In this episode (2/2), Michael Barnard concludes his conversation with Tristan Smith, a leading voice in maritime decarbonization and professor at the UCL Energy Institute, to unpack the tangled web of choices, regulations, and constraints facing the shipping industry as it attempts to cut emissions. From dual-fuel ships and synthetic fuels to compliance markets and long-term infrastructure investment, our conversation covered the broad terrain that policymakers, shippers, and fuel producers are all trying to navigate—with varying degrees of alignment and clarity.

The core challenge, as Tristan makes clear, is the uncertainty. Despite rhetoric about decarbonization, the shipping industry remains paralyzed by confusion over which fuel pathways will ultimately dominate. LNG got a big early lead, with over half of dual-fuel ships opting for it before the IMO's revised climate strategy took hold. But now? Stakeholders are stuck in a feedback loop: shipbuilders hesitate to commit without clarity on fuel availability, and fuel suppliers can’t scale up without clear demand signals. Hydrogen and synthetic fuels are still expensive and energy-intensive. Methanol offers potential but with its own limitations. Even advanced biofuels are subject to competing demands, especially from aviation. The result? Fleet choices made today could lock in constraints that ripple out for decades.

We dove into the IMO’s recent regulatory shift, a surprisingly muscular move for a UN body. The new rules focus not just on emissions, but on the carbon intensity of the fuels ships burn. GHG Fuel Intensity (GFI) targets are now baked in, with meaningful penalties: ships that fail to comply will pay fines starting at $100 per ton of CO₂, with funds used to accelerate zero- and near-zero-emission fuel development and assist lower-income countries with energy transitions. It's not a symbolic gesture. Modeling suggests the system could generate $11–12 billion annually in the first three years alone, creating a $33–36 billion fund for global maritime decarbonization. For once, there’s a stick and a pot of carrots.

Tristan stressed the importance of early action. Ships being built now will still be in service by 2050, and port infrastructure decisions last even longer. Regulatory clarity today means the excuses are drying up. Planning needs to happen now to avoid locking in fossil dependency for another generation. The regulation also means that even if the industry’s fuel mix is uncertain, the cost of carbon is not. That changes investment calculus across the board, from ship design to bunker fuel contracts.

We also touched on the equity angle. If global shipping decarbonization happens only in the wealthiest ports, it undermines the whole effort. The transition must include support for infrastructure, workforce training, and technology deployment in lower-income nations. Otherwise, we're just pushing emissions and economic pain offshore—literally.

This conversation reinforced what I’ve argued for years: while aviation drags its feet and road transport electrifies at speed, shipping sits in the middle—finally regulated, still confused, and facing real opportunity. The IMO’s climate strategy isn’t perfect, but it’s real, binding, and globally coordinated. It’s a serious signal to a sector long stuck in the waiting room of decarbonization. Now the countdown has started.