CO2 emissions from container ships fell on 10 of the world’s busiest 13 freight lanes in the first quarter, benchmarking and analysis company Xeneta has revealed.

But it has cast doubt on how much of this is down to environmental commitments by owners and how much is a by-product of commercial necessity.

Xeneta’s Carbon Emissions Index (CEI), produced in tandem with Marine Benchmark, showed the US West Coast to Asia trade corridor made the biggest emissions inroads.