• Shipping contributes around 3% of global GHG emissions, mainly from CO₂ generated by burning marine fuels.
• To address this, the International Maritime Organization (IMO) has introduced a series of regulatory frameworks aimed at reducing emissions.
• Consequently, GHG ratings have become a standard industry benchmark for shipowners, charterers, and regulators.

1. Energy Efficiency Design Index (EEDI)
   • Applicable to new ships built from 2013 onwards.
   • Indicates grams of CO₂ emitted per tonne-mile under design conditions.
   • Ensures progressive improvement in energy efficiency of newbuild vessels.
2. Energy Efficiency Existing Ship Index (EEXI)
   • Introduced in 2023 for existing ships.
   • Based on the same principle as EEDI but applied retrospectively to in-service vessels.
   • Compliance may require Engine Power Limitation (EPL) or retrofitting with energy-saving devices.
3. Carbon Intensity Indicator (CII)
   • Operational rating system, in force from 2023 onwards.
   • Calculates grams of CO₂ per dwt-mile based on annual fuel consumption and distance travelled.
   • Ships are rated from A to E (A = best, E = worst).
   • A ship rated D for 3 consecutive years or E in any single year must submit a corrective action plan.
4. Commercial GHG Ratings (e.g., RightShip)
   • Independent platforms such as RightShip assess ships based on design efficiency relative to peers.
   • These ratings directly influence charterer preference, hire rates, and commercial competitiveness.

The Second Engineer, being responsible for day-to-day machinery operations, plays a key role in reducing fuel consumption and improving GHG ratings.

1. Efficient Fuel & Engine Management
   • Monitor and optimize Specific Fuel Oil Consumption (SFOC).
   • Ensure proper fuel treatment and purification for complete combustion.
   • Maintain injection timing, exhaust valve operation, turbocharger efficiency, and other combustion parameters.
2. Machinery Maintenance & Reliability
   • Implement Planned Maintenance System (PMS) to keep engines, boilers, pumps, and auxiliaries in top condition.
   • Minimize performance losses and prevent fuel wastage due to poor maintenance or breakdowns.
3. Energy Saving Measures
   • Operate waste heat recovery systems effectively.
   • Ensure efficient use of shaft generators, economisers, and energy storage systems.
   • Coordinate with the deck department for trim optimization and ballast water management.
4. Monitoring, Recording & Reporting
   • Ensure accurate logging of fuel consumption and emissions data (essential for CII, IMO DCS, and EU MRV).
   • Provide reliable data to the Chief Engineer and Master for voyage optimization and compliance.
5. Crew Training & Awareness
   • Train engine room staff in energy-efficient practices (e.g., avoiding unnecessary running of machinery).
   • Encourage a fuel-conscious culture onboard.

• GHG ratings such as EEDI, EEXI, and CII are now key industry standards that influence both regulatory compliance and commercial viability of ships.
• The Second Engineer plays a pivotal role in maintaining propulsion efficiency, optimizing auxiliary operations, and ensuring accurate reporting.
• By being proactive, the Second Engineer contributes to compliance, reduced fuel costs, improved GHG rating, and enhanced market value of the vessel.