How can we feed a growing world population that’s shifting toward cities? It starts with optimizing our use of land and water
As time moves forward and the world’s population increases, we must figure out a way to feed people. Currently, Earth’s population sits at around 7.7 billion, and the United Nations estimates that number to reach 10.5 billion by 2070. To feed that additional 2.8 billion people, we need a new arable land area—land that can produce crops—about the size of Brazil. And that’s not available.
So, what’s the solution? I think we need to approach agriculture differently. We can likely solve this issue by optimizing our use of land and water. Through urban agriculture techniques—like aquaculture, hydroponics, aquaponics, and vertical farming—we can create a “second green revolution,” and establish a way to feed the world’s growing population.
Before I get into those techniques, I’d like to provide some context on our current food conundrum. How’d we get here?
As the population grows, it’s going to be challenging to keep everyone fed, says Rob Simm.
The (First) Green Revolution
The Green Revolution, which took place between 1950 and the late 1960s, describes a series of initiatives that increased agricultural production around the world. As Earth’s population rapidly increased, we were able to feed people with only a 30% increase in the land area required for agriculture. Increases in agricultural productivity came from boosts in crop yields, new crop strains, fertilizers, and mechanized agriculture. But the Green Revolution came with some negative impacts, such as the effects of pesticide use on human health and the environment.
Will there be a Second Green Revolution? Will we be able to keep up with the world’s food needs by becoming more efficient through higher yield crops, and through better use of water? These are the questions that we need to be asking—now.
_q_tweetable:“Humanity’s biggest problem will likely be the fact that we won’t be able to feed ourselves.”_q_
Of course, climate change has affected agriculture in many ways. Some of the techniques used with high-yield crops aren’t working anymore, because the climate is changing. In August, the UN Intergovernmental Panel on Climate Change issued a series of reports about the impact of the climate crisis on global food security. Increased droughts, flooding, and intense summer heat mean that we need to change the way we normally approach agriculture.
While the environmental and health impacts of the climate crisis are massive and devastating—such as violent storms, freshwater shortages, worsening smog, and more—humanity’s biggest problem will likely be the fact that we won’t be able to feed ourselves.
Oceans, the North American diet, and the move to cities
Several other factors have led to our current situation. Overfishing and the acidification of the oceans—which happens from the uptake of carbon dioxide in the atmosphere—means that the stock of fishable biomass isn’t sustainable based on current fishing rates.
In addition, as more people around the world adopt a North American-style diet, people have increased the amount of meat they consume. This leads to a bigger footprint for water and carbon per person.
We also need to consider the migration toward cities and away from rural areas. While around 55% of the world’s population currently lives in urban areas, the UN expects that number to rise to 68% by 2050. How will we feed that expanded urban population?
The effects of climate change – like increased droughts, flooding, and intense summer heat – will lead to lower crop yields.
Changes in urban infrastructure
Cities are starting to look different—and that can provide an opportunity. The rise of online shopping has led to the push away from bricks and mortar retail, which is freeing up building space. The expected popularity of autonomous vehicles will likely lead to a reduction in parking spots, which will free up parking garages. So, I expect that we’re going to have a lot of new built urban infrastructure available—and perhaps we can use it for agriculture.
According to the Food and Agriculture Organization of the United Nations, approximately 10-to-15% plus of all food production in the world is happening through urban agriculture today. Of course, a lot of urban agriculture consists of rooftop gardens and communal gardens. But people are now starting to look at optimized urban agriculture within the built environment. These techniques—such as aquaculture, hydroponics, aquaponics, and vertical farming—have a much higher yield, in terms of kilograms per acre. These techniques are less water intensive, and they’re more efficient in the way we use land. Here’s a quick description of each of them.
- Aquaculture refers to the farming of fish and other sea life under controlled conditions in tanks—as opposed to the harvesting of wild fish. I’m intrigued by the idea of recirculating aquaculture systems, which recycle water by circulating it through filters to remove fish waste and then recirculating the water. This process saves water and gives farmers the option to compost the waste.
- Hydroponics let people grow plants without using soil. Plants are instead fed with a nutrient solution. Just like with aquaculture, recirculating water can reduce water use significantly. Runoff gets recaptured, and all water is reused.
- Aquaponics combines aquaculture and hydroponics systems. When fish eat and produce waste, it becomes food for bacteria, which gets converted into fertilizer for plants. This means that you’re able to grow plants in a very high yield and a very high density. Plus, aquaponics only uses 10% of the water of soil-based agriculture.
- Vertical farming is exactly what it sounds like—a technique where you can produce food in vertically stacked layers. This style of farming provides the best lighting frequency, the ultimate fertile period, and optimal temperature. The number of crops you can grow per square meter is significantly greater than what you can grow on land-based agriculture. Your farming takes up less space and you produce more food.
We need to approach agriculture differently, says Rob Simm.
A return to an agrarian society?
Aside from optimizing our use of land and water, these techniques will also put food production close to the people consuming that food—in the cities where people live. This generates a smaller carbon footprint, and as a bonus, the food will taste better because the nutrition value is higher.
I foresee a possible “back to the future” situation, where industrialized nations return to agrarian societies. But these agricultural communities will be different than what we’ve seen before, because they’ll be based upon urban agriculture, with people working in facilities dedicated to aquaculture, hydroponics, aquaponics, and vertical farming.
We’ve got to be more efficient with our land and water if we hope to produce enough food for future populations. But a push toward urban agriculture—and a possible Second Green Revolution—might be what keeps us fed.
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