A roadmap towards eliminating greenhouse gas emissions and air pollutants of the inland navigation sector by 2050 - How to adress the related economic, financial, technical and regulatory obstacles?

The Central Commission for the Navigation of the Rhine (CCNR) is an intergovernmental organization that exercises an essential regulatory role in the navigation of the Rhine. It is active in the technical, legal, economic and environmental fields. In all its areas of action, its work is guided by the efficiency of transport on the Rhine, safety, social considerations, and respect for the environment. Many of the CCNR’s activities now reach beyond the Rhine and are directly concerned with European navigable waterways more generally.



Addressing the issue of climate change is a political priority both nationally and internationally. The Paris Agreement (2015), which aims to slow the pace of climate change (maximum 2 °C increase) by reducing greenhouse gases (GHG) emissions is one of its key components.

In the Declaration signed in Mannheim on 17 October 2018, the inland navigation Ministers of the Member States of the CCNR (Germany, Belgium, France, Netherlands, Switzerland) reasserted the objective of largely eliminating GHG and other pollutants by 2050, a long-term vision which is also shared by the European Union (EU).

In addition, to further improve the environmental sustainability of navigation on the Rhine and inland waterways, the same Mannheim Declaration tasked the CCNR to develop a roadmap for:

  • reducing GHG emissions by 35% compared with 2015 by 2035,
  • reducing pollutant emissions by at least 35% compared with 2015 by 2035,
  • largely eliminating GHG and other pollutants by 2050.

This energy transition must be seen as a crucial challenge for Rhine and European inland navigation. Based on today’s knowledge, while innovations to reduce emissions from existing vessels and newbuilds have increased in recent years, they tend for the time being to be limited to pilot projects, which are however of utmost importance in gaining knowledge about new technologies, and addressing economic, financial, technical and regulatory obstacles to the deployment of relevant technologies.

Despite current uncertainties concerning especially the development, the cost, the level of maturity and the availability of the technologies contributing to the transition towards a zero-emission inland navigation sector, it is necessary to immediately start designing an approach towards this ambitious objective that can be sustained in the medium and long-term.

In this context, identifying and considering the measures enabling an accelerated transition towards zero-emissions (such as regulatory measures, emissions monitoring, financial support for the energy transition, …), together with the development of technology transition pathways for the fleet, are essential elements to be included when designing a realistic and sound roadmap.

In today’s circumstances, air pollutants can be reduced to a large extent with internal combustion engines (ICE) equipped with modern aftertreatment, while the reduction of GHG emissions remains the most challenging part. Beyond the use of new energy carriers (like methanol or hydrogen) in combination with energy converters (like fuel cells or ICE), reduction of energy consumption by all possible means is an important lever to achieve the emission reduction objectives. This includes for example better use of vessels, increased efficiency by means of modern propulsion systems, the improvement of vessels’ hydrodynamics, smart navigation with less waiting time at locks, and efficient integration of inland navigation into seaports logistics.

Wherever possible, careful attention should be paid to developments in other modes of transport, such as road, rail and short-sea shipping. Indeed, there is much to be learned from the experience gained by other modes regarding the energy transition.

Last but not least, the relatively small size of the European inland waterway vessel market implies that technological solutions designed specifically for the inland navigation sector alone might not be commercially viable. It is therefore unlikely that a technological solution will be developed for the inland waterway transport sector alone. From this perspective, synergies should be found with technologies developed for seagoing vessels and for non-marine applications whether in Europe or in other parts of the world.

In light of the above, largely eliminating both GHG and air pollutant emissions from inland navigation by 2050 is clearly no longer an option but a necessity if inland navigation wants to preserve and strengthen its position as a competitive, sustainable and environmentally friendly mode of transport. In other words, the fleet modernisation and the energy transition are motivated by addressing climate change with reduction of GHG emissions, reducing health-related risks by improving air quality but also reducing the sector’s operational costs (OPEX) by increasing efficiency of inland navigation.



