Most coverage of shipping decarbonisation is about fuels and vessels. Ammonia, methanol, green hydrogen, dual fuel engines. That is the visible half of the story, and it is the half that will not work without the other.
A ship that runs on clean ammonia needs somewhere to take it on. A cruise ship that shuts down its generators at berth needs a shore connection rated to carry the load. Both of those are civil and marine construction problems, delivered on working waterfront, usually while the berth stays operational. That is the part Australian ports are quietly working through now.
Where the regulation actually stands
It is worth being precise here, because the timeline is frequently reported as settled and it is not.
The IMO Net-Zero Framework is a set of amendments to Annex VI of the MARPOL convention, and it has two linked parts. A global fuel standard requiring ships to progressively reduce the greenhouse gas intensity of their fuel, and a pricing mechanism that puts a price on the emissions ships produce. It applies to oceangoing ships over 5,000 gross tonnage, which the IMO notes account for more than 85 per cent of global shipping emissions.
The framework was approved at the MEPC 83 session in April 2025. Adoption was then scheduled for an extraordinary session in October 2025, and that is where it stalled. The committee met from 14 to 17 October 2025 and agreed to adjourn the session for one year, with member states continuing to work towards consensus in the interim.
So at the time of writing the framework is approved but not adopted. Once it is adopted, the IMO expects entry into force roughly sixteen months later under the tacit acceptance procedure.
Why the delay changes less than it appears to
For a port owner, the uncertainty is about timing rather than direction. Shore power cables, bunkering berths and strengthened wharves have design lives measured in decades and lead times measured in years. A twelve month shift in a regulatory vote does not change whether the infrastructure is needed, and the sequencing argument for starting early is unaffected.
Australia already regulates ship emissions
The net-zero framework is the next step rather than the first one, which is easy to forget.
The sulphur cap is already in force and already changed the fuel supply chain. The IMO adopted the relevant MARPOL Annex VI amendments in 2008, and from 1 January 2020 the sulphur content of fuel oil used by ships has been limited to 0.50 per cent by mass or less.
Domestically that is given effect through Australian law. Marine Order 97 covers marine pollution prevention for air pollution, administered by the Australian Maritime Safety Authority, and AMSA sets out how MARPOL is implemented in Australia more broadly.
The pattern is instructive. Each tightening of the rules has shifted cost and complexity from the vessel onto the shore side, because compliant fuel has to be stored, blended, tested and delivered somewhere.
What low-emission shipping asks of a port
Translated out of policy language into physical work, the requirements fall into a handful of categories.
| Requirement | What it means on the ground |
|---|---|
| Shore power | High voltage supply, shore cable ducting, cable management, substations |
| Alternative fuel bunkering | New berths or modified berths, safety zones, transfer infrastructure |
| Heavier vessel loads | Berth and fender upgrades, piling, mooring capacity assessment |
| Deeper draught | Dredging, revetment and scour protection, quay wall checks |
| Electrified landside plant | Grid capacity, charging infrastructure, cable routes |
| Ageing assets | Remediation and strengthening of structures built for other duties |
Almost none of that is new technology. It is piling, sheet piling, concrete remediation, fabrication, fendering and marine services, carried out over water and around operating vessels. Our overview of what marine construction involves covers the disciplines, and the different types of marine construction sets out where each applies.
Shore power is already being built here
The most concrete example in the country is in Sydney, and it is further along than most people realise.
The claimed benefit is specific rather than vague. The Port Authority estimates a reduction of up to 4,000 tonnes of carbon dioxide a year, which it equates to taking around 1,100 cars off Sydney's roads, along with a reduction in ship noise of up to 10 decibels. Carnival, Royal Caribbean and MSC have committed to future use of the facility.
Two things are worth drawing out of that. The first is that it required a commitment from both the port and the shipping lines, because a shore connection nobody can plug into is a stranded asset. The second is that the hard part was construction in a live terminal on a constrained harbour site, which is a marine contracting problem rather than an energy one.
Western Australia carries the heaviest version of this
Australia's export tonnage is dominated by bulk commodities leaving the west coast, which makes WA the state where the fuel question lands hardest.
