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Life Cycle Assessment (LCA) is the scientific methodology behind environmental footprinting. This guide explains the core principles of LCA in simple terms to help you understand how GREENZERO Journey calculates environmental impacts.

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What is Life Cycle Assessment?

Life Cycle Assessment (LCA) is a structured, comprehensive method to evaluate the environmental impacts of a product or service throughout its entire life cycle—from raw material extraction to end-of-life disposal or recycling.
Think of LCA as an environmental accounting system that tracks all the “environmental costs” of a product, just as financial accounting tracks monetary costs.

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The Four Phases of LCA

According to ISO 14040 and 14044 (the international standards for LCA), a proper LCA consists of four distinct phases:
1

Goal and Scope Definition

Determining what you’re studying and why. This includes: - Purpose: Why you’re conducting the LCA - Functional Unit: The specific unit of analysis (e.g., “one t-shirt worn 50 times”)
  • System Boundaries: Which life cycle stages are included - Impact Categories: Which environmental impacts you’ll measure
GREENZERO Journey automatically sets appropriate system boundaries and includes eight key impact categories for comprehensive assessment.
2

Life Cycle Inventory (LCI)

Collecting data on all inputs and outputs for each process in the product system: - Inputs: Raw materials, energy, water, land - Outputs: Emissions to air, water, and soil; waste This is where your Bill of Materials (BOM) plays a crucial role—it provides the foundation for the inventory analysis.
GREENZERO Journey’s AI matches your materials to its database of environmental profiles, automating the most data-intensive part of LCA.
3

Life Cycle Impact Assessment (LCIA)

Converting inventory data into potential environmental impacts: 1. Classification: Assigning inventory results to impact categories 2. Characterization: Converting results to common units within each category 3. Normalization: (Optional) Comparing results to reference values 4. Weighting: (Optional) Applying value-based weights to different impacts
GREENZERO Journey handles all these calculations automatically and presents results in both scientific units and monetized environmental costs.
4

Interpretation

Analyzing results to identify significant issues, evaluate completeness and consistency, and draw conclusions: - Hotspot Analysis: Identifying major contributors to impacts - Sensitivity Analysis: Testing how changes affect results - Uncertainty Analysis: Understanding the reliability of results - Conclusions and Recommendations: Determining actions based on findings
GREENZERO Journey provides visual interpretations and highlights hotspots to help you understand where to focus improvement efforts.

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Key LCA Concepts for Beginners

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System Boundaries

System boundaries define which processes are included in your LCA. Common approaches include:
  • Cradle-to-Grave
  • Cradle-to-Gate
  • Gate-to-Gate
  • Cradle-to-Cradle
The complete life cycle from raw material extraction through disposal. When to use: For comprehensive understanding of total environmental impacts.
GREENZERO Journey typically uses a cradle-to-gate approach by default, as this covers the phases most companies have direct influence over. The system can be expanded to include use and end-of-life phases when relevant data is available.

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Functional Unit

The functional unit is the reference unit for which environmental impacts are calculated. It defines:
  1. What the product does (function)
  2. How much of that function is provided (quantity)
  3. How well it performs (quality)
  4. For how long it provides that function (duration)
Examples of functional units:
  • “Wearing a t-shirt for one day”
  • “Packaging and preserving 1 liter of beverage for 6 months”
  • “Providing illumination of 800 lumens for 10,000 hours”
A well-defined functional unit ensures fair comparisons between different products that serve the same function. For example, comparing a plastic bottle to a glass bottle should be based on the same volume of beverage packaged.

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Allocation

Allocation is the process of dividing environmental impacts between multiple products from the same process. For example:
  • How to divide impacts between milk and leather from dairy farming
  • How to assign impacts to main products versus by-products
  • How to handle recycling between product systems
GREENZERO Journey handles allocation automatically using standard methodologies, but you can adjust these settings for specific cases if needed.

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Data Quality

The reliability of LCA results depends heavily on data quality. Key considerations include:
  • Primary vs. Secondary Data: Direct measurements vs. database values
  • Temporal Relevance: How recent the data is
  • Geographic Relevance: Whether data represents the correct region
  • Technological Relevance: Whether data represents the correct processes
GREENZERO Journey uses the most appropriate data available and clearly indicates data quality and uncertainty in results.

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How GREENZERO Journey Simplifies LCA

Traditional LCA requires specialized expertise, extensive data collection, and complex calculations. GREENZERO Journey makes LCA accessible by:

Automated Data Collection

AI extracts product information from descriptions, websites, or files.

Built-in Environmental Database

Access to thousands of materials and their environmental profiles.

Standardized Methodology

Consistent application of ISO 14040/44 principles.

Visual Results

Clear visualization of impacts and hotspots.

Transparent Calculations

Full visibility into how results are calculated.

Improvement Recommendations

Actionable suggestions to reduce environmental impacts.

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Common LCA Limitations to Be Aware Of

While LCA is a powerful tool, it’s important to understand its limitations:
  1. Data Uncertainty: Environmental data often has inherent uncertainty
  2. Methodological Choices: Different methodological choices can lead to different results
  3. Temporal Limitations: LCA provides a snapshot in time and may not reflect future changes
  4. Geographic Generalization: Data may not perfectly represent specific locations
  5. Impact Coverage: Not all environmental impacts can be quantified
GREENZERO Journey addresses these limitations through transparent reporting of data quality, clear methodology documentation, and continuous updates to its environmental database.

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Next Steps

Now that you understand the basics of LCA, you’re ready to:
  1. Learn how to conduct Your First Environmental Assessment
  2. Understand how to Interpret Results
  3. Explore Common Questions about environmental footprinting
Remember that GREENZERO Journey handles the technical complexities of LCA for you. You don’t need to be an LCA expert to get valuable insights from the platform.
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