The world is shrinking.

Not literally, of course. When it comes to mass, our planet is the same size it’s been for billions of years. However, when one instead considers available land mass, that’s a different story.

Over the next 30 years, the world population is expected to grow by 30%. This means that by 2050, our planet will be trying to support approximately 9.6 billion people. For a world that’s already utilizing the vast majority of arable farmland, a 30% increase means that it won’t be long before earth is too small to sustain us.

Land availability is becoming an increasingly relevant issue. Not only are we using most of our farmland, we’re actually losing some of it as well. Erosion and pollution are constantly chipping away at the areas we depend on to grow our food. Studies suggest that in the past 40 years, the planet has lost 33% of its arable land.

And so, the question the world needs to ask itself is this: What land will we use to feed our growing population as farmlands decrease?

Surprisingly, the answer may not be land at all.

Water, water everywhere

Dry land isn’t the only place where food can grow. Water farming techniques in all forms — from hydroponics to aquaculture — could very well drive the future of farming.

Hydroponics is the practice of growing plants directly in water, rather than using conventional farmland. Using soluble mineral solutions, crops receive all of the nutrients they need through the water itself, without requiring access to soil. The practice can trace its roots back thousands of years to the Hanging Gardens of Babylon, but has only recently seen a resurgence of interest among modern food producers.

In the late 1920s, William Frederick Gericke, a scientist at the University of California, Berkeley, was able to grow 25-foot-tall tomato vines using only water and a solution of nutrients specifically tailored to the plant’s needs. Further research into the process demonstrated numerous advantages to soilless growing, and only a couple of decades later, troops fighting in World War II were supplied with fresh produce grown using hydroponics.

Because hydroponic farming does not require soil and takes place in an artificially controlled environment, crops can be grown in unconventional locations away from their natural habitats. Perhaps one of the most extreme examples of this is the possibility of growing food in the most non-arable climate of them all: space.

Astronauts have to eat, and, not surprisingly, the longer they remain outside of the earth’s atmosphere, the more food they need to bring with them. However, sending large amounts of food into orbit (or even farther) is no simple task. To answer these issues, NASA, in partnership with the University of Arizona is researching the practicality of using hydroponics to create space farms to feed astronauts mid-mission. Perhaps best of all, the breakthroughs they’ve achieved are not only benefiting men and women who work in space; new technologies developed for space farming may even revolutionize agriculture back here on Earth.

Benefits of hydroponics

Although space farming is certainly an extreme example, Earth-based hydroponics are just as exciting. The benefits of growing plants in unconventional locations are staggering. Food can be harvested virtually anywhere. Local populations can enjoy fresh produce without having to cover excessive transportation costs.

Crops can be grown without the need to convert forests or grasslands into arable farmland. Parts of the world that are too dry, too rocky, or too cold to support traditional farming can become more self sufficient. And, not least of all, the world’s growing population can enjoy a bountiful, alternative source of nutritious produce.

But beyond the direct benefits of hydroponics, other advantages are also worth considering. Although it may sound counterintuitive, one of hydroponics’ biggest advantages is water conservation. Hydroponic farming uses significantly less water than conventional farming.

This is because in conventional farming, much of the water used never actually reaches the plants at all — instead, it is absorbed into the soil and dispersed. Meanwhile, in hydroponic farming, water is constantly recycled in a controlled environment. Efficient hydroponics farms use as little as 10% of the fresh water required for traditional methods.

Hydroponic farming also requires less fertilizer than conventional farming, and makes it possible for farms to continue to grow the same crop year-after year without fear of exhausting soil nutrients. Finally, hydroponics crops are much less likely to fall prey to pest infestations, making pesticides unnecessary.

Don’t forget the seaweed

Traditional, land-based crops aren’t the only foods that can be grown in water. Aquaculture also has a lot to offer the world in terms of food production, sustainability, and economics.

Aquaculture differs from hydroponics in that it focuses on the farming of aquatic species. And while we may think of seafood as being limited strictly to fish and shellfish, the truth is that there are numerous plant species that can be cultivated as food for those of us who live on land.

One of the most widely farmed is actually seaweed. Like hydroponics, seaweed farming requires no fertilizers or dry farmland. Unlike hydroponics, seaweed farming also requires very little supervision or management. Seaweed’s relatively simple farming techniques and low requirements in terms of capital and material inputs make it an ideal crop for family farmers in developing nations that have traditionally relied on economies based on less-sustainable fishing practices.

Additionally, seaweed farming helps protect and preserve endangered coral reefs, and gives declining fish populations a protected habitat in which to recover. Seaweed farming is also uniquely sustainable, and can actually help reduce humanity’s carbon footprint by pulling five times more carbon dioxide from the atmosphere than land-based plants.

But can it help feed the world?

It can. Seaweed is a nutritionally dense food that is also naturally high in iodine (an often-overlooked nutrient that helps maintain thyroid health) and may help regulate estrogen and estradiol levels in the body (potentially reducing the risk of breast cancer). But even more than that, seaweed can be used to create certain beneficial food ingredients, such as carrageenan.

Carrageenan is a natural substance derived from seaweed and used in a wide variety of products — everything from cereal bars, to coffee drinks, to infant formula — to keep foods thick and homogenized. But for the problem of feeding a growing population it serves another function. Carrageenan can act as a natural preservative, resulting in increased food shelf life, and less food waste overall.

Taken together, these factors suggest that seaweed farming may play a crucial role in feeding growing populations across the world. Simply put, seaweed might be the food staple of tomorrow.

The wave of the future

The earth isn’t shrinking, but our access to traditional farmland is. If we expect to be able to feed the growing populations of our planet, we’re going to need to start thinking outside the box. Between hydroponics and seaweed farming, water could very well be the way forward for the future for agriculture, assisting with water conservation, nutrition needs, and sustainability for centuries to come.