The world’s largest maritime shipping company is slowly ditching fossil fuels, and in doing so has thrown down a challenge for the rest of the industry to follow suit.

Denmark-based AP Moller Maersk this week said it will cut its carbon emissions completely by 2050. That’s a significant goal for the company, which is part of an industry responsible for about 3% of the world’s emissions, according to the United Nations. If shipping itself were a country, data show it would be the world’s sixth-biggest greenhouse gas emitter. Maersk accounts for about 20% of the world’s sea-based freighting.

The biggest part of the process will be to switch to carbon-neutral ships by 2030, a move that depends on the industry’s ability to find cleaner ways to power their massive container ships. “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,” says Søren Toft, a top executive at Maersk.

The company has already aggressively sliced into its carbon footprint. Since 2007, Maersk has reduced overall carbon emissions by 46%, according to the company and media reports. That’s been made possible by about $1 billion in investment into cleaner technology, including the hiring of more than 50 engineers to find those solutions.

The lofty goal set by Maersk is in line with the United Nations’ International Maritime Organization’s strategy, which called on 173 member countries to cut emissions by half from 2008 levels by 2050.

The“bunker fuel” typically used for international shipping causes problems beyond greenhouse-gas emissions. That type of fuel can have sulfur content that’s 3,500 times higher that gas used in diesel cars. Sulfur is a smog-producer and precursor to ozone, which has been linked to several health problems, including asthma, heart disease, and pregnancy complications.