CO2 emissions

What are CO₂ emissions?

CO₂ emissions are the amount of carbon dioxide released into the atmosphere, primarily from burning fossil fuels. In road transportation, CO₂ emissions come from the combustion of diesel, gasoline, natural gas, or the upstream generation of electricity used by vehicles. Because CO₂ is the dominant greenhouse gas from vehicles, it is a key metric for measuring a fleet’s climate impact and is often expressed as kilograms or grams of CO₂ per kilometer, per vehicle, or per tonne-kilometre. Practical levers—fleet management, limiting idling, and smarter routing—are central to green logistics; explore green logistics strategies to reduce CO₂ emissions for further reading.

How CO₂ emissions work in road transportation

In road freight and last‑mile delivery, CO₂ emissions depend on fuel type, vehicle efficiency, payload, driving behavior, and routing. The two main calculation boundaries are:

• Tank-to-Wheel (TTW): Emissions from fuel burned in the vehicle.

• Well-to-Wheel (WTW): TTW plus upstream emissions from fuel production, distribution, or electricity generation.

Shippers and carriers also align with greenhouse gas accounting scopes:

• Scope 1: Direct CO₂ emissions from owned or controlled vehicles (carriers, private fleets).

• Scope 3: Purchased transport services (shippers outsourcing to carriers), often reported using CO₂e (CO₂-equivalent) to include other gases.

For heavy-duty trucks, factors like aerodynamic design, tire rolling resistance, engine technology, and speed have a strong effect on CO₂ emissions. Operational choices—such as reducing empty miles, improving load factor, avoiding congestion, limiting idling, and optimizing temperature control in reefers—also significantly change the carbon profile of a trip. Reducing waiting times and engine‑on queues at warehouses through dock appointment scheduling can further reduce truck idle emissions.

Industry context

Customers, regulators, and financiers increasingly require transparent reporting on CO₂ emissions in logistics. Industry standards such as ISO 14083 provide harmonized methods for calculating and allocating transport emissions across modes and shipments. Many shippers request CO₂ emissions per shipment in RFQs and performance reviews, and carriers use these metrics to differentiate services, comply with corporate sustainability goals, and respond to carbon-based tolling or city access rules. Accurate, comparable reporting supports route planning, modal choices (e.g., road-rail combinations), and investment decisions in low‑carbon technologies like electric trucks, biofuels (e.g., HVO), or compressed natural gas where appropriate.

Key components and benefits

• Activity data: High-quality inputs (actual fuel consumption, distance, GPS traces, payload, temperature-control usage) drive accurate CO₂ emissions results.

• Calculation approach: Choose TTW or WTW consistently; declare the scope and any CO₂e gases included.

• Emission factors: Use current, credible factors for fuels and electricity mixes; update when routes or grids change.

• Allocation method: Distribute a vehicle’s CO₂ emissions to shipments via tonne‑kilometres, volume, pallets, or time; document the logic for LTL.

• Data quality tiers: Disclose whether calculations use measured fuel, telematics, or default averages; higher tiers increase credibility.

• Operational levers: Route optimization, load consolidation, backhaul planning, speed management, eco‑driving, preventative maintenance, and smart refrigeration can cut CO₂ emissions quickly. At the site level, improving dock processes to reduce drivers’ idle time also pays off.

• Strategic levers: Fleet renewal, alternative fuels, electrification for urban delivery, and driver training deliver deeper, sustained reductions.

• Benefits: Cost savings from fuel efficiency, compliance with reporting demands, improved win rates in tenders, risk management against regulation, and progress toward corporate climate targets.

Operational platforms such as Time Slot Management provide appointment scheduling that reduces idling and congestion at docks.

Real-world examples

• FTL long-haul carrier: A carrier uses measured diesel consumption and ISO 14083 methods to calculate CO₂ emissions per lane. By trimming average speed, optimizing tire pressure, and raising average payload by 8% through better planning, the carrier reduces TTW CO₂ emissions intensity (g CO₂/tonne‑km) by double digits while improving margins.

• LTL refrigerated network: An LTL operator allocates vehicle‑level CO₂ emissions to shipments based on weight‑distance, with an uplift for refrigerated stops. Nighttime deliveries, reduced door openings, and setpoint optimization lower reefer run time, cutting WTW CO₂ emissions without sacrificing product integrity.

• Urban last‑mile fleet: A retailer replaces a share of diesel vans with electric vans on dense city routes, charging with a contracted low‑carbon electricity mix. Combined with dynamic routing to reduce empty detours, CO₂ emissions per stop drop significantly, and air quality improves in restricted zones.

Conclusion

CO₂ emissions are the core measure of climate impact in road transportation, and consistent, credible calculation is the foundation for reduction. By combining accurate data, standardized methods, and targeted operational and strategic actions, shippers and carriers can lower CO₂ emissions, meet stakeholder expectations, and unlock efficiency gains across the road logistics network.