solutions to decarbonize maritime traffic

Every Saturday we decipher climate issues with François Gemenne, professor at HEC, president of the Scientific Council of the Foundation for Nature and Man and member of the IPCC.

We often talk about airplanes when we talk about sectors that contribute significantly to greenhouse gas emissions. By forgetting another sector, responsible for almost as many emissions: international maritime traffic.

François Gemenne: Greenhouse gas emissions from international maritime traffic represent almost 3% of global emissions, only slightly less than aviation. And it’s not just carbon dioxide: there’s also methane and nitrous oxide, not to mention fine particles, because most boat engines use heavy fuel oil, which is really the one of the dirtiest fuels in the world. And the bad news is that these emissions are increasing very quickly. Because more than 80% of goods consumed in the world are transported by ship.

“If we do not make drastic changes, at the current rate of growth, the International Maritime Organization predicts that emissions from international maritime transport could represent 17% of emissions in 2050.”

François Gemenne

at franceinfo

But alongside this structural trend, there is also a cyclical element which has caused emissions to explode in recent months: the drop in traffic in the Panama and Suez canals.

What is causing this drop in traffic?

These are two different problems: in Panama, which is a canal fed by fresh water, it is a drought problem. In Suez, it is the Houthi rebels who attack the boats. But in both cases, the consequence is the same: compared to their peak in recent months, traffic in the Suez Canal is down 42% last January, and that in the Panama Canal is down by 49%. However, these two canals are of vital importance for international trade: 6% of world traffic passes through the Panama Canal, and for Suez, it is double! And with the problems affecting these two channels, many carriers are choosing to reroute their boats, in particular by taking them through the Cape of Good Hope.

This makes journeys much longer, especially since boats are often forced to increase their speed to make up for lost time. And if you increase the speed by 1%, you increase your emissions by more than 2%. Unctad, the United Nations agency for trade and development, has done the calculation: a container ship traveling between Singapore and France, and which must be diverted by the Cape of Good Hope, increases its emissions by 70%. It is enormous !

The alternative fuels trail

To avoid this, first we must secure the passage through the Suez Canal, and the attacks by the Houthi rebels are obviously linked to the war in Gaza. For the Panama Canal, we are facing a structural problem, since droughts will increase, particularly due to climate change. It’s a vicious cycle. And above all, we must look for structural solutions: the first is to develop alternative fuels. We naturally think of LNG, liquefied natural gas, which equips more and more boats, but which also emits greenhouse gases. There are also biofuels, such as methanol, produced from carbon dioxide and hydrogen, or an ammonia derivative, produced from hydrogen and nitrogen.

The second solution is to change the boats themselves. By 2030, we expect 10,000 sailing cargo ships, i.e. around 10% of traffic.

“Sailing cargo ships are currently in full development, and it is clearly a future solution for decarbonizing the sector.”

François Gemenne

at franceinfo

And it is the French SMEs who are at the forefront: I cannot name them all here, but it is estimated that a third of the development of sailing cargo ships is taking place in France, particularly with the Atlantic shipyards.

And then, the third solution is obviously to relocate part of the economy, to reduce the distance traveled by goods, or at least to slow down the speed of boats: lowering the speed by 10%, that’s save more than a quarter of emissions. We’ll have to do all of this at once.

How can we deploy these solutions more quickly?

There are two acceleration factors: the first is that the three largest shipowners in the world are European: the Italian-Swiss MSC, the Danish Maersk, and CMA-CGM, which is French. This means that these are largely emissions that depend on us, for which we can legislate, encourage innovation, etc.

And the second is a figure that will come as a surprise. It is estimated that 40% of international maritime traffic is used to transport fossil fuels: wood pellets, coal, oil, and increasingly gas. We burn 40% of what we transport. This may seem hopeless, but in fact it is good news: if we manage to quickly move away from fossil fuels, it also means that we will reduce maritime traffic by 40%. We kill two birds with one stone.