Shipping and the Environment

How is maritime transport responding and contributing to an ever-increasing global pressure to reduce humanity’s carbon footprint?

A relentless global population increase is directly proportional to the continued growth in shipping over the past 100 years. Shipping can make a significant contribution to global carbon reduction targets and reaching the temperature goals of the Paris Agreement.

IMO published its Initial Strategy on reduction of GHG emissions from ships at MEPC 72 in 2018, setting a 2050 target of 50% reduction in carbon emissions compared to 2008 levels. This initial strategy includes both short-term measures, aiming at reaching peak emissions level as soon as possible, and long-term measures, aimed at reaching the 2050 reduction targets.

In Europe, the European Commission is preparing its Green Deal, aiming at a carbon-neutral Europe by 2050. This will probably include all forms of transportation, including domestic as well as international shipping in European waters.

The maritime transport industry has developed extremely sophisticated fuel handling and propulsion machinery over the last 50 years that are capable of utilising essentially what is left over from the refining process of crude oil. These fuels produce GHGs (CO2) as well as local pollutants (SOx, NOx and particulates).

Regulators have initially focused on local pollutants.

With an aim to reduce SOx emissions, a Global Sulphur Cap was introduced on 1st January 2020. This led to a shift from high sulphur (on average 2.8%) fuel oil to low sulphur (max. 0.5%) fuel oil as the most common fuel in the shipping industry. A small percentage of the world fleet installed Exhaust Gas Cleaning Systems (scrubbers) to enable these vessels to continue burning high sulphur fuel oil. Burning HFO and then scrubbing the exhaust gas and disposing of the waste to the sea or ashore is problematic and/or expensive. It is, however, a short-term solution that is likely to be regulated if not prohibited in the future.

Regulations on NOx emissions are also being gradually tightened. Since these emissions are mostly engine and not fuel related, tighter regulations apply to new vessels only. A stricter Tier III norm is gradually being implemented, starting in North America (2016) and parts of Europe (2021). Tier III compliance for oil-burning engines requires additional measures, such as Exhaust Gas Recirculation (EGR) or Selective Catalytic Reduction (SCR). Many dual fuel engines burning natural gas (methane) do not require these additional measures.

LNG scores much better than fuel oil on both SOx and NOx emissions. This has, however, not yet led to large scale investments in LNG-fuelled vessels. A recent DNV-GL report (2020) indicates that less than 1% of the world fleet is LNG-fuelled and the orderbook for new vessels consists of some 10% of LNG-fuelled vessels.

Following the introduction of the Global Sulphur Cap, the industry’s focus is on reducing GHG emissions. There is general agreement that short-term measures, both technical and operational, will contribute to reducing GHG emissions. They will, however, be insufficient to reach the 2050 reduction target. For this, new low or zero carbon / carbon-neutral fuels will be required.

A large number of studies have been undertaken and published in recent years. SGMF has, together with SEA-LNG, commissioned Thinkstep (now Sphera) to carry out a Lifecycle GHG Emission Study on the Use of LNG as Marine Fuel. The study was published in January 2020 and concludes that, on an engine technology basis, the absolute Well-to-Wake emissions reduction benefits for gas-fuelled engines today, compared with HFO-fuelled ships, are between 14% to 21% for 2-stroke slow speed engines, and between 7% to 15% for 4-stroke medium speed engines.

The study may be downloaded here.

Recently (as of September 2020), Sphera was commissioned to carry out an update of this study, which will include a thorough review of future alternative fuels.

SGMF is of the view that the shipping industry cannot shift from its reliance on present fossil fuels to new sustainable fuels within a short period and in a single step. Fossil LNG is currently the best available option, both in terms of local pollutants and GHG emissions. When more sustainable alternatives become available, fossil LNG can be replaced by Liquefied Bio Gas (LBG) and/or Liquefied Synthetic Methane (LSM) without further investments in the fuel supply chain and equipment onboard.

LBG and LSM will form part of the future fuel mix, together with e.g. LPG, hydrogen, ammonia, and methanol. SGMF is putting efforts into convincing regulators to make decisions based on a neutral and practical assessment of all alternatives being considered.

To this effect, SGMF has provided the IMO with information about methane slip development of dual fuel engines and suggestions on how to regulate methane emissions. Also, SGMF provided comments on IMO’s Fourth GHG Study, which was published in July 2020.

The Society is convinced that a switch to gas is a clear tangible step in the right direction. It is not a perfect solution to reduce emissions and catch-up with other sectors such as road transport and power generation.  Ships have to continue to carry fuel with them. There is no doubt maritime can do its part in helping to combat climate change by reducing fuel consumption and making the transition to sustainable fuels. It will require large investments in fuels and technology, for which funds have to be made available. The transition will require a practical goal-based approach.