Paris Agreement: Sustainable Shipping and CO2 Reduction
Author: Jeroen Berger • Publication date:
The global shipping industry stands at a crossroads. Like many other sectors, the maritime sector must implement far-reaching changes in sustainability, technological innovation—such as Energy Saving Devices (ESDs), wind-assisted propulsion, and waste heat recovery—and CO2 reduction. While the maritime industry is a vital link in global trade, it must significantly reduce its environmental footprint to meet the objectives of the Paris Agreement—also known as the the Paris Accords or Paris Climate Accords. In this article, we discuss the challenges and sustainable innovations contributing to a greener future for the global shipping sector.
The Climate Challenge: Goals and Approach
The Paris Agreement aims to limit global warming to well below 2°C, with the ambition of keeping it to a maximum of 1.5°C above pre-industrial levels. Participating countries are required to formulate national plans to reduce their greenhouse gas emissions.
The Netherlands translates these international goals into national policy through its Climate Agreement (Klimaatakkoord) and Climate Act (Klimaatwet). The goal is to achieve a 55% reduction in greenhouse gas emissions by 2030 and climate neutrality by 2050.
Until November 2022, the progress was monitored by the Climate Agreement Progress Consultation (Voortgangsoverleg Klimaatakkoord, VGO). This body oversaw monitoring and adjustment of climate targets. After the reduction target was raised to 55% by 2030—aiming for a 60% reduction—the fourth Rutte cabinet (kabinet-Rutte IV) decided on a renewed approach.
Since 2023, the National Climate Platform (Nationaal Klimaat Platform) has taken over this task. This platform promotes collaboration between social organizations, businesses, public authorities, and citizens to accelerate the climate transition. It also ensures transparent monitoring of progress, supported by data from, among others, the Climate and Energy Outlook (Klimaat- en Energieverkenning, KEV) and the Climate Policy Dashboard (Dashboard Klimaatbeleid).
Smart Technologies: The Key to Sustainability
Within the transition to sustainability, the shipping industry plays an important role. Ships are responsible for approximately 3% of global CO2 emissions, underscoring the need to adopt structural measures for greening the sector. Innovations such as alternative fuels, hybrid propulsion, and zero-emission technologies are essential to make shipping more sustainable.
The International Maritime Organization (IMO) aims for a 40% reduction in CO2 emissions per transported unit by 2030 and 70% by 2050, compared to 2008 levels. To achieve these goals, the IMO has introduced two instruments: the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII). The EEXI—applicable only to existing vessels—assesses technical efficiency once based on design features, while the CII measures the annual operational efficiency of both existing and new ships by examining actual CO2 emissions per ton of cargo per nautical mile.
Concrete Shipping Innovations for CO2 Reduction
To meet the objectives of the Paris Agreement, shipowners can equip both existing and newly built vessels with proven innovative techniques. Below are some practical examples that demonstrably contribute to CO2 reduction:
- Energy Saving Devices (ESDs): these devices—such as the Pre-Duct, Pre-Swirl Stator (PSS), Propeller Boss Cap Fin (PBCF), Twisted Rudder, and Rudder Bulb—optimize hydrodynamic propulsion efficiency by reducing resistance and improving propeller performance. This results in lower fuel consumption, fewer emissions, and significant CO2 reduction. For instance, installing a Pre-Swirl Stator on an existing coastal vessel has led to more than 4% fuel savings.
- Wind-Assisted Ship Propulsion Systems (WASP): by using wind power (for example, via suction sails), ships can significantly reduce their dependence on fossil fuels. Practical examples show that installing such systems not only improves fuel efficiency but can also reduce a vessel’s CO2 emissions by up to 40%, contributing to more sustainable shipping solutions.
- Waste Heat Recovery Systems (WHRS): these systems reuse waste heat from exhaust gases and engine cooling water to generate additional energy. This increases energy efficiency, lowers operating costs, and contributes to CO2 reduction. Technologies such as the Organic Rankine Cycle (ORC) have demonstrated improvements in energy efficiency of 6 to 9%, further reducing CO2 emissions.
- Air Lubrication Systems (ALS): by injecting air bubbles underneath the hull, frictional resistance is reduced. This leads to lower fuel costs, improved hydrodynamic efficiency, and a reduction in CO2 emissions. Ships using ALS report fuel savings of 10-20%, resulting in a significant annual CO2 reduction.
- Biocide-Free Antifouling: using biocide-free antifouling on a ship’s hull offers both economic advantages—such as fuel savings—and environmental benefits by cutting CO2 emissions and avoiding chemical pollution. Traditional antifouling products often contain biocides (chemical substances that kill harmful organisms), but these can also negatively affect the environment. Biocide-free antifouling is therefore a more environmentally friendly alternative. Exact savings vary by ship type, sailing behavior, and water conditions, but can be substantial and contribute to a significant reduction in CO2 emissions.
Working Together for a Green Maritime Future
Closer cooperation between governments, shipowners, shipbuilders, suppliers, and technology developers is crucial to speeding up sustainable shipping. Through joint efforts, they can develop innovative technologies and more efficient systems that significantly enhance the environmental performance of shipping. Think of advanced ship designs, alternative fuels like hydrogen and ammonia, and energy-saving technologies such as Energy Saving Devices and wind-assisted ship propulsion systems. Practical tests and simulations using Computational Fluid Dynamics (CFD) can accelerate the development of these sustainable technologies, making them ready for implementation faster.
Financial Incentives for Sustainable Innovations
The government supports companies in the maritime sector in implementing sustainable technologies through subsidies and tax incentives. For example, the Energy Investment Allowance (EIA) makes investments in energy-saving installations—such as systems that reuse waste heat via the Organic Rankine Cycle (ORC)—more financially attractive. In addition, the Environmental Investment Allowance (MIA) and the Random Depreciation of Environmental Investments (VAMIL) offer extra tax benefits for environmentally friendly solutions.
Conclusion: From Innovation to Action
The shipping sector faces a major challenge, but also a unique opportunity to contribute to the global climate goals of the Paris Agreement. By deploying innovative technologies and working together within the maritime sector, ships’ CO2 emissions can be significantly reduced.