How to Balance Trade-Offs When Decarbonising the Shipping Industry


Christiaan De Beukelaer, a researcher at the University of Melbourne, on the tricky tightrope the industry must cross in its green pursuit. Christiaan’s book, Trade Winds: A Voyage to a Sustainable Future for Shipping, comes out in January.

Fossil fuels

The need to decarbonise the shipping industry is now abundantly clear. The path towards zero emissions less so. No silver bullet technology or fuel currently exists that can substitute for fossil fuels.The pathway to decarbonise the industry, which currently burns some 300 million tonnes of fossil fuels a year, thus lies in finding a balance between different approaches.

The need to decide on the trade-offs this requires was, at face value, the key message of the inaugural Summer Institute on Maritime Decarbonisation at the World Maritime University in Malmö, which took place last month.

The question of trade-offs is what I wish to explore here, by adding some elements into the equation that never quite made it to the syllabus at the World Maritime University. Their summer institute focused primarily on lowering the energy intensity of ships and on the carbon intensity of fuels.

Simply put, WMU academics focused mostly on the technical measures that can help shipping become more efficient, with some mention of operational measures and the regulatory environment. This focus is crucial, albeit insufficient.

Designing new ships

In terms of ship design, reducing resistance and improving propulsion efficiency can help lower the energy intensity of ship operations. Though the gains of most of these interventions are relatively small, they can help slow emissions growth (relative decoupling).

Indeed, despite commitments to the contrary, shipping emissions decreased by 1% during the first year of the pandemic (mostly thanks to an 8.8% drop during the first half of the year – and rebounded by 4.9% in 2021.

The most promising technological improvement to ships is to harness the wind aboard ships for direct (assistance with) propulsion. Retrofitting existing (and designing new) ships to embrace the millennia-old technology that never required burning fossil fuels should a top priority.

Today, there is a variety of wind propulsion and assist technologies that have proven their economic and environmental worth and can be – and are – deployed easily.

Even when the potential of wind propulsion and marginal gains from reducing hull resistance and propulsion efficiency is fully exhausted, some mechanical propulsion will be needed for almost all ships. This means that zero-emissions fuels are needed.

The perfect fuel “zero emission” doesn’t quite exist, as the alternatives to fossil fuels come with trade-offs of their own. First, the amount of renewable electricity needed to generate enough power to propel all ships equals that of all the renewable energy currently generated in the world.

Secondly, it is not enough to change what happen aboard ships: The necessary shore-based infrastructure for the production, storage, and delivery of alternative fuels amounts to nearly nine-tenths of the more than one trillion dollars needed to meet IMO’s existing targets.

Third, a detailed analysis of the environmental cost (beyond carbon emissions) of any alternative fuel (and its production process and the materials needed for this) is needed to ensure the energy transition solves, rather than shifts, the problem.

Fourth, any leakage of alternative fuels would cause great environmental harm; ammonia is highly toxic and would burn the lungs of humans and other animals, while hydrogen is a far more potent greenhouse gas than carbon dioxide, making the environmental risk of slippage potentially disastrous.

(I’m not even going into the risk of methane slippage from LNG, as this fossil fuel has no place in the energy transition – despite the current order book suggesting that many shipping executives think otherwise.)

In short, there really isn’t a silver bullet that will allow us to tackle the climate crisis by simply swapping one fuel for another. This is roughly as far as WMU’s Summer Institute on Maritime Decarbonisation went. To their credit, they covered an awful lot in a succinct manner. Though I was left with a big open question: Can more ambitious regulation speed up the transition?

The challenge the industry faces is far larger than the initial IMO target from 2018 might suggest. A 50% reduction in emissions by 2050 on a 2008 baseline brings them back to 1990 levels.

That won’t do; they need to be reduced to zero well before 2050. The shipping industry’s remaining share of the global carbon budget to have a 66% chance of keeping warming below 1.5˚C was roughly 4.2-6.8 Gt in 2020.

At current emissions levels of roughly one billion tonnes of CO2 a year, that leaves us with less than five years of business as usual.

So, what options do we have to deal with this enormous challenge?

The first thing is to push for far higher levels of ambition at the IMO. Targeting a 90% cut in emissions by 2040 would be a great start. Setting the bar any lower may mean that shipping companies do not feel sufficient pressure to invest now and use every possible technological and operational tool currently available.

The second thing is to embrace all the options currently available to curb fuel use immediately, by as much as possible. While this will obviously reduce total emissions from the industry, it will also stretch the very limited remaining carbon budget to give us a fighting chance at keeping warming below 1.5˚C.

Even if that target is becoming more elusive by the day, every action that brings emissions down helps. And so does every tenth of a degree of warming we can avoid. This requires embracing slow steaming and wind propulsion – combined with any possible further gains to efficiency.

The less fossil fuel we need today, the less alternative fuel we’ll need in the future. More efficient ships will remain more efficient whether they run on HFO, VLSFO, Green Hydrogen, or Green Ammonia. The greenest fuel is the fuel we don’t use.

Efficiency wasn’t the elephant in the room during the Summer Institute. Indeed, wind propulsion, slow steaming, and the challenges inherent to “green” fuels were discussed at length. The significant thing that wasn’t? Money. The transition will cost money.

A lot of it. But that won’t just increase costs for shipping companies, ship operators, cargo owners, and crews. It will also affect the end users of the cargos transported.

That is where the crux of the challenge lies: How can we ensure that balancing the trade-offs between technological innovation, operational measures, and rethinking supply chains doesn’t mean that people in “developing” countries face higher prices for cargo transport.

If we can’t ensure a “just and equitable transition” that guarantees they won’t pay even more than they already do now, they might be hard-pressed to agree on greater ambition at the IMO.

Without the support of these developing countries (which commonly pay more than rich countries for shipping, as UNCTAD continues to document), the revision of its “initial strategy” risks becoming too weak to push for a rapid transition. If that happens, we’ll all lose.

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Source: Splash247


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