09.11.20 Avast those emissions! Dariush Jones • 8 min.

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The sea has long been synonymous with freedom. For the maritime transport industry, this has meant the freedom to burn heavy oil and emit lots of carbon. But recent studies show that maritime carbon emissions are significant and will increase – unless technological advances and regulation put freighters and tankers on a new, more sustainable course.

The energy transition is largely land-locked. Perhaps because cars, trucks, and jet aircraft are common sights, but ships and barges much less so. And when they do heave into view – in Rotterdam or Hamburg, along the Seine or the Rhine – they tend to be viewed as an attraction rather than a means of transport.

That’s not the shipping lines’ fault. But being under the radar may work to their advantage. After all, about 90% of the EU’s foreign trade travels by water; for intra-EU trade, the figure is 40%. Add to that fishing, tourism, and pleasure-crafting. For example, 2,000 vessels ply the Baltic Sea at any given moment.

The rising tide of maritime carbon

Maritime transport is responsible for about 2.6% of global carbon emissions, similar to the aviation industry’s 2.7%. Ships also pollute oceans and rivers with toxic waste water, chemicals (peeling paint, for example), soot, and noise. But whereas aviation faces growing pressure to emit less, maritime transport’s carbon footprint has widened by 10% in the last six years. And a recent study forecasts that it could increase by 50% by 2050, a year by which many countries want to be climate-neutral.

True, ship engines have become more efficient, and new laws place limits on the sulfur content of their exhaust. But on the high seas such laws can be difficult to enforce. Regulations differ by country and degree of severity. Besides, profits in the industry are high, so fines are an ineffective deterrent or simply considered the price of doing business.

Moreover, the industry isn’t addressed by the climate summits that set global targets for climate protection. Like aviation, maritime transport is considered too international for its emissions to be assigned to individual countries. Consequently, the responsibility for nautical decarbonization has been outsourced to the International Maritime Organization’s (IMO) Marine Environment Protection Committee.

The committee’s targets have so far been less than ambitious. For example, although the industry aims to reduce its carbon intensity by 40% by 2030, its total emissions will continue to rise. Also, there are no (effective) enforcement mechanisms and a lot of loopholes. John Maggs, President of Clean Shipping Coalition, an NGO, said that “in pursuing this outcome at the IMO, many countries have knowingly broken their Paris Agreement commitment to pursue a 1.5/2C compatible emissions reduction.”

Cleaner propulsion systems

Since effective regulatory policies and economic incentives don’t seem to be in the offing, perhaps technological developments—like new propulsions systems that could render heavy fuel oil obsolete – offer greater hope. Liquid natural gas (LNG), for example, has several big advantages over heavy oil, although LNG ships remain rare. “LNG bears the potential to … lower the climate impact of shipping.... Sulphur oxides, particulate matter and heavy metal emissions can be avoided almost entirely.,” writes the Nature and Biodiversity Conservation Union (NABU), a German NGO. “Nitrogen oxides and ultrafine particles can be significantly reduced compared to the use of heavy fuel oil or marine diesel.” From a long-term perspective, however, LNG is a transitional fuel until ships run entirely on renewable sources.

One such source could be renewable electricity, believes Asahi Tanker, a subsidiary of Japanese shipping giant MOL. In October 2020 it ordered the world’s first two zero-emission, electric-powered tankers. Delivery is scheduled for March 2022 and March 2023, respectively. Their engines will be much quieter than conventional ship engines and therefore less of a disturbance to marine life. The problem is that they require enormous batteries, which makes electric propulsion an unlikely option for most of shipping lines.

Instead, the marine fuel of the future may be hydrogen. French rocket maker ArianeGroup and energy company ENGIE are working together to supply liquid green hydrogen to ships as early as 2030. Before then, however, ENGIE’s interim CEO Claire Waysand says two problems need to be solved: "The price of green hydrogen and the cost of liquefaction need to be lower… This will require a technological leap, but is feasible.”

ENGIE and Ariane will obviously face competition. The National Hydrogen Strategy that Germany adopted in June 2020, for example, intends for the country to significantly scale up its production of green hydrogen as a storage medium for electricity and as a fuel for buses, trucks, aircraft, and ships.

Rules of the sea

Getting ocean and river shipping on board the energy transition will require regulatory policies at the EU level. Transport & Environment, a Brussels-Based advocate for clean transport, recommends integrating shipping into the European emissions trading scheme. It also called on the EU to ignore the IMO’s modest climate targets and to set its own targets for maritime transport in the European Green Deal.

In short, maritime transport can only be decarbonized by taking an international approach. Ideally at flank speed. Because even if ships are largely invisible in the most people’s daily lives, their impact on the earth’s climate is unmistakable.


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