Creating a Global Fuel Lifecycle Methodology

Published — January 25, 2023

Executive Summary

The maritime industry wants to decarbonize. With these ambitions comes an increased interest in alternative marine fuels and their ability to deliver reductions in greenhouse gas (GHG) emissions. However, the regulatory landscape surrounding fuels is complex, with different regions of the world adopting different fuel lifecycle methodologies for determining the climate impacts of alternative fuels. These differences yield uncertainty about the actual GHG savings from alternative fuels and may impact crucial decisions as the industry continues to decarbonize.

Harmonizing existing and upcoming fuel lifecycle methodologies into a globally accepted standard for determining climate impact will provide increased certainty and enable ambitious decision-making. We conducted a qualitative assessment of seven existing fuel lifecycle methodologies to learn more about the landscape and harmonization opportunities. Methodologies were selected to reflect regional coverage and the important role they play in regulation and policy. The seven analyzed methodologies were:

  • Roundtable on Sustainable Biomaterials (RSB)
  • Renewable Transport Fuel Obligation (RTFO)
  • Renewable Energy Directive II (RED II)
  • Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)
  • RenovaBio
  • Greenhouse Gas, Regulated Emissions and Energy in Transport (GREET)
  • JEC Well-to-Wheel study

We identified several key trends across the methodologies, including good coverage of biofuels, direct land use change (dLUC), and co-products. However, coverage of fugitive emissions is lacking.There are several notable differences across the methodologies, which must be harmonized in a global methodology. They relate to:

  • Attributional or consequential approaches
  • Handling of dLUC and indirect land use change (iLUC) aspects
  • Co-product allocation
  • Coverage of fugitive emissions.
  • Coverage of marine fuels and system boundaries

The policies that promote alternative fuels mostly focus on the well-to-tank (WTT) part of the fuel lifecycle. From the reviewed studies, only GREET directly addresses alternative maritime fuels from a well-to-wake (WTW) perspective. The other methodologies are relevant to the WTT emissions of maritime fuels.

Most of the reviewed methods follow a core attributional approach, which assesses the direct environmental impact of fuels by accounting for resources and emissions directly related to fuel production and use. Attributional approaches are simpler than consequential approaches, which quantify how emissions change with decisions such as changes in the levels of fuel production.

Infographic: 4 key trends across the methodologies, including Fuel Coverage, Fugitive Emissions, Direct Land Use Change, and Treatment of co-products

Few of the analyzed methodologies use consequential approaches. Still, they are largely considered by academic experts to be preferable for the treatment of emissions from co-products and land use change aspects. Core consequential approaches are likely better suited to supporting strategic decision-making rather than regulations due to the lack of accessible data and the immaturity of the approach.

A global fuel lifecycle methodology needs to balance climate ambitions (depth and breadth of the method) with delivering certainty to the industry. This may require a combination approach, which uses an attributional approach for emissions associated with feedstock, fuel production, and distribution, and a consequential approach for handling co-products.

This will deliver increased certainty on the main GHG emission activities while ensuring that consequential aspects are handled correctly.

A global fuel lifecycle GHG methodology, based on a combination approach similar to PEF and CARB, would provide confidence and certainty on the climate performance of alternative marine fuels. This could play a role in fuel certification and policy-making, unlocking the fuel production capacity needed to decarbonize.