Decarbonisation – is it sustainable?

Malcolm Latarche

Malcolm Latarche · 23 December 2019


Sustainability and Decarbonisation have become the modern mantra for shipping and for other users of energy as IPCC scientists say that climate change needs more effort. But some are asking if we are merely swapping one problem for another.

Hardly anybody, even most of those promoting alternatives to fossil fuels, seriously believe that oil, gas and coal are going to disappear anytime soon. In fact every analysis of the world demand for energy shows physical volumes of fossil fuel use still increasing albeit at a very slightly slower rate than renewables.

The big problem with fossil fuels is that despite some wild fluctuations in price they generally represent the cheapest means of producing power for consumers in all but a few very fortunately located nations. And people are addicted to power so much that few could imagine life without it. Smart phones, Apps, wi-fi connectivity and broadband control so many things that not long ago we would never have even dreamed about using them for. Things like calculating how many calories we have used up walking to work, asking Alexa what the weather will be or what is the name of that song that I can’t get out of my head.

Even in less developed parts of the world where power is not taken so much for granted we can see the beginnings of the modern consumer society taking root even if the lack of power production means that hospitals cannot work around the clock, light and heat are not available on tap and public transport hardly exists.

As far as shipping goes, we are looking to decarbonise the industry using a combination of alternative fuels and efficiency measures. Both of these can reduce the carbon emissions of ships but at the moment there is nothing to eliminate all carbon emissions. A lot of faith is being put into hydrogen and ammonia which will achieve that aim but at an unknown cost.

As things stand, production of both these potential fuels actually consumes more energy than they can release when used onboard a ship. Although some new methods of producing ammonia are being explored, the traditional methods used today account for over 1% of CO2 emissions more than any other industrial chemical-making process. Then there are the quantities – all of the world’s hydrogen production today would not be sufficient for half of shipping’s needs even if it was all diverted to shipping.

Ammonia has similar problems. Some 70 – 80% of all the ammonia produced today is for fertiliser use. Without it a large part of the world population would likely starve. Not all of the world’s fertiliser use is for food crops a significant part is used to help grow biofuels. A growing world population will add to pressure on agriculture which may need to shift from biofuels to food making decarbonisation even more difficult to achieve. What ammonia produced today that is not used for fertiliser is needed for other manufacturing processes.

Unless the new ammonia production methods are proved to work, we shall have to rely on current methods and that means that although ammonia used as a marine fuel would mean no CO2 emissions from the ship, there would not actually be any reduction in overall CO2 emissions.

The answer we are told is Green hydrogen and ammonia, that is when the materials are produced using renewable energy. The world today is reluctant to make use of nuclear power so the choice comes down to wind, solar and hydroelectricity. The later is sustainable is some places but not others and wind and solar also have problems.

The investment that would needed for expanding renewable power sources sufficient to produce new fuels to replace fossil fuels for shipping alone has never been quantified and is not likely to be so any time soon. Shipping’s share of fossil energy use is actually very small but it is doubtful if any organisation would be prepared to make an investment that catered for shipping alone. There a wholesale replacement of fossil fuels would be needed and that cost would be enormous.

The question is whether the world as a whole is prepared to make that investment or whether it might be preferable to spend the money on adaptation measures.

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