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

# 3.3: Life Cycle Assessment & Emissions

> Understand process, embodied, and upstream emissions in carbon removal projects, and how they reduce net carbon output.

<Panel>
  <Card title="Accounting Academy" className="accounting-academy-card">
    <div className="accounting-academy-content">
      <Steps className="my-0">
        <Step title="MODULE 1: Fundamentals" icon="bookmark" iconType="solid" stepNumber={1} titleSize="p">
          * [1.1: Core Concepts & the Data Lifecycle](/accounting-academy/module-1/1-1-core-concepts-data-lifecycle)
          * [1.2: Translating Methodologies to Mangrove](/accounting-academy/module-1/1-2-translating-methodologies-to-mangrove)
          * [1.3: Events and Datapoints](/accounting-academy/module-1/1-3-events-and-datapoints)
          * [Exercise: Design and Build](/accounting-academy/module-1/1-exercise-design-and-build)
        </Step>

        <Step title="MODULE 2: Calculations" icon="bookmark" iconType="solid" stepNumber={2} titleSize="p">
          * [2.1: Calculation Architecture](/accounting-academy/module-2/2-1-calculation-architecture)
          * [2.2: Expanding Your Data Model](/accounting-academy/module-2/2-2-expanding-your-data-model)
          * [Exercise: Multi-Step Calculations](/accounting-academy/module-2/2-exercise-multi-step-calculations)
        </Step>

        <Step title="MODULE 3: Batch Partitioning & LCA" icon="bookmark" iconType="solid" stepNumber={3} titleSize="p">
          * [3.1: What Is a Batch?](/accounting-academy/module-3/3-1-what-is-a-batch)
          * [3.2: Batch Partitioning Strategies](/accounting-academy/module-3/3-2-batch-partitioning)
          * [3.3: Life Cycle Assessment & Emissions](/accounting-academy/module-3/3-3-lca-and-emissions)
          * [3.4: Allocating Emissions to Batches](/accounting-academy/module-3/3-4-allocating-emissions-to-batches)
          * [Exercise: Batch Partitioning & LCA](/accounting-academy/module-3/3-exercise-batch-partitioning-and-lca)
        </Step>

        <Step title="MODULE 4: Mass Balance with Ledgers" icon="bookmark" iconType="solid" stepNumber={4} titleSize="p">
          * [4.1: Introduction to Mass Balance](/accounting-academy/module-4/4-1-intro-to-mass-balance)
          * [4.2: Designing the Ledger Structure](/accounting-academy/module-4/4-2-designing-the-ledger-structure)
          * [4.3: Multiple Batch Types for Different Stages](/accounting-academy/module-4/4-3-multiple-batch-types)
          * [Exercise: Design & Build Mass Balance](/accounting-academy/module-4/4-exercise-design-and-build-mass-balance)
        </Step>

        <Step title="MODULE 5: Integration Testing" icon="bookmark" iconType="solid" stepNumber={5} titleSize="p">
          * [5.1: The Complete Model Assembly](/accounting-academy/module-5/5-1-the-complete-model-assembly)
          * [5.2: Testing Patterns](/accounting-academy/module-5/5-2-testing-patterns)
          * [5.3: Common Integration Pitfalls](/accounting-academy/module-5/5-3-common-integration-pitfalls)
          * [Exercise: Integration Testing](/accounting-academy/module-5/5-exercise-integration-testing)
        </Step>

        <Step title="MODULE 6: Advanced Patterns & Production" icon="bookmark" iconType="solid" stepNumber={6} titleSize="p">
          * [6.1: Model Design Best Practices](/accounting-academy/module-6/6-1-model-design-best-practices)
          * [6.2: Advanced Techniques](/accounting-academy/module-6/6-2-advanced-techniques)
          * [6.3: Production Readiness](/accounting-academy/module-6/6-3-production-readiness)
          * [Exercise: Production Deployment](/accounting-academy/module-6/6-exercise-production-deployment)
        </Step>
      </Steps>
    </div>
  </Card>
</Panel>