Work on that has been underway for some years. A May 2023 study by the Energy Transitions Commission for a consortium including the Global Maritime Forum, BHP, Rio Tinto, Oldendorff Carriers and Star Bulk Carriers found that clean ammonia powered ships on the iron ore routes between Western Australia and East Asia could be operational as early as 2028, reaching five per cent adoption by 2030, and identified the Pilbara as a viable bunkering option.
The same study put the scenario at more than 20 vessels running on clean ammonia by 2030, rising to roughly 360 by 2050, and was explicit that the corridor depends on bunkering infrastructure being available and on the safety case for ammonia as a marine fuel being validated and accepted.
Ammonia bunkering is not a fuel line on an existing wharf. It implies dedicated or heavily modified berths, exclusion and safety zones, spill and vapour management, and structures designed around a toxic cargo. That is a significant marine construction programme, and the timeline above means design and approvals work has to happen well before 2028.
Government has been mapping the same ground. The Commonwealth published an issues paper on green shipping corridors and partnerships as part of its maritime emissions reduction work, and its ports policy material sets out how port planning sits within national freight priorities.
The unglamorous work that actually enables it
Strip away the fuel branding and a decarbonising port is mostly an asset renewal problem with a deadline attached.
Structural capacity. Berths designed decades ago for different vessels and loads.
Piling and sheet piling. New dolphins, strengthened quay lines, reclamation and retention.
Concrete remediation. Spalling and reinforcement corrosion on structures that must now carry more.
Fendering and mooring. Energy absorption matched to the vessels actually calling.
Services through the deck. Cable and pipe routes retrofitted into existing wharf structures.
Staging and access. Barges, workboats and marine plant to work without closing the berth.
That last point drives programme and cost more than anything else. A port cannot stop handling cargo while its berths are upgraded, so the work is sequenced around shipping windows and delivered from the water. Our notes on why marine piling contractors matter on coastal projects and our vessels and equipment cover how that is resourced.
Material selection is becoming part of the brief too, since a port spending money to cut operational emissions is increasingly asked about the embodied emissions of the structure itself. Our piece on eco-friendly materials for modern jetty construction looks at where the genuine options are.
What port and facility owners can usefully do now
The regulatory date is uncertain. The engineering lead time is not, and that asymmetry suggests a clear order of work.
Start with condition and capacity. Knowing what your existing structures can actually carry, and what remediation they need regardless of decarbonisation, is the input every later decision depends on. A great deal of the work ports will do this decade is renewal they already owed.
Then establish what the vessels calling at your berths are likely to require, and when. Shore power only pays if ships can connect. Bunkering only pays if there is demand on that route. Both are commercial questions before they are construction ones.
Then get the enabling works into the program early. Grid connection, approvals, environmental assessment and marine access are the long poles, not the structures themselves. Our design and consulting and marine maintenance services exist for exactly this stage, and our project history includes port and harbour works such as sheet piling at Victoria Quay and sheet piling and land reclamation at Fremantle Fishing Boat Harbour.
If you are scoping works and want a realistic view of constructability, sequencing and marine access, get in touch.
Key points
Shipping decarbonisation depends on shore side infrastructure, not only on vessels.
The IMO Net-Zero Framework amends MARPOL Annex VI.
It combines a global fuel standard with a greenhouse gas pricing mechanism.
It applies to oceangoing ships over 5,000 gross tonnage.
Those ships account for more than 85 per cent of global shipping emissions.
The framework was approved at MEPC 83 in April 2025.
The adoption session met from 14 to 17 October 2025 and adjourned for one year.
At the time of writing it is approved but not adopted.
Entry into force is expected roughly sixteen months after adoption.
The 0.50 per cent sulphur limit has applied since 1 January 2020.
Marine Order 97 gives effect to air pollution rules in Australia.
Shore power at White Bay Cruise Terminal is described as an Australian first.
Construction there is expected to complete by the end of 2026.
It is estimated to cut up to 4,000 tonnes of carbon dioxide a year.
A WA to East Asia ammonia corridor identified the Pilbara as a viable bunkering option.
The honest summary is that Australian ports are preparing unevenly, and the constraint is rarely the technology. It is lead time, grid capacity, approvals and the practical difficulty of rebuilding a working berth without closing it. Those are solvable problems, and the ports that start on condition assessment and enabling works now will be the ones with options when the regulatory date finally lands.