Salt Ideas essay #6: How do we feed 9 Billion mouths by 2050?


We’re proud to bring you the sixth of the Salt Ideas Essays: 15 pieces of expert thought leadership on the innovations and ideas that will change the world for the better. Agriculture is set to be one of the biggest losers of climate change, but there are ways of producing food that can work for both our people and our planet. By Dickson Despommier, Microbiology profession, Columbia University.

In 1964, Bob Dylan, America’s most iconic folk singer, wrote the prophetic song, “The Times They Are A Changin’”, a lyrical warning to all the business-as-usuals that things ain’t what they used to be, nor will they ever be again. He could not have been more on the money. Today, we would all agree (well, almost all of us would concur) that what’s changin’ most is the climate. It has already affected where and how we grow our food, and has even altered where we may choose to live.


Climate change has trashed some agricultural systems and favoured others, raised the oceans and redistributed sea life. Climate change will become the mantra for generations to come, as ocean levels rise above most coastal cities, driving perhaps billions of people to seek refuge inland, encroaching on already stressed-out farmland. Agriculture will take the biggest hit of any human activity, as average summertime temperatures probably will routinely exceed 40C. Droughts and floods will become more severe, adding to farmer woes. Food shortages followed by food riots may become the norm if nothing changes. Without food and safe drinking water, we will die. Extinction is the rule in nature, and we may well succumb to that same fate if we do not act soon.

Since extinction of Homo sapiens is unthinkable (sadly we are less concerned about the extinction of every other life form on Earth), things must change. We must also be the engine for that change. The human species is superbly designed to solve problems that we ourselves have created. Our ability to think through an issue and come up with novel solutions is what got us to this point in our evolutionary history. We are not about to stop trying now just because we think the sky is falling. Our biggest immediate issues involve creating a sustainable supply of essential resources: freshwater and food top the list of needs.

If we could find ways to grow most of our soil-based crops in another way that at the same time saved on freshwater, then there might be a chance to dodge another bullet fired from Nature’s arsenal of environmental impediments.


Controlled environment agriculture (CEA) is a viable solution to establishing a sustainable supply of both of these needs. The employment of hydroponics and aeroponics to indoor growing systems located inside greenhouses and vertical farms has already provided abundant evidence that copious amounts of certain crops (leafy green vegetables, tomatoes, strawberries, and the like) can be grown with minimal use of energy and water. The concept of “closed loop” agriculture is now well established. I predict that it will become commonplace over the next 10 years, as it already has in Japan, Taiwan, Singapore, Korea, and the American Midwest.

Every day, new vertical farms open to the public, supplying food crops year round inside the city limits. As word spreads about the easy and low cost of operation, more examples will come online around the world. Food systems will readjust as the advantages of CEA become the norm for most soil-based crops. Given the current rate of success for vertical farming – most vertical farm companies in the USA are in expansion mode as of the fall of 2015 – expectations for a brighter future are high.

Food will travel less, be fresher, and hence be more nutritious than the same outdoor-grown crops that must first be picked before ripeness, and then shipped thousands of miles to market. The end result may well be a universal adoption of CEA as the main method for providing food-on-demand for some nine billion of us. An unintended consequence would be the eventual self- repair of countless damaged ecosystems originally sacrificed to make more room for farmland. It is win, win, win, win, and so on, for every single species on planet earth.


  • Hydroponics and aeroponics in vertical farms can grow copious amounts of crops with minimal use of energy and water.
  • Vertical farming could become commonplace over the next 10 years, as it already has in Japan, Taiwan, Singapore, Korea,and the American Midwest.
  • This system could allow for the repair of countless damaged ecosystems originally sacrificed to make more room for farmland.
About Dickson Despommier
Dickson Despommier is a vertical farming expert and emeritus professor off microbiology and publlic health, Columbia University, New York.