They don't know how they are going to do it, but it is a bold promise.
The shipping industry has been in terrible shape for years, with far too much capacity, declining income and more expensive fuel. Many shipping companies are going bankrupt or getting bought out, often by Maersk, the world's largest container shipping company. Maersk is not just looking ahead to 2020 when bunker fuel is banned, but planning further ahead, to cut their carbon emissions to zero by 2050. According to Richard Milne in the Financial Times:
Maersk doesn't explain how they are going to do it; a few years ago we described their attempt at making fuel from algae. They are also looking at hydrogen, electricity, and wind.
“We will have to abandon fossil fuels. We will have to find a different type of fuel or a different way to power our assets. This is not just another cost-cutting exercise. It’s far from that. It’s an existential exercise, where we as a company need to set ourselves apart,” Soren Toft, Maersk’s chief operating officer, told the Financial Times.
Being a shipping company, they are not looking at another solution: reducing the number of shipping containers full of everything from recycled waste to plastic crap. One of the best ways to reduce pollution from shipping is to reduce the amount of shipping. But that is a whole other story.