Most of the clothing and gadgets you buy in stores today were once in shipping containers, sailing across the ocean. Ships carry over 80% of the world’s traded goods. But they have a problem – the majority of them burn heavy sulfur fuel oil, which is a driver of climate change.

While cargo ships’ engines have become more efficient over time, the industry is under growing pressure to eliminate its carbon footprint.

European Union legislators reached an agreement to require an 80% drop in shipping fuels’ greenhouse gas intensity by 2050 and to require shipping lines to pay for the greenhouse gases their ships release. The International Maritime Organization, the United Nations agency that regulates international shipping, also plans to strengthen its climate strategy this summer. The IMO’s current goal is to cut shipping emissions 50% by 2050. President Joe Biden said on April 20, 2023, that the U.S. would push for a new international goal of zero emissions by 2050 instead.

We asked maritime industry researcher Don Maier if the industry can meet those tougher targets.

Economics and the lifespan of ships are two primary reasons.

Most of the big shippers’ fleets are less than 20 years old, but even the newer builds don’t necessarily have the most advanced technology. It takes roughly a year and a half to come out with a new build of a ship, and it will still be based on technology from a few years ago. So, most of the engines still run on fossil fuel oil.

If companies do buy ships that run on alternative fuels, such as hydrogen, methanol and ammonia, they run into another challenge: There are only a few ports so far with the infrastructure to provide those fuels. Without a way to refuel at all the ports that a ship might use, companies will lose their return on investment, so they will keep using the same technology instead.

It isn’t necessarily that the maritime industry doesn’t want to go the direction of cleaner fuels. But their assets – their fleets – were purchased with a long lifespan in mind, and alternative fuels aren’t yet widely available.

Ships are being built that can run on liquefied natural gas (LNG) and methanol, and even hydrogen is coming online. Often these are dual-fuel – ships that can run on either alternative fuels or fossil fuels. But so far, not enough of this type of ship is being ordered for the costs to make financial sense for most builders or buyers.

The costs of alternative fuels, like methanol and hydrogen fuels made with renewable energy (as opposed to being made with natural gas), are also still significantly higher than fuel oil or LNG. But the good news is those costs are starting to decline. As production ramps up, emissions will drop further.