Yokohama to Seattle freight CO2 emissions
One tonne of cargo shipped Yokohama (JPYOK) to Seattle (USSEA) by sea emits 58.5 kg CO2e well-to-wake at GLEC v3.2 default factors. The same tonne by air emits 4,681.6 kg — roughly 80x the sea number.
Lane noteShortest of the trans-Pacific container lanes by sea miles. Great-circle routing across the North Pacific gets ships into Puget Sound in 9-11 days at 18 knots; Seattle is a Toyota and Subaru inbound hub.
Per-tonne CO2e by mode
Sea freight
Container ship 8,000-12,000 TEU
- Distance
- 7,800 km
- Factor (WTW)
- 7.5 g CO2e/tkm
- Per shipment
- 1 t × 7,800 km
- Factor source
- GLEC v3.2 container 8,000-15,000 TEU (Post-Panamax, WTW)
Air freight
Long-haul belly cargo
- Distance
- 7,700 km
- Factor (WTW)
- 608 g CO2e/tkm
- Per shipment
- 1 t × 7,700 km
- Factor source
- GLEC v3.2 long-haul belly cargo allocation (WTW)
Mode comparison
On the Yokohama to Seattle lane, air freight emits about 80 times more CO2e per tonne than sea freight at GLEC v3.2 defaults. The gap is driven by the WTW factor difference between long-haul belly cargo (608 g CO2e/tkm) and a Container ship 8,000-12,000 TEU (7.5 g CO2e/tkm), partly offset by the shorter great-circle air routing.
Try this in the calculator
These numbers are GLEC v3.2 defaults at 1 tonne. Change weight, vessel class, or load factor in the calculator and see the per-mode CO2e update under ISO 14083:2023 data quality tiers.
Methodology references
- Methodology — GLEC v3.2 emission factors and ISO 14083 data quality tiers
- GLEC v3.2 in practice — three worked emission calculations
- Per-class container ship CO2 factors by TEU range
- What changed in GLEC v3.2 vs v3.0 and v3.1
- Glossary — WTW vs TTW vs WTT, ISO 14083 data quality tier definitions
- The 2026 State of Freight Emissions Report
- All trade-lane CO2 pages