In December, University Maritime Advisory Services (UMAS) and Ricardo Energy & Environment published a new report for the Department for Business, Energy & Industrial Strategy with some alarming findings: domestic shipping fuel consumption is 250% higher than previously estimated, and as a result, the CO2 emissions are also much higher.

The findings are based on a revised modelling methodology, which estimates emissions for the UK’s National Atmospheric Emissions Inventory (NAEI) used for official international inventory reporting obligations. The increase is attributed primarily to improved activity coverage, both of existing categories, such as fishing vessels, as well as new vessel types not previously included in the calculations, like offshore industry vessels.

According to the UCL Energy Institute, who publicly commented on the findings, the new methodology is a considerable improvement on the existing one in terms of vessel coverage, fuel consumption and emission factors and it exceeds the requirements of reporting a national shipping emissions inventory under international commitments.

The findings came as a stark reminder that the UK needs to do more to improve air quality standards across the country. In March, a package of funding worth more than £260m was launched by the government to help improve air quality in some of the most polluted areas. The scheme gives funding to local authorities to encourage grassroots action in the fight against air pollution.

But while the package mainly targets road traffic, questions arise whether the government should pay more attention to the threats of shipping emissions, particularly in busy ports such as Felixstowe, Immingham, Liverpool and Southampton.

Just how polluted are the UK’s ports?

Carbon emissions from the combustion of fuels comprise about 80% of the UK’s estimate of national greenhouse gas inventory emissions, of which almost half are from sectors where rigorous regulation and reporting does not occur, the NAEI warned. Shipping is one such source of fuel oil, a heavy distillate or residual product used in very large engines.

Both nationally and internationally, campaigners have been long calling for stricter regulation of emissions from shipping, which is feared to be responsible for 17% of global CO2 emissions in 2050 if left unregulated. Last year, the International Council on Clean Transportation found that emissions of greenhouse gases (GHGs) from global shipping are on the rise again, having increased from 910 million tonnes (Mt) to 932Mt between 2013 and 2015.

In the UK, the latest findings were just as bleak. Using accurate terrestrial AIS data supplied by the Maritime and Coastguard Agency, UMAS revealed that the CO2 emissions for domestic shipping are four times higher than previously estimated. An increase of 3.7Mt CO2 equivalent was recorded, up from the existing estimate of 1.4Mt published in 2014.

“UMAS revealed that the CO2 emissions for domestic shipping are four times higher than previously estimated.”

Existing estimates for fishing vessels, for example, assumed zero fuel oil consumption, and just 47,000t gas oil consumption. The new study reveals that these vessels in fact consume 201,000t of fuel, reflecting commensurate CO2 and CH4 emissions, as well as higher than anticipated increases in NOX, N2O, PM10 and SO2 – all dangerous pollutants to human health. An additional 4.4Mt of CO2 emissions were calculated to originate from other, non-fishing vessels stopping at UK ports.

“This work shows that the UK’s efforts to decarbonise and improve air quality must include domestic shipping,” said Dr Tristan Smith, director of UMAS and reader in Energy and Shipping at the UCL Energy Institute. “Not only does this study show that we formerly underestimated the significance of domestic shipping, but reinforces the concern that without action this sector will become an increasing share of UK’s GHGs.

“The sooner we understand the air quality implications, particularly in port cities, of domestic shipping, the sooner cost-effective and sustainable strategies to address the coupled GHG and air quality issues can be developed,” he added.

How are port emissions being addressed?

Speaking at the Smart Shipping Event in February, UK transport secretary Chris Grayling told an audience of representatives from across the shipping sector that the country’s maritime industry is on the verge of a technological revolution that could make shipping faster, safer and more environmentally friendly. He referenced the rise in the number of electric and hybrid vessels entering operation, as well as the ongoing development of low or zero emission fuels as encouraging trends towards curbing pollution.

Grayling’s speech came just five months after the government pledged over £6m in funding trials of innovative technologies and fuels to reduce maritime emissions, such as state-of-the-art propellers, on board waste heat recovery, and rotor sails that use wind power to cut fuel consumption.

“The UK already has several hybrid ships operating in its waters,” a government press release read. “These systems offer local air quality benefits, can be quieter for port communities and provide opportunities for further energy efficiency on board a vessel.” By 2025, the government estimates that the majority of new ships will be expected to be 30% more efficient than current designs.

Efforts coming from individual port authorities are equally noteworthy.

Last year, the Port of London Authority (PLA) marked a first in the maritime sector by publishing a draft Air Quality Strategy for a UK port. The aim of the strategy, which covers the tidal Thames from Teddington Lock to Southend, focuses on reducing emissions from marine sources within the tidal River Thames. The move came less than 12 months after the PLA made London the first UK port to offer a ‘green’ discount on charges for ships using cleaner technology.

“The Port of London Authority marked a first by publishing a draft Air Quality Strategy for a UK port.”

“The Thames Vision sets out how use of the river will grow over the next twenty years,” said PLA chief executive Robin Mortimer at the time. “Our commitment in the Vision is that this growth will happen in tandem with an improving environment.”

Similarly, the DP World London Gateway Port confirmed last year that it reduced its carbon emissions by 28% per TEU in 2016. This was achieved through the introduction of hybrid-electric shuttle carriers, better recording and tracking of energy use, and reduced energy consumption in buildings.

Going forwards, the British Ports Association has launched a new Port Futures project, which will address key issues for ports over the next 50 years, with climate change and the environment an integral part of the challenges faced by UK ports in the years to come.

Similarly, new guidance from the UK Chamber of Shipping published in March comes in the form of an Environmental Resolution, encouraging its members to push for greener operations – be it that they eliminate irresponsible practices, reduce pollution as much as they are able, or develop further research, training and in-house policies to address concerns.

“We hope that our Environmental Resolution sends a clear message that, fundamentally, it is simply not necessary to pollute the environment in order to run a profitable, productive shipping business,” a Chamber press release read. “There is no need to operate vessels in a way that will damage the world’s flora and fauna or endanger human health.”