Under the new climate deal, there will be 50% reduction of emissions by 2050, compared to 2008 levels.
The move comes after talks at the International Maritime Organization (IMO) in London. It will send a signal through the industry that rapid innovation is now needed.
Ships may have to operate more slowly to burn less fuel. New designs for vessels will be more streamlined and engines will have to be cleaner, maybe powered by hydrogen or batteries, or even by the wind.
Shipping generates roughly the same quantity of greenhouse gas as Germany. Like aviation, it had been excluded from climate negotiations because it is an international activity. Both the Kyoto Protocol and the Paris Agreement involved national pledges to reduce greenhouse gases.
The United States, Saudi Arabia, Brazil and a few other countries had not wanted to see a target for cutting shipping emissions at all. By contrast the European Union, including Britain, and small island states had pushed for a cut of 70-100%.
So the deal for a 50% reduction is a compromise. Some argue is unrealistic while others say does not far enough.
Kitack Lim, secretary-general of the IMO, who had chaired the controversial talks, said: “This initial strategy is not a final statement but a key starting point.”
SD Reza, our Indonesia correspondent, attended the briefing by Muhammad Lutfi, Indonesian ambassador to the US.