In North America alone, 82% of the population live in urban areas and the percentage is projected to grow even bigger in the coming years, as the trend in the graph below shows.[1] The increase in general population size and urban population, will be accompanied by an increase in demand for food especially in urban areas. In fact, it is estimated that the food production in developed countries must increase by 59% to 98% to meet the needs of the population in 2050 considering the current trends in population growth.[2]
To satisfy the increasing demand for food, it is only inevitable that more uncultivated land be converted into farmlands at a faster rate if no alternative methods of farming supplement the current conventional farming. Given the adverse effects of fertilizers, herbicides and pesticides used in conventional farming on microbes in the soil it is only reasonable that more species that live in the soil and in water bodies will significantly reduce in population.[3] Consequently, most ecological cycles like the carbon cycle and nitrogen cycle, and nutrient recycling are adversely affected as the population of the organisms that initiate the processes are decimated.[4]
Moreover, energy produced from renewable sources is increasing at a rate faster than ever before. In 2018, the energy produced from renewables had increased 100% from the amount it was in 2000, and is expected to reach 45% of the total energy consumption in the US by 2040. The increased use of renewable energy and exploitation of natural light in the more recent models of rooftop farming will significantly lower the carbon footprint of hydroponic and aquaponic systems.
In the long term, more chemical inputs will be required to maintain reasonable crop production, eventually compromising the productivity of the farmlands leading to demand for even more land. In light of the current situation, attention is slowly shifting to sustainable agricultural practices. Sustainable agriculture encompasses agricultural practices that aim to meet the society’s current food and textile needs without compromising the ability of future generations to satisfy theirs too by limiting the damage with which modern agricultural practices have come to be associated, like loss of biodiversity.
Hydroponics, Aquaponics, and Rooftop Farming as Alternatives and Supplements to Conventional Farming
Admittedly, the variety of crops that can be grown in hydroponic and aquaponic systems are currently limited to mainly fruits and vegetables. But in an era where people are more aware of what they eat like never before, the emphasis on eating healthy is likely to see a dramatic increase in the demand for vegetables and fruits in the future as predicted by a research done by John Kearney, a professor of Biological Sciences at Dublin Institute of Technology.[7] This is where hydroponic systems, aquaponic systems and rooftop gardens come in to the rescue as they not only guarantee high quality produce, but also produce that is almost entirely free from pesticides and herbicides.[8] The main obstacle that currently faces hydroponic and aquaponic farming is the significant energy consumption by indoor aquaponic and hydroponic systems, most of which is generated from fossil fuel plants operating on coal, natural gas and oil. However, it has been shown that hydroponic and aquaponic systems that are located on rooftops consume up to 75% less energy because they do not require artificial lighting.[9] In addition, the rooftop farms could easily be modified to harness rainwater in areas where rain is available, besides attracting insects thus improving the biodiversity of urban ecosystems.[10] In times of unfavourable weather, green rooftops could be adopted to regulate the conditions of the plants while keeping energy consumption to a minimum.
The increased use of renewable energy and exploitation of natural light in the more recent models of rooftop farming will significantly lower the carbon footprint of hydroponic and aquaponic systems. The amount of energy produced from renewable sources is increasing at a rate faster than ever before as illustrated in the graph below. In 2018, the energy produced from renewables had increased 100% from the amount it was in 2000, and is expected to reach 45% of the total energy consumption in the US by 2040.[12] Together with the almost non-existent direct pollution the systems have on the environment, these systems are, by combining effort with conventional farming, in a position to lessen the adverse effects new acreages of conventional farms would have on species living in both water bodies and in the soil.
With an increasing population and a soaring demand for food at crossroads with global warming and a rapidly plummeting biodiversity, it becomes imperative to find alternative ways to ensure our food security while protecting biodiversity on which we depend on for our ecosystems to function, even if this involves tradeoffs. For instance, open rooftop farming directly improves the biodiversity of the nearby ecosystem by attracting pollinators and even birds that feed on the insects. With the advent of renewable energy, sustainable farming methods like hydroponics and aquaponics provide us with an opportunity to increase food production in a way that does not harm the ecosystem thus minimizing the urge to extend farmlands into biodiversity hotspots, areas that are rich in wild fauna and flora.