What are underwater farms? And how do they work?

Industrialized farming was once seen as a solution for a rapidly-growing global population, but it is taking its toll on the environment. The UN estimates that the world could easily be fed if just 2% of oceans were used for sustainable farming. Underwater agriculture has the potential to eliminate the need for pesticides, reduce water use and cut carbon emissions.   Image: Osman Rana, Unsplash