By Gioietta Kuo
Senior fellow, American Center for International Policy Studies amcips.org
Nov 1 2009
Recently, UN Convention to Combat Decertification meeting in Argentina has issued a warning that drought could parch close to 70% of the planet’s soil by 2025. Currently drought is already affecting at least 41% of the planet and environmental degradation has caused it to spike by 15 to 25% just since 1990.
As we know, there is a global crisis in food and water. Our civilization is being squeezed between advancing deserts and rising seas, so that there is less and less land for feeding the growing world population which at present is 6.8 billion. Currently food and livestock are grown on land equal the size of South America. In 2050, with the forecast of population of 9 billion, we shall need an additional land the size of Brazil. Deforestation is obviously not the solution as trees are the ‘lungs’ of the planet. Already current deforestation in the world is equivalent to more than the CO2 we put in the atmosphere by burning fossil fuel.
Since 1980s, it has been realized that farming was stressing the land well beyond its capacity to support viable crops. Agrochemicals have destroyed the natural cycles of nutrients renewal that enable ecosystems to maintain themselves. We must find a sustainable way of growing food.
As urbanization continues, we are building more and more skyscrapers with walls consisting of glass and the heat through them taken away by elaborate air conditioning. What a waste of energy over a small foot print of land! On this principle, It is obvious there is much to be gained by making use of our 3 dimensional space. Why not use the third dimension for growing food by stacking greenhouses in a vertical high rise fashion?
There are many good reasons for growing crops indoors under vigorously controlled conditions:
* Food is grown in urban areas where it is eaten. There is no need to use fossil fuel to transport food from outlying areas.
* With indoor farming, there is the freedom of location, temperature, moisture content, soil composition, all fixed in outdoor farming,
* There is no runoff water into the soil. In fact water may be obtained by recycling of the vast quantity of urban waste – so call black water. Again it is produced where it is needed.
* Growing food outdoors is subject to inclement climate conditions – droughts, floods, pestilence and unpredictable crop failures. Vast quantities of water and top soil are lost in runoffs creating ocean dead zones.
* Avoidance of many life threatening parasite infections such as salmonella, cholera etc
Already growing food indoors in greenhouses is commonplace. There are three techniques which have been used worldwide:
1) Aeroponics
Plants are held in place so their roots dangle in air that is infused with water vapor and nutrients. This eliminates the need for soil. Thw amount of water needed can be 90% less than growing outdoors. Good for root crops like potatoes, carrots.
2) Hydroponics
Plants are held in place so their roots lie in open troughs. Water with dissolved nutrients is continually circulated over them. This technique is soil free and needs up to 90% less water than outdoor cultivation. Today’s greenhouses work on this principle. An example is Eurofresh Farms in Arizona which produces large quantities of tomatoes, cucumbers and peppers year round. Beside that are other market gardening produce like spinach and berries.
3) Drip Irrigation
Plants grow in troughs of lightweight, inert sheet material which can be reused for years. Small tubing on the surface rips nutrient- laden water precisely at each stem’s base. This eliminates vast quantities of water used in traditional irrigation. Good for grains like dwarf wheat and corn.
What is most significant is that by extending agriculture in the vertical direction, we can multiply our yield over that grown in the open land by a factor of 480. This can be calculated from 4 growing seasons, double stacking on each floor and 30 floors.
Finally, for mitigation of climate change, it is best to leave the land in its natural grassy and woodland state where they will naturally absorb CO2. Example of such areas abound. A good example is the Demilitarized Zone- DMZ – between North and South Korea which has over 56 years become a nature’s paradise with a profusion of animal and plant species.
For more information, consult www.verticalfarm.com. Although many planners worldwide: New York City, Los Angeles, Paris, Dubai, Abu Dhabi, Shanghai, Beijing etc have expressed interest, so far no prototype research and development farms have been initiated to answer the two main questions which are energy and water requirements. In view of the urgency of global food and water scarcity, surely it is time to jump start this striking technology which is likely to give us very high returns.