<Check>
  **What you'll learn in this lesson:**

  * Identify the three categories of LCA emissions in carbon projects
  * Understand why net carbon removal requires deducting emissions
  * Map emission sources to event types and model inputs
  * Calculate process emissions using emission factors
</Check>

Carbon removal projects don't just remove carbon — they also **produce emissions** in the process. Pyrolysis requires energy, transportation burns fuel, and equipment has embodied carbon from manufacturing. Life Cycle Assessment (LCA) captures all of these emissions so that the reported output is **net** carbon removal, not gross.

```mermaid theme={null}
flowchart LR
    GROSS["Gross Carbon<br/>Removed"] --> NET["Net Carbon<br/>Removed<br/>(tCO2e)"]
    PROC["Process<br/>Emissions"] --> DEDUCT["Total<br/>Deductions"]
    EMB["Embodied<br/>Emissions"] --> DEDUCT
    UP["Upstream<br/>Emissions"] --> DEDUCT
    DEDUCT --> NET

    style GROSS fill:#66bb6a,stroke:#388e3c,stroke-width:2px,color:#000
    style NET fill:#ef5350,stroke:#c62828,stroke-width:2px,color:#000
    style PROC fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
    style EMB fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
    style UP fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
    style DEDUCT fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
```

## Why LCA matters

Without LCA, a project could claim carbon removal without accounting for the carbon it emitted during operations. This would overstate the real climate benefit.

Methodologies require LCA because:

* **Verifiers need it.** Auditors check that reported net removals account for all material emission sources.
* **Registries mandate it.** Standards bodies like Isometric, Puro.earth, and CARB require LCA calculations as part of their quantification methodology.
* **It ensures credibility.** Net carbon figures that account for emissions are defensible and trustworthy in the carbon market.

## The three emission categories

<CardGroup cols={3}>
  <Card icon="fire" title="Process Emissions">
    Energy consumed during production operations.

    * Electricity for pyrolysis
    * Propane/natural gas for heating
    * On-site equipment fuel
    * Water treatment energy
  </Card>

  <Card icon="industry" title="Embodied Emissions">
    Carbon from manufacturing and construction, amortized over the equipment's lifetime.

    * Pyrolysis reactor manufacturing
    * Facility construction
    * Major equipment replacement
    * Typically amortized over 10-20 years
  </Card>

  <Card icon="truck" title="Upstream Emissions">
    Emissions from activities before production begins.

    * Feedstock collection and transport
    * Feedstock processing/preparation
    * Supply chain logistics
    * Raw material extraction
  </Card>
</CardGroup>

<Note>
  Not every project has all three categories. The specific emission sources depend on the project type and methodology. The methodology defines which sources must be included in the LCA boundary.
</Note>

<Tip>
  For projects needing balance tracking and automatic amortization of embodied emissions across batches, see the [Embodied Emissions system ledger](/production-accounting/embodied-emissions) approach.
</Tip>

## Mapping emissions to Mangrove

Each emission source becomes either an **event type** (for variable data) or a **static input** (for fixed factors).

### Event types for emission data

| Event Type         | Example Datapoints                                  | Cadence  |
| ------------------ | --------------------------------------------------- | -------- |
| Energy Consumption | Electricity (kWh), propane (gallons), date range    | Monthly  |
| Transportation     | Distance (km), fuel type, vehicle type, delivery ID | Per-trip |

### Static inputs for emission factors

| Static Input                   | Value | Unit           |
| ------------------------------ | ----- | -------------- |
| Grid emission factor           | 0.417 | kg CO2e/kWh    |
| Propane emission factor        | 5.72  | kg CO2e/gallon |
| Diesel emission factor         | 2.68  | kg CO2e/liter  |
| Embodied emissions (amortized) | 50    | tCO2e/year     |

