Understanding Life cycle assessment and sustainability criteria terminology

Disclaimer: This list of relevant terms 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, as agreed by members of the Global Industry Alliance to Support Low Carbon Shipping (Low Carbon GIA). However, no representation or warranty, express or implied, is made as to its accuracy or completeness. It is a non-exhaustive list and the terms as explained 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. For definitions, refer to ISO 14040/44 as appropriate.

The figure below has been modified from ISO 14040.

Life cycle assessment (LCA) framework for alternative marine fuels

Goal and scope definition

The goal and scope of the assessment is clearly defined

  • Define the system boundary and functional unit
  • Define the life cycle inventory modelling framework and handling of multifunctional processes – this could be solved using subdivision of unit process, system expansion or allocation
  • Selection of sustainability criteria
  • Selection of impact categories and impact indicators

Life cycle 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

Life cycle inventory: Illustrative example

Life cycle impact assessment (LCIA)

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

  • Selection of impact assessment method
  • Conversion of LCI results into impacts
  • Calculation of results for impact indicators