The environmental performance of container ships has deteriorated but the wider shipping sector is heading in the ‘right direction’, a new study finds.
Reduced time at sea and speeding up of vessels led to a decline in the environmental performance of boxships, according to German ratings agency Scope.
The proportion of container ships with a Carbon Intensity Indicator (CII) rating of A fell by 2.2% to 323 vessels between 2019 and 2021.
That resulted in a 3.5% decline to 59.3% in the proportion of more than 5,000 container vessels it measured that had ratings of between A-to-C.
Carbon emissions of boxships increased as vessels speeded up to cope with increased demand, or were forced to wait at anchor with engines running.
“The latest data show how much the environmental performance of certain ship types has deteriorated in the volatile context of the pandemic and the recovery in trade volumes in its aftermath,” said Scope Group managing director Ralf Garrn.
“Reduced time at sea due to pandemic-related travel restrictions led to a decline in the environmental performance of passenger vessels such as ro-ro vessels and cruise ships, as they burned fuel idling in ports,” he said.
“A ship’s CII results will always worsen if it does not sail for long periods.”
Passenger vessels including cruise ships also saw their green credentials deteriorate.
The number of ro-ro vessels with an A rating decline from 375 in 2019 to 107 in 2021.
Some 36,921 vessels of all types required a CII rating and their overall performance has improved, Scope notes.
The number of ships with a ranking of between A and C rose by 3.4% to 66.7% from 2019 to 2021.
Vessels requiring D and E rating declined by 2% and 1.3% respectively, compared to 2019.
The best-performing segment was the tanker sector which registered a 13% increase in A to C ratings to 77% in 2021.
Gas carriers saw a 10% increase in A to C ratings to 80%.
Bulkers with an A to C rating dropped 3.1% over the period.
Under rules drawn up by the International Maritime Organization (IMO), ships will be awarded a carbon intensity rating, which runs on a scale of A to E.
Ships must attain a C rating to avoid compulsory remedial action.
Ships rated D for three consecutive years or E in any year must submit plans to show how they plan to achieve a CII rating of C.