Navigating sustainability transitions: Implications of Green Growth and Post-growth pathways for the maritime transport industry

The ships that crisscross the oceans are the silent arteries of the modern world, carrying the raw materials, finished goods, and energy that keep global economies alive. For decades, the logic governing this industry has been simple and relentless: more growth is better. The prevailing belief has been that as economies expand, they produce more goods, consume more energy, and ship more cargo, creating a virtuous cycle of prosperity. This model assumes that technology can solve the environmental problems caused by this expansion, allowing us to keep growing while cleaning up our act. However, a different school of thought is gaining traction, suggesting that true sustainability might require us to slow down. This perspective argues that on a planet with finite resources, endless growth is impossible, and that we must instead focus on using less, repairing more, and living well within ecological limits. The maritime industry, with its massive ships and deep-rooted dependence on moving vast quantities of material, stands at the center of this debate. If the world shifts toward a future defined by green technology and continued expansion, or one defined by reduced consumption and local production, the fate of the shipping industry could change in ways that are difficult to predict.

A team of researchers at the Institute of Shipping Economics and Logistics in Germany set out to explore these two very different futures. They did not try to predict exactly what will happen, but rather constructed detailed scenarios to see how the industry might adapt. They compared a standard path of continued economic growth against two alternative sustainability pathways: "Green Growth," where the economy keeps expanding but becomes cleaner through technology, and "Post-growth," where the economy deliberately reduces its material and energy use to stay within planetary boundaries. By examining how these different paths would alter what people buy, how they produce it, and how far it needs to travel, the researchers mapped out the likely consequences for cargo ships, ports, and the industrial hubs that surround them. Their work reveals that the industry is not just facing a change in fuel types, but a fundamental restructuring of its entire purpose.

The study found that under a Green Growth scenario, the world continues to trade and consume, but the nature of what is being shipped changes dramatically. The massive volumes of oil and coal that currently dominate global shipping would decline as the world shifts to renewable energy. In their place, new cargo streams would emerge, carrying hydrogen, ammonia, and the critical minerals needed for batteries and solar panels. Ports would transform from simple loading docks into complex energy hubs, processing and storing these new fuels. While the total amount of goods moving might still rise, the industry would face higher costs and the need for entirely new infrastructure to handle these cleaner, but often more complex, energy carriers. The researchers suggest that in this future, success would depend less on moving the most cargo and more on providing specialized services that support a decarbonized global economy.

The picture becomes even more distinct under the Post-growth pathway. Here, the assumption is that the world actively chooses to use fewer resources. This means a deliberate reduction in the demand for long-distance shipping. If people buy fewer new products and instead repair or reuse what they have, the need to transport manufactured goods across oceans diminishes. The researchers found that this would lead to a significant drop in the volume of container ships and liquid bulk tankers. The era of ultra-large ships designed to move millions of tons of cheap goods might give way to a system where shorter, regional supply chains are the norm. In this scenario, ports would face a stark reality: the traditional model of expanding capacity to handle ever-increasing volumes would no longer work. Instead, these facilities would need to reinvent themselves as centers for circular economy activities, such as recycling, remanufacturing, and regional production. The focus would shift from maximizing the speed and volume of throughput to creating value through efficiency and local integration.

A key finding of the research is that both pathways, despite their differences, point toward the same conclusion: the old business model of relying on endless growth in cargo volumes is becoming risky. The industry has built its infrastructure, from the largest container ships to the deepest port terminals, on the expectation that trade will always increase. The researchers argue that this creates a vulnerability. If the world moves toward a Post-growth future, or even a Green Growth one that moves slower than expected, these massive investments could become "stranded assets"—infrastructure that is too large or too specialized to be useful in a world of lower demand. The study suggests that the greatest danger for the industry is not choosing the wrong future, but failing to prepare for multiple possibilities.

The researchers emphasize that this is not a story of inevitable decline, but of necessary transformation. Even in a future where less is moved, there are new opportunities. Ports could become the heart of regional industrial ecosystems, where waste from one process becomes the fuel for another. Shipping companies might find new roles in managing the complex logistics of a circular economy, moving materials for recycling rather than raw resources for new production. The study concludes that the industry's future competitiveness will depend on its ability to adapt. Rather than betting everything on a single vision of endless growth, maritime leaders and policymakers need to embrace "scenario thinking." This means planning for a range of plausible futures, diversifying their investments, and building flexibility into their systems. The ships of the future may not be bigger or faster, but they will need to be far more versatile, capable of navigating a world where the definition of progress has fundamentally changed.