Card title="Methane (CH₄)" icon="fire">
    GWP ≈ **28× CO₂** over 100 years. Emitted from livestock, landfills, natural gas systems, and rice cultivation.
  </Card>

  <Card title="Nitrous oxide (N₂O)" icon="seedling">
    GWP significantly higher than CO₂. Emitted mainly from agricultural soils and fertiliser use.
  </Card>
</CardGroup>

<Note>
  GWP values are based on a 100-year time horizon, as defined by the [GHG Protocol](https://ghgprotocol.org/). Målbar's calculations use the same standard reference values.
</Note>

## How CO₂eq works

By multiplying each gas's emission quantity by its GWP, you convert it into a CO₂-equivalent mass. All gases can then be added together into a single number — CO₂eq — that represents the total climate warming effect of a product's emissions.

**Example:** 1 kg of methane emitted = approximately 28 kg CO₂eq.

This single unit makes it possible to compare climate impacts across different products, materials, and processes on a consistent basis.

## What this means in Målbar

Every climate footprint result you see in Målbar is expressed in kg CO₂eq. This ensures your calculations account for all significant greenhouse gases throughout the product life cycle — giving you an accurate, complete picture of climate impact rather than a partial one.

<Tip>
  When communicating your results externally, specify that figures are in **kg CO₂eq** to make clear you are reporting total climate impact, not just direct CO₂ emissions.
</Tip>

## Download the illustration

<Card title="CO₂eq illustration (PDF)" icon="file-arrow-down" href="https://www.maalbar.dk/wp-content/uploads/2025/07/CO2eq-illustration-VERTICAL.pdf">
  Download the Målbar Academy visual explainer for CO₂eq and greenhouse gas equivalents.
</Card>