The reductions required under the Kyoto Protocol include domestic shipping emissions but exclude international emissions from shipping (and from aviation). The UNFCCC has given responsibility for emissions from international shipping to the International Maritime Organisation (IMO). The CCC analysed the potential for reducing emissions from shipping in its December 2008 report.

This recommended that both domestic and international shipping is included in action taken to reduce global emissions:

• Current global CO₂ emissions from shipping are roughly 1GtCO₂.

• Global shipping demand has risen rapidly, with freight tonne-miles growing at around 3.5% per year.

• Future projections of shipping emissions suggest that in a world without significant policy action we are likely to be on a path that would lead to global shipping emissions of 2.4 – 3.6 GtCO₂ in 2050. This would be around a two-threefold increase on today’s levels.  

How does shipping contribute to global CO₂ emissions?

Global shipping (domestic and international) already accounts for roughly 3% of global CO₂ emissions and could account for between 15-30% of all CO₂ emissions permitted in 2050 according to CCC analysis.






















How could technology reduce emissions from shipping?

There are a number of ways in which technological improvements can help to reduce emissions of harmful GHGs from ships:

• The design of hulls and propellers could be improved to reduce resistance and increase efficiency of travel through the water.  

• A shift to larger ships would allow to carry the same amount of load more efficiently, although would raise practical issues with port infrastructure.

• Alternative fuels could be used to power ships, such as liquefied natural gas, wind power, biofuels and solar energy.

A state-of-the-art 2010 ship could emit 27-32% fewer emissions compared to a typical 2010 in-service ship. However, ships usually last for around 25 years so stock changes slowly. Retro-fitting ships with new technologies may be necessary in order to achieve significant cuts in emissions.

What are the appropriate strategies and policies towards international shipping?

There is currently no policy framework to reduce international shipping emissions. In 2009 the International Maritime Organisation (IMO) made some progress with its advice on Energy Efficiency Design and Operational Indices (EEDI & EEOI) for new and existing ships. In addition, the IMO also remains open to cap and trade schemes that would provide strong incentives to achieve emissions reductions through their operational and design measures, and to purchase emissions reductions in global carbon markets.  In parallel, the EU has made a commitment to include international shipping in its climate and energy package and targets by 2013 if the IMO have not achieved an international agreement by end-2011.

What is the UK’s share of international shipping emissions?

There is significant uncertainty over the methodology of how emissions should be allocated to individual nations. Ships arriving in the UK may have called at numerous ports en-route, unloading and loading cargo along the way. As a result of this, there is uncertainty over how to allocate shipping emissions, as it is unclear within which nation’s waters emissions have been produced. Given this, the CCC advised that it is not clear how shipping emissions should be allocated to the UK level. The focus in international shipping should therefore be towards getting a global agreement to reduce emissions from this sector, which could bypass the need for allocation at the national level.

Why are international shipping emissions not included in the carbon budgets?

The budgets, in line with the Committee’s advice, exclude emissions from international shipping for the time being given the complexity of attributing shipping emissions to individual countries or regions, and a lack of an existing appropriate methodology for doing this. This allocation issue could be difficult to overcome; therefore the Committee has advised that a global cap would be a more appropriate way forward with an EU-only approach a second best solution.