A literature review on decarbonization pathways and operational strategies for sustainable shipping

Alaa Ammar, Thandeka Tembe

Abstract


International shipping represents 2% to 3% of worldwide greenhouse gas (GHG) emissions. It is being regulated more to meet international climate strategies. The International Maritime Organization (IMO) 2023 Revised Strategy targets net-zero GHG emissions for international shipping by 2050. Meeting this target will require operational, fuel type, and policy changes.

This study focuses on measures to operationalize decarbonization and on strategies for greater sustainability in shipping. The operational measures, alternative fuels, and policy approaches are examined through a systematic literature review of peer-reviewed literature (most current is 2025), compliant with PRISMA 2020, from 2015-2025. The literature describes operational efficiency, the role of digitalization and coordination between ships and ports, the life cycle, or 'well to wake,' of alternative marine fuels, and current and developing policies and regulations.

Operational measures will yield positive results and demonstrate the benefits of subsequent approaches but will not achieve full or deep decarbonization. Long-lasting, or permanent, solutions will be economically unachievable without the use of zero- or near-zero-carbon fuels. The alternative to economically unachievable permanent solutions is the use of ammonia, methanol, hydrogen, and synthetic fuels, but their life-cycle impact must be addressed. The review also recognizes the value of market-based measures.

The policy recommendations, operational measures, and fuel-type changes should include the integrated life-cycle approaches. This study will serve to define future research on operational measures and strategies for the essential sustainability of shipping.

 

Received: 10 March 2026

Accepted: 18 April 2026

Published: 01 June 2026


Keywords


Maritime decarbonization, Sustainable shipping, Operational efficiency, Alternative marine fuels, IMO GHG strategy.

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References


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DOI: https://dx.doi.org/10.21622/MACI.2026.03.1.1994

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Copyright (c) 2026 Alaa Ammar, Thandeka Tembe

Multidisciplinary Adaptive Climate Insights

E-ISSN: 3009-6332

P-ISSN: 3009-7924

 

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