How soon can we launch a fleet of clean ships?

How much do we depend on ships? Shipping is often overlooked in the mobility mix, while cars, trucks, airplanes and trains attract much of our attention. But when it comes to the economy, shipping is essential: between 80% and 90% of the world’s trade by volume is carried by sea.

Yet shipping, like other transport modes, needs to change to end its dependency on fossil fuels. The shipping industry accounts for about 2.5% of CO2emissions, or one billion tonnes of CO2annually, but along with aviation, it avoided specific emissions-cutting targets in the 2015 Paris climate accord. The current United Nations climate talks in Katowice, Poland – the so-called COP24 meeting to set the rulebook for the Paris deal – is looking at ways to cut emissions across the board, including shipping.

The sector is responding. Last April by the UN shipping agency, the International Maritime Organization (IMO), agreed to cut CO2emissions by at least 50 percent by 2050 compared with 2008 levels.

Last month, Maersk, the world’s biggest container shipper, said it aims to be carbon neutral by 2050. “The only possible way to achieve the so-much-needed decarbonization in our industry is by fully transforming to new carbon neutral fuels and supply chains,” Maersk’s Chief Operating Officer Soren Toft said.

In 2017, Maersk’s greenhouse gas emissions amounted to almost 35.5 million tonnes of CO2equivalent, mostly from its container business – but its emissions per container have been reduced by 46% since 2007. Given the 20-25 years lifetime of a vessel, Maersk says the industry has to start now to develop new types of ships that will be crossing the seas in 2050. Meanwhile, Maersk’s big rival MSC expects to pay over $2 billion a year in fuel costs due to the tougher fuel rules and will introduce a bunker charge next year to recoup expenses.

Global Shipping emissions

That’s all well and good, but it might not be enough. Global shipping emissions are predicted to increase by between 50% and 250% by 2050 – depending on future economic and energy developments, according to European Commission forecasts. The EU wants a global approach to greenhouse gas emissions from international shipping. Since the beginning of this year, large ships using EU ports have had to report their verified annual emissions and other relevant information.

The issue is complicated by the problem of sulphur in bunker fuel: when burned, it forms sulphates, which cause acid rain and pollute the air. The IMO has agreed to cut the amount of sulphur allowed 3.5% to 0.5% by 2020, a measure that could stop up to 396,000 premature deaths a year. However, the sulphates also scatter sunlight and help thicken clouds – thus slowing global warming. This cooling factor is now at risk, putting even more pressure on ships to cut greenhouse gas emissions.

Innovation is helping. Many ships’ propellers are now fitted with tip fins, which can cut fuel consumption by about 2%. Copper-based paints are being developed to drive off barnacles that slow ships. New battery and fuel cell technologies are being worked on. Even nuclear propulsion is being considered. According to the European Commission ships’ energy consumption and CO2emissions could probably be reduced by up to 75% by applying such operational measures and implementing existing technologies.

It will take time to update and clean the current fleet. But the changes are already being rolled out.