Shipping has outperformed most other industrial sectors when it comes to the reduction of carbon emissions over the last decade, according to Clarksons Research.
The shipbroker calculates that CO2 emissions for the shipping industry declined by around 14% across the period 2009-2019.
In contrast, IEA data shows that both passenger vehicle and road freight CO2 emissions increased by 20%, with growing vehicle volumes globally of 1bn to 1.6bn outweighing any fuel efficiency gains and the early stages of electrical vehicle (EV) adoption.
Similarly, aviation emissions data shows even greater growth as annual passenger numbers grew from 2.5bn to 4.6bn and air freight volumes grew by 25%.
Clarksons attributed shipping’s decline in CO2 emissions to slow steaming, a response to structural overcapacity in the 2010s with deep sea ships slowing down by 15% on average between 2009 and 2019.
There were also smaller contributions from more efficient ships with the ‘eco’ fleet rising to 18% of capacity by 2019 and projected to reach 32% by 2024 and alternative fuels.
In addition, shipping’s downward CO2 emissions trend evolved while moving 40% more cargo – 8bn versus 12bn tonnes, the shipbroker said.
Overall transportation contributes about 21% of global CO2, and within that sector, passenger traffic accounts for 46% of that total, road freight 31%, international shipping 11%, aviation 9% and rail just 1%.
Clarksons latest estimates suggest that shipping’s emissions on a tank-to-wake basis will contribute 2.1% and 822mt of global CO2 output in 2023. This is down marginally on 2022 when it was 2.3% and 845mt.
However, despite the current progress and ongoing initiatives, Clarksons said shipping’s long-term pathway seems more uncertain, particularly on fuel technology and regulation.
“For road and rail, electrification adoption and government targets are well entrenched and provide a relatively clear pathway ahead,” the shipbroker said.
For example, 14% of car sales last year were EVs, while the European Union will ban non-EV car sales by 2035.
“The aviation trade body (IATA) is suggesting as much as 65% of net zero 2050 targets will be met by ‘drop-in’ sustainable aviation fuels (i.e., biofuels) and only 13% from new technology, 19% from offsets and carbon capture and only 3% from operational and infrastructure efficiencies,” the shipbroker said.
Clarksons’ own decarbonisation scenarios for shipping suggest a mix of inputs for shipping’s pathway including slow steaming, retrofitting ESTs, fleet renewal, routing efficiencies, slower trade growth and a much larger role for alternative fuels, the ultimate choice of which is uncertain.
“Overall progress but, reflecting challenges specific to shipping, perhaps a more bumpy pathway ahead,” the shipbroker added.
