Spanish architects have unveiled plans for floating farm factories to feed the world when the ocean takes over the land.

As sea levels rise in coming decades, Barcelona-based firm JAPA says the world will look to produce its food on the increasing expanse of ocean surface.

The company proposes a network of towers to produce agricultural products via hydroponics, with crops grow inside vertical structures that ascend and loop back to resemble a giant ribbon.

The designers say there are plenty of benefits available, including better CO2 management and reducing the distance that food must be transported.

“We used the sun as a design driver. The loop shape enables the vertical structure to receive more sunlight without having significant shadows,” Javier Ponce, head architect and founder of Forward Thinking Architecture, told the ABC this week.

Forward Thinking Architecture is the ideas lab for JAPA, and is tasked with drawing up blueprints for some serious blue-sky ideas.

Mr Ponce says the autonomous towers would be able to respond to the needs of the nearby population.

“The aim is that these vertical structures have this protocol that is based on real-time data of the city consumption, so this will help us to know the amount of food and type of food [required], avoiding a lot of food waste,” he said.

The current set of designs was specifically tailored for use near Singapore.

Singapore was picked because it has the third highest population density in the world at around 7,700 people per square kilometre, it has to import much of its food and faces serious risks from climate change and sea level rise.

The firm is planning a pilot project to see if the idea really has legs (or fins), and are waiting on approval from the Singaporean government.