<Tip>
  Store emission factors as <a href="/production-accounting/data-inputs" target="_blank" rel="noopener noreferrer">static inputs</a>

  in the resource library rather than hardcoding them as constants in the model. This makes it easy to update factors when methodologies change without modifying the model itself.
</Tip>

## Calculating process emissions

Process emissions are the most common LCA component. Here's how each is calculated:

<Steps>
  <Step title="Electricity emissions">
    `electricity_emissions = kWh × grid_emission_factor`

    Example: 10,000 kWh × 0.417 kg/kWh = **4,170 kg CO2e** (4.17 tCO2e)
  </Step>

  <Step title="Propane emissions">
    `propane_emissions = gallons × propane_emission_factor`

    Example: 500 gallons × 5.72 kg/gallon = **2,860 kg CO2e** (2.86 tCO2e)
  </Step>

  <Step title="Transport emissions">
    `transport_emissions = distance × fuel_emission_factor × fuel_consumption_rate`

    Example: 200 km × 0.30 L/km × 2.68 kg/L = **160.8 kg CO2e** (0.16 tCO2e)
  </Step>

  <Step title="Total process emissions">
    `total_process = electricity + propane + transport`

    Example: 4.17 + 2.86 + 0.16 = **7.19 tCO2e**
  </Step>
</Steps>

### Building LCA into your model

In the <a href="/production-accounting/models" target="_blank" rel="noopener noreferrer">Model Editor</a>

, LCA calculations are typically built as a separate branch of the node tree that feeds into a final `difference` node:

```mermaid theme={null}
flowchart TB
    subgraph Carbon["Carbon Calculation"]
        MASS["Biochar Mass"] --> GROSS["Gross Carbon<br/>(tCO2e)"]
        CPCT["Carbon %"] --> GROSS
        F367["3.67"] --> GROSS
    end

    subgraph LCA["LCA Calculation"]
        KWH["Electricity<br/>(kWh)"] --> ELEC["Electricity<br/>Emissions"]
        GEF["Grid Factor"] --> ELEC
        GAL["Propane<br/>(gallons)"] --> PROP["Propane<br/>Emissions"]
        PEF["Propane Factor"] --> PROP
        ELEC --> TOTAL["Total<br/>Emissions"]
        PROP --> TOTAL
    end

    GROSS --> NET["Net Carbon<br/>= Gross - Emissions"]
    TOTAL --> NET

    style MASS fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style CPCT fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style F367 fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style KWH fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style GEF fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style GAL fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style PEF fill:#42a5f5,stroke:#1976d2,stroke-width:2px,color:#000
    style ELEC fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
    style PROP fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
    style TOTAL fill:#ffa726,stroke:#f57c00,stroke-width:2px,color:#000
    style GROSS fill:#66bb6a,stroke:#388e3c,stroke-width:2px,color:#000
    style NET fill:#ef5350,stroke:#c62828,stroke-width:2px,color:#000
```

***

### Check your understanding

<Accordion icon="circle-question" title="What are the 3 categories of LCA emissions in carbon removal projects?">
  **Process emissions** (energy consumed during operations), **embodied emissions** (manufacturing and construction, amortized over equipment lifetime), and **upstream emissions** (feedstock collection, transport, and pre-processing). The methodology defines which sources must be included.
</Accordion>

<Accordion icon="circle-question" title="Why should emission factors be stored as static inputs rather than constants?">
  Static inputs can be updated in the resource library **without modifying the model**. When a methodology updates its emission factors (e.g., a new grid emission factor), you only need to change the static input value — all future batch calculations automatically use the new factor. Constants hardcoded in the model require a model edit and new version.
</Accordion>

***

Next, learn how to allocate shared emissions across individual batches in [Lesson 3.4: Allocating Emissions to Batches](/accounting-academy/module-3/3-4-allocating-emissions-to-batches).