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Audit-Ready Carbon Reporting for Marine Freight Shipping

Track bunker fuel by voyage, calculate ton-kilometer intensity, monitor vessel efficiency, and report IMO compliance and alternative fuel adoption.

The Industry Hotspot: Bunker Fuel Consumption and Vessel Efficiency

Most efficient freight mode per ton-km

Marine shipping emissions concentrate in bunker fuel combustion for vessel propulsion. Heavy fuel oil and marine gas oil power engines moving cargo across oceans and waterways. Vessel size affects efficiency with larger ships achieving better ton-kilometer intensity. Speed optimization balances fuel consumption versus transit time. Slow steaming reduces fuel burn but extends voyage duration. Deadweight capacity utilization determines efficiency—full vessels spread fuel across more cargo tons. IMO 2020 sulfur regulations drove fuel switching to low-sulfur fuels or scrubber installations. Energy Efficiency Design Index and Carbon Intensity Indicator measure vessel performance. Alternative fuels including LNG, methanol, and ammonia pilot in new vessel programs. NetNada tracks fuel consumption by voyage and vessel, calculates ton-kilometer intensity, monitors vessel efficiency ratings, and reports IMO compliance.

SASB Industry Definition

The Marine Transportation industry operates cargo vessels including container ships, dry bulk carriers, tankers, and specialized vessels for ocean and inland waterway freight. Operations center on bunker fuel combustion for propulsion with emissions depending on vessel size, cargo capacity, speed, and route distance. Carbon intensity measured in grams CO2 per ton-kilometer represents most efficient freight transport mode. IMO regulations drive emission reductions through efficiency standards and alternative fuels.

View SASB Standard →

Industry-Specific Carbon Accounting

No generic solutions. Metrics, data sources, and reporting aligned to Marine Transportation operations.

Voyage Fuel Consumption Tracking

Vessel fuel consumption varies by cargo load, speed, route distance, and weather conditions. Laden voyages with full cargo consume more than ballast returns. Container ships, bulk carriers, and tankers have different consumption profiles. Track bunker fuel consumption by voyage and vessel. Calculate fuel per ton-kilometer by vessel type and route. Report fleet fuel efficiency trends and benchmark by vessel class.

Fuel per ton-kilometer by vessel

Cargo Capacity Utilization Impact

Deadweight capacity utilization measures cargo carried versus vessel capacity. Fuller vessels achieve better ton-kilometer efficiency spreading fuel across more cargo. Empty or partial loads reduce efficiency. Monitor cargo weight and capacity utilization by voyage. Track ballast versus laden voyage mix. Calculate effective ton-kilometers accounting for utilization rates.

Capacity utilization tracked

Vessel Speed Optimization

Fuel consumption increases exponentially with speed. Slow steaming reduces fuel burn substantially but extends transit time affecting service offerings and competitiveness. Optimal speed balances fuel costs versus schedule. Track voyage speed and fuel consumption relationship. Monitor speed management programs. Calculate fuel savings from speed optimization versus baseline operations.

Speed optimization tracked

IMO Carbon Intensity Indicator Compliance

Carbon Intensity Indicator measures emissions per transport work annually. Vessels must achieve required reduction percentages versus baseline. Compliance through efficiency improvements, alternative fuels, or operational measures. Calculate CII rating by vessel annually. Track compliance status and required reductions. Report improvement measures implemented for CII compliance.

CII ratings tracked

Alternative Fuel Vessel Operations

LNG reduces emissions versus heavy fuel oil with lower carbon and sulfur. Methanol and ammonia offer pathways to very low or zero carbon fuels. Dual-fuel engines enable alternative fuel adoption. Track alternative fuel consumption by vessel and fuel type. Calculate emission reductions versus conventional fuel baseline. Report fleet alternative fuel capability and expansion plans.

Alternative fuel adoption tracked

SASB TR-MT Metrics Automation

Auto-generate disclosure including gross Scope 1 emissions, bunker fuel consumption by type, fleet average Carbon Intensity Indicator, deadweight capacity utilization, alternative fuel percentage, and customer emissions methodology. Footnotes cite fleet composition and trade routes.