The recently adopted roadmap aims primarily to deliver on the mandate conferred by the Mannheim Declaration in 2018 and to help address the crucial challenge of the energy transition for Rhine and European inland navigation.

Built on the CCNR study on the energy transition towards a zero-emissions inland navigation sector (CCNR, 2021), the roadmap should be understood as the primary CCNR instrument for climate change mitigation and for giving effect to the energy transition. The objective is to reduce Rhine and inland navigation emissions by:

  • setting transition pathways for the fleet (new and existing vessels),
  • suggesting, planning, and implementing measures directly adopted or not by the CCNR,
  • monitoring intermediate and final goals set by the Mannheim Declaration.

It goes without saying that many players will be involved in this energy transition, such as vessel owners, operators, shippers, and shipbuilders as well as representatives of the sector, classification societies, equipment manufacturers, infrastructure operators, service and energy providers, universities or research institutes, the scientific community with relevant organizations such as PIANC, international organisations including European Union institutions and river commissions (Moselle Commission, Danube Commission, International Sava River Basin Commission), the CCNR, and national administrations of European States with inland waterways.

The CCNR hopes with its roadmap to contribute to the development of a shared vision of the energy transition and associated challenges within the European inland navigation sector, while also generating support and acceptance for related policy measures.



To ensure a common understanding between all the actors involved in the energy transition of inland navigation, it was essential to agree on a scope for the roadmap and on key definitions. In particular, it was decided to:

  • lay focus on inland navigation, meaning the transport of goods and the carriage of passengers by inland waterway vessels -recreational crafts, service vessels and floating equipment were not included at this stage, 
  • define emissions as atmospheric pollutants and greenhouse gases (GHG) arising from the operation of an inland navigation vessel’s propulsion and auxiliary systems,
  • adopt a “tank-to-wake” approach, as an interim solution, until a “well-to-wake” approach is available for the relevant energy carriers. Application of this approach however implies making assumptions, notably concerning the upstream chains (emissions produced and fuel availability), which are idealised.



In particular, the roadmap aims to outline, in addition to a business-as-usual scenario, two transition pathways for the fleet (new and existing vessels), meaning how the entire fleet will evolve by 2050.

A more conservative transition pathway, based on technologies that are already mature, is cost efficient in the short-term but with uncertainties on the availability on certain fuels, and a more innovative one, relying on technologies still in their infancy stage but providing more promising emission reduction potential in the long run.

The transition pathways also address the role which the different technological solutions will play in the energy transition challenge, assess their suitability according to the different fleet families in Europe and the sailing profiles of the vessels.

Technologies considered in the pathways

Table 1. Technologies considered in the pathways - energy carriers and converters (source: CCNR)

Remark 1: Regarding the energy converter, the mono-fuel engine is considered in the transition pathways for each fuel. In practice dual-fuel engines could also be applied, e.g. engines that run on LNG and gasoil but have significantly higher GHG emissions. This could also apply to MeOH and H2 engines once these enter the market.

Remark 2: The stage “CCNR 2” refers to the emission limits adopted by the Resolution CCNR 2005-II-20 (CCNR 2005). The EU Stage V refers to emission limits adopted by Regulation (EU) 2016/1628 for non-road mobile machinery (European Parliament 2016) (categories IWP, IWA, NRE or EURO VI marinised truck engines).

Transition pathways leading up to 2050

 Figure 1. Business-as-usual scenario: development of technologies by 2050 (source: CCNR)

In summary, the outcome of this business-as-usual scenario is that the air pollutant and GHG emissions targets to be achieved in 2050 as provided for in the Mannheim Declaration cannot be achieved. Specific measures must be taken to achieve these objectives

 Figure 2. Conservative transition pathway: development of technologies by 2050 (source: CCNR)

 Figure 3. Innovative transition pathway: development of technologies by 2050 (source: CCNR)

The two transition pathways are both sufficiently ambitious to achieve the emission reduction objectives of the Mannheim Declaration. A key conclusion points to the absence of a “one size fits all" technology solution adapted to all types of vessels and navigation profiles. A technologically neutral approach appears therefore relevant to achieve the energy transition.



