New Study Shows New Zero-Emission Ships Alone May Not Be Enough For Shipping's Climate Targets

Modifications to the current fleet may be needed to allow the shipping industry to bear down on its carbon emissions in time to hold back global warming. File Image / Pixabay

Building new zero-emission ships may not be enough for shipping to play its part in keeping global warming below 1.5 degrees, according to new research.

Existing ships currently on the water could contribute between 85% and 212% of the shipping industry's 'carbon budget' towards the 1.5-degree limit, according to an article in academic journal BMC Energy published Friday.

Any replacement or additional vessels burning conventional bunkers would add to this figure. 

"To keep within carbon budgets, the shipping sector will need not only to adopt new very low-carbon fuels and new very low-carbon ships from 2030 at the latest, but in addition rapidly deploy measures such as operational efficiency and impose slower speeds within the 2020s to mitigate the committed emissions from the existing fleet," the article's authors, led by Simon Bullock of the University of Manchester, wrote.

"Combining these measures could cut the baseline committed cumulative CO2 emissions from existing ships by up to 65%."

The article calls for 'major policy interventions' to incentivise operational changes for the existing fleet.

Slow progress at IMO

Some progress is being made towards zero-emission ships, including Maersk aiming to develop commercially viable carbon-neutral container ships by 2030.

But at the International Maritime Organization (IMO), little agreement has yet emerged on short-term measures like mandatory slow steaming to help shipping on its decarbonisation path. Those discussions have been stymied further by the COVID-19 pandemic causing several meetings at the IMO's London headquarters this year to be postponed.

"Any delay to appropriate policy implementation would mean additional measures, including demand-side or early scrappage interventions, to meet the Paris climate goals," the article's authors wrote.

"In summary, the time left to deliver on what is dictated by the global Paris Agreement is too short to rely on measures that predominantly focus on improving the efficiency of new ships.

"New zero-carbon ships are essential, but we conclude that policy makers must target a new suite of mitigation measures at the existing fleet with some urgency."