The cruise industry is going green – but is it moving quickly enough?

How bright is the environmental future for cruise lines? (Picture: Shutterstock)


Nothing is more important than the future of our planet, and, with global temperatures rising, the race is on to find sustainable, net-zero ways of doing things normally reliant on fossil fuels – such as travel.

Though the cruise business makes up only a tiny fraction of the marine sector, it has been at the forefront of developing more environmental ways to design and operate vessels.

Today, the industry body CLIA – covering lines with 267 ships – releases an annual report by Oxford Economics on its ambitions to achieve net carbon-neutral cruising by 2050. Here I take a look at the policies and if they go far enough…

Pioneer: P&O Cruises ship Iona is one of four in the world currently running on LNG (Picture: P&O Cruises)

Alternative fuels

Ships running on liquefied natural gas emit almost no sulphur, between 95 to 100 per cent fewer particulates, 85 per cent less nitrogen oxide and up to 20 per cent less greenhouse gas compared to heavy fuel oil.


Twenty-two ships are on order with the technology. CLIA found that 52 per cent of new-build capacity will rely on LNG for primary propulsion.


So far, four ships are running on LNG.


There is a lack of LNG bunkering facilities around the world, though this is improving. Other alternative fuels being developed include biodiesel, methanol, ammonia, hydrogen and electric batteries. The report notes that there remain ‘engineering, supply and regulatory hurdles before the large-scale adoption of such fuels can take place’. With the clock ticking towards a carbon-zero deadline, there might not be time to develop the technology (other than LNG) sufficiently to be able to build the ships in time, though it’s possible that hydrogen could be used to make synthetic LNG.


Exhaust gas cleaning systems – generally known as ‘scrubbers’ – cut emissions of sulphur oxide by up to 98 per cent, halve the amount of particulates released and reduce nitrogen oxides by up to 12 per cent.


Almost all – 94 per cent – of new ships not running on LNG will have scrubbers installed.


Already, ships making up more than 76 per cent of global capacity use the technology to meet or exceed air emissions rules.


Critics say scrubbers merely transfer the pollution from the air to the water by capturing the emissions which are then dumped at sea. CLIA says it abides by all international, national and regional regulations. One of its maritime policy experts, Donnie Brown, told me: ‘A number of studies by independent parties have looked at this in the context of different waterways and have determined that [discharges] both comply with the requirements set forward by regulators and that they do not harm the environment in which the ships operate.’

Plug-in: This equipment at Southampton port allows ships to connect to the mains (Picture: Port of Southampton)

Shoreside power

Plugging into shoreside electricity supplies (ideally those fed by renewable sources, such as wind and hydropower) means ships’ engines can be turned off in port, eliminating emissions.


Four in five (82 per cent) of new ships will be fitted with shoreside power connectors.


So far, around a third of ships (35 per cent) have the technology and 22 per cent will be retrofitted.


Only 14 ports in the world offer the facility – and then, not at all quays. The European Commission has proposed a zero-emissions requirement on docked passenger ships by 2035. CLIA’s director general Ukko Metsola told me: ‘It’s true that we only have a very small number of ports with shoreside capacity in Europe but I suspect it will change, not as quickly as we would hope for, but it will improve quite dramatically over the next ten years.’

Wastewater treatment

Filters and other technology ensure effluent discharges reach the standard of shoreside facilities and go well beyond international requirements.


Every new ship will be equipped with advanced wastewater treatment systems.


Around three in four (74 per cent) already have the technology.


That still leaves around a quarter of the current fleet without the systems, though all ships must still apply to international rules on discharges.

What CLIA says

‘Cruise lines remain at the forefront of the challenge to develop new environmental technologies which benefit the entire shipping industry,’ says Kelly Craighead, president and CEO of CLIA. ‘Our industry is committed to pursuing net carbon-neutral cruising by 2050, and CLIA and our ocean-going members are investing in new technologies and cleaner fuels now to realise this ambition.’

Pierfrancesco Vago, chairman of CLIA Global, adds: ‘We know that there is more to be done but the cruise industry has shown both its commitment and its capability to rise to the challenge. The cruise industry is an enabler of green maritime innovation, which will be the key to decarbonisation of shipping. This is why CLIA has joined other maritime organisations to propose a $5billion IMO (International Maritime Organisation) research and development fund to accelerate the development of zero GHG (greenhouse gas) fuels and propulsion technologies.’

More on the CLIA environmental initiatives here

Conclusion – a personal opinion by Dave Monk (Shipmonk)

I have no doubt about the sincerity of cruise line bosses to reduce the environmental impact of their ships. A lot of time and money has gone into cutting emissions, finding alternative fuels and treating wastewater. But with the severity of the climate change crisis being highlighted by the COP26 conference in Glasgow, these key moves should be considered:

More transparency. The cruise industry needs to be open, honest and clear on the challenges it faces – and be ready with facts and figures to answer the critics.

More urgency. All new ships should have to comply to an agreed set of environmental standards and existing fleets should be retrofitted as far as possible with the greenest technology.

More pressure on ports to instal shoreside power. It’s shameful that only 14 ports in the entire world are equipped with the technology, which could substantially cut ship emissions when docked. New installations need to be speeded up and rely on renewable sources wherever possible.

What’s your view? Please leave your comments below

Related materials

Infographic on the report

Detailed grid of the findings

The full report

Leave a Reply