Understanding Life cycle assessment and sustainability criteria terminology

Disclaimer: This interactive graphic aims to provide a simple explanation of typical words and phrases used in the consideration of sustainability criteria and life cycle assessments of alternative marine fuels. However, no representation or warranty, express or implied, is made as to its accuracy or completeness. The terms as defined are in no way to be considered “agreed definitions” from an IMO perspective, and do not imply the expression of any opinion whatsoever on the part of the IMO.

Lifecycle assessment (LCA) framework for alternative marine fuels

Definition of goal and scope

The goal and scope of the assessment is clearly defined

Define the system boundary and functional unit

Lifecycle inventory (LCI) analysis

The “accounting stage” where all input and output data are collected 

Input: Energy and materials consumed, other physical inputs
Output: Waste and pollution, emissions to air, water, and soil, co-products

Lifecycle inventory: Illustrative example

Lifecycle impact assessment (LCIA)

Where the inventory is translated into meaningful results and indicators to assess the environmental impact

  • Selection of sustainability criteria
  • Selection of impact categories and indicators
  • Selection of impact assessment method – For systems with multiple by-products, output allocation could be done by system expansion or co-product allocation
  • LCI result classification to impact categories
  • Calculation of results for impact indicators