SASB TR-MT compliant

Product Features for Marine Transportation

Use Carbon Data Uploader to import vessel fuel logs, cargo manifests, voyage reports, and CII calculations for marine shipping emissions tracking. Learn more →

The Activity Calculator applies factors for heavy fuel oil, marine gas oil, LNG, and alternative fuels—calculating vessel emissions and freight ton-kilometer carbon intensity. Learn more →

Marine Transportation Case Studies

How entities in this industry use NetNada to solve carbon accounting challenges.

Container Shipping Line (Global trade routes, Mixed owned and chartered fleet, Cargo owner customers requiring emissions data)

Challenge

Cargo owner customers required freight emissions for their Scope 3 logistics reporting. Bunker fuel consumption needed tracking by voyage and vessel for ton-kilometer intensity. IMO Carbon Intensity Indicator compliance required annual vessel ratings. Alternative fuel adoption strategy needed carbon quantification. Fleet efficiency optimization required voyage-level fuel analysis.

Solution

Implemented comprehensive marine shipping carbon accounting tracking bunker fuel by voyage and vessel. Calculated ton-kilometer intensity by route and cargo type. Monitored cargo capacity utilization affecting efficiency. Calculated annual CII ratings by vessel demonstrating IMO compliance. Generated cargo owner freight emissions using weight, distance, and vessel allocation.

Result

Established ton-kilometer carbon intensity baseline showing vessel type and utilization impacts. Achieved IMO CII compliance across fleet through speed optimization and efficiency measures. Provided cargo owners with freight-specific emissions supporting their Scope 3 reporting requirements. Identified efficiency improvement opportunities through voyage analysis revealing utilization and route optimization potential.

SASB Disclosure Topics for Marine Transportation

Material sustainability topics beyond emissions that investors and stakeholders expect disclosed per SASB standards.

Greenhouse Gas Emissions

environment

Track Scope 1 from bunker fuel combustion for owned and operated vessels. Report Scope 2 from port electricity and shore facilities. Calculate Scope 3 from time-chartered vessels, port services, and cargo owner emissions. Report emissions per ton-kilometer and per deadweight ton.

Fuel Consumption and Efficiency

environment

Monitor bunker fuel consumption by vessel and voyage. Track fuel per ton-kilometer and deadweight ton. Report fleet energy efficiency and Carbon Intensity Indicator compliance.

IMO Regulatory Compliance

governance

Track Energy Efficiency Existing Ship Index and Carbon Intensity Indicator by vessel. Monitor compliance with IMO sulfur regulations. Report IMO GHG strategy alignment and reduction pathway.

Alternative Fuels and Vessel Technology

business model

Monitor LNG, methanol, or ammonia-powered vessel operations. Track alternative fuel consumption and emission reductions. Report new vessel orders by fuel type and propulsion technology.

Cargo Utilization and Route Optimization

business model

Track deadweight capacity utilization by voyage. Monitor ballast versus laden voyage efficiency. Report route optimization and speed management programs.

Customer Freight Carbon Reporting

business model

Provide cargo owner emissions data for Scope 3 logistics reporting. Calculate emissions by shipment using weight, distance, and vessel type. Disclose allocation methodology and emission factors.

NetNada tracks all SASB material topics, not just emissions. Our platform supports disclosure across environmental, social, governance, and business model topics relevant to your industry.

Marine Transportation FAQs

Common questions about carbon accounting for this industry

Why is marine shipping the most efficient freight mode per ton-kilometer?
Large vessels carry enormous cargo weights across long distances. Container ships move thousands of containers per voyage. Bulk carriers transport tens of thousands of tons of coal, grain, or ore. Water transport has low friction compared to road or rail. Result: Fuel consumed per ton moved per kilometer is lower than any other freight mode despite slower speeds. Typical marine shipping emissions one-tenth of air freight and half of trucking per ton-kilometer.
How does vessel speed affect marine shipping emissions?
Fuel consumption increases exponentially with speed due to water resistance. Doubling speed can quadruple fuel consumption per distance. Slow steaming at reduced speeds dramatically lowers fuel burn and emissions but extends voyage time. Fleet operators balance fuel costs, schedule reliability, and service competitiveness. Report vessel speed management programs and fuel efficiency improvements from speed optimization.

Track Marine Vessel Fuel, Ton-Kilometer Intensity, and IMO Compliance

See how shipping lines monitor bunker fuel efficiency, calculate cargo carbon intensity, and generate SASB and IMO-aligned disclosures—automated from voyage and operations data.