The global shipping industry plays a vital role in facilitating international trade, with maritime trade experiencing a tenfold increase in value over the past four decades. However, like other transportation sectors such as aviation and automobiles, shipping also contributes to carbon emissions. The International Energy Agency (IEA) predicts a significant reduction in emissions from international shipping in the Announced Pledges Scenario (APS), with estimates suggesting a potential drop of nearly 60% by 2035 and over 90% by 2050. This shift is expected as the industry embraces cleaner fuels like biofuels, ammonia, and methanol, with projections indicating that low-carbon fuels could power more than 80% of global shipping by 2050.
Decarbonizing the shipping industry is essential to meet global emissions targets, and two primary strategies are currently being pursued: enhancing energy efficiency and transitioning to low-emission fuels. These approaches work in tandem to significantly reduce greenhouse gas (GHG) emissions. Enhancing energy efficiency in shipping involves various measures, including “slow steaming” to reduce ship speeds and improve fuel consumption. Additionally, technologies like rigid sails, waste heat recovery, and hull optimization can enhance a vessel’s fuel efficiency and overall performance. New regulations, such as the Carbon Intensity Index (CII), are driving the adoption of energy-saving features in new ships and retrofits, with the aim of achieving substantial efficiency gains by 2030.
While the initial investment for energy-efficient upgrades varies, the long-term benefits in terms of fuel savings can offset these costs. For example, hull form optimization can boost energy efficiency by 7.5%, while more extensive retrofits like kite sails offer smaller gains at a higher price point. Transitioning to low-emission fuels is crucial to further reduce emissions, with options like biodiesel, biomethane, methanol, ammonia, and hydrogen emerging as promising alternatives. These fuels have different cost implications and compatibility with existing ship engines, requiring careful consideration by shipping companies based on factors like vessel size and operational efficiency.
International maritime shipping emissions have been on the rise, reaching a peak in 2023 and accounting for approximately 2% of global energy-related CO2 emissions. Scenarios aligned with the latest International Maritime Organization (IMO) GHG Strategy suggest that emissions could be slashed by more than 90% by 2050 compared to 2023 levels, primarily through the adoption of low-emission fuels like ammonia. As shipping activity is projected to increase, the industry faces the challenge of transitioning to sustainable fuel technologies to meet emission reduction targets.
In a significant development, Danish shipping giant A.P. Moller–Maersk has secured a long-term agreement with China’s LONGi Green Energy Technology Co Ltd to purchase bio-methanol, reinforcing its commitment to zero-emission shipping. This partnership aims to meet Maersk’s sustainability goals by reducing GHG emissions and transitioning to greener fuel sources. The adoption of bio-fuels and e-methanol represents a step towards sustainable shipping practices, although challenges such as cost differentials between fossil fuels and alternative options remain a barrier to widespread adoption.
The transition to low-emission shipping technologies will require substantial investment and regulatory support, but the potential for significant emissions reductions underscores the importance of these efforts for the industry’s sustainable future. As the shipping sector navigates the path towards decarbonization, collaborations and innovations in fuel technologies will be crucial in achieving net-zero emissions and addressing the environmental impact of maritime trade.
Disclaimer: Source of all data and images from IEA Energy Technology Perspective 2024.
