Sail-powered cargo ships are making waves on the seas. High-tech versions of old tools are being installed on existing cargo ships in order to reduce fuel costs and help decarbonize the industry, which currently generates 3% of all human-created greenhouse gasses. Retrofitting cargo ships with sails could make maritime shipping greener and cheaper, and even change how the complicated shipping industry works. WSJ host Danny Lewis reports. What do you think about the show? Let us know on Apple Podcasts or Spotify, or email us: FOEPodcast@wsj.com Further reading: Old-School Wind Power Is Back for Cargo Shipping  Shipping Regulator to Steer Clear of Stricter Rules on Carbon Emissions  Fertilizer Companies Are Betting on Ammonia as a Low-Carbon Fuel  Learn more about your ad choices. Visit megaphone.fm/adchoices