Maria Gallucci

A few years ago, I sailed on a ship that comes from an earlier era, when moving goods by sea didn't mean polluting the planet.

Our voyage through the Caribbean was eye-opening, and not just because I learned that.

Apparently, I'm incurably seasick.

I also saw what it's like when you take away the diesel fumes and the black smoke that's spewed from today's freighters and ports.

Instead, our vessels smelled like fresh sea breeze and the bags of cardamom we carried and all that chamomile tea I was chugging.

Nearly every modern cargo ship relies on highly polluting fossil fuels.

Fortunately, there's a way to clean up the industry beyond just reviving old-fashioned sailing ships.

And it's green ammonia.

If you know anything about ammonia, it's probably that it's stinky, it's toxic, it's potentially explosive.

So that's a great place to start, right?

Ammonia is mainly used today to make chemicals and fertilizers.

But for many reasons, industry experts are convinced that ammonia could be a game-changing way to drive giant cargo ships, and that it could be used safely and be cost-competitive.

Tens of thousands of freighters crisscross the oceans every day, bringing the food we eat, the clothes we wear, the cars we drive.

Container ships alone carry some $4 trillion worth of goods by sea every year.

That's roughly the GDP of Germany.

At the same time, the shipping industry contributes a significant share of the world's annual greenhouse gas emissions.

If shipping were a country, it'd be the sixth largest emitter of CO2, trailing just behind Japan.

And as world economies grow and populations rise, shipping's emissions are expected to soar, unless the industry charts a cleaner course.

So green ammonia really first came to my attention in 2017 at the UN Climate Change Conference in Bonn, Germany.

At the panel I attended, ammonia seemed kind of like an aside or something we should be keeping tabs on.