An integrated perspective on the decarbonization of shipping

As climate change escalates, the imperative to decarbonize all human activities intensifies¹. In the shipping industry, the transition from oil products to biofuels and e-fuels (or electrofuels) is essential for deep emissions cutbacks. This transition requires developing the production capacity of low-carbon fuels and alternative vessel motorization. By contrast, techno-economic challenges arise from the high diversity of candidate low-carbon fuels, their specific drawbacks compared with oil² and the relatively young age of the current shipping fleet³, which could lead to substantial lock-in effects. The International Maritime Organization (IMO) has reached agreements to reduce or eliminate shipping emissions by 2050, yet its ambitions arguably lack a comprehensive global energy system perspective. Although some studies have delved into scenario analyses for shipping emissions, they often overlook the broader context of climate action. Notably, economy-wide integrated assessment models (IAMs) — the backbone of IPCC mitigation reports — have historically sidelined the modelling of shipping.