Initial estimates show that the financial challenge involved in achieving the aim of zero emissions by 2050 is considerable. Depending on the fleet transition pathway, the financial gap to be bridged to achieve the Mannheim Declaration emission reduction objectives varies significantly but amounts to several billions in any scenario. The energy transition-related costs will exceed the financial resources of the navigation profession, which will only be able to bear a part of the costs required to achieve this transition. Significant grants are needed to close this gap, and to make the transition pathways economically viable for the inland navigation industry, energy suppliers, and shore-side infrastructure operators. Strong public support is therefore necessary.

In order to support the energy transition of the inland waterway transport sector, the CCNR considers it opportune to pursue the idea of a European-wide financial support instrument for the energy transition of the inland waterway transport sector, based on mixed sources (public and private), including a sector contribution. To ensure a level playing field, such an instrument should be open to EU countries as well as Rhine and Danube riparian states which are not members of the EU (Switzerland, Serbia, Moldova and Ukraine, in particular). Easy access to such an instrument is paramount, as is administrative simplicity.



Economic, technical, social and regulatory aspects need to be considered to tackle the challenge of the energy transition towards zero emissions. How to address them through concrete policy measures was a guiding question when developing the implementation plan proposed in the roadmap, which aims at suggesting, planning and implementing measures to be adopted directly or not by the CCNR, as well as monitoring the intermediate and final objectives laid down by the Mannheim Declaration.

Table 2. Implementation plan (source: CCNR)

The CCNR undertakes to

  • report by 2025 on the progress in the implementation as well as the need to update the roadmap,
  • at the latest in 2025 evaluate whether it is opportune to revise the CCNR’s study, especially on the economic and technical evaluation of the technologies,
  • review the “tank-to-wake” approach in a forthcoming revision of its roadmap,
  • evaluate by 2025 whether it is opportune to extend the scope of the roadmap, for example to other greenhouse gases such as N2O or to emissions associated with other aspects of the vessel’s life-cycle, to the manufacturing and disposal of propulsion systems, to other types of vessels, or even to the technologies’ safety,
  • revise, if necessary, by 2030 the roadmap and the corresponding action plan.

Eventually, the CCNR aspires to this roadmap being of assistance in developing a shared vision of the energy transition and the concomitant challenges within the inland navigation sector. In particular, this publication in the framework of the Smart Rivers conference aims to broaden the scope of discussion at global level and allows possible exchange of views on the energy transition of the inland navigation sector in different parts of the world. It is desirable to deepen this cooperation to learn from each other and ensure that the policy measures are properly tailored to the opportunities and challenges of the inland navigation sector.


To learn more about the roadmap and the CCNR’s contribution to emissions reduction:

To learn more about the CCNR: https://www.ccr-zkr.org/

Authors: Raphael Wisselmann, Laure Roux, Benjamin Boyer from the Secretariat of the Central Commission for the Navigation of the Rhine (CCNR)

For more information, you can contact Laure Roux at l.roux@ccr-zkr.org 





CCNR (2005): https://www.ccr-zkr.org/13020400-en.html

CCNR (2021): CCNR study on energy transition towards a zero-emission inland navigation sector. https://www.ccr-zkr.org/12080000-en.html

European Parliament (2016): Regulation (EU) 2016/1628 of the European Parliament and of the Council of 14 September 2016 on requirements relating to gaseous and particulate pollutant emission limits and type-approval for internal combustion engines for non-road mobile machinery, amending Regulations (EU) No 1024/2012 and (EU) No 167/2013, and amending and repealing Directive 97/68/EC (Text with EEA relevance). https://eur-lex.europa.eu/eli/reg/2016/1628/oj