“Fire on the water, smoke in the sky”
Author: Sudhanshu Sarronwala, Chief Impact Officer at Infarm
In March 2021, residents of Bengaluru in India, living around Bellandur lake, witnessed their beloved lake in flames. Strangely enough, this bizarre event was not new to them. It had happened twice before: First in May 2015 and then in January 2018. The first two were attributed to the presence of pollutants in the water. This time, it was the burning of a garbage mound in the buffer zone.
Which brings me to the question: is setting a massive lake on fire possibly the worst thing we can do to our precious bodies of water? I guess you won't be surprised if I argue that the answer is no. Let me take you back to August 2014, when more than 400,000 residents of Toledo, Ohio, were left without potable water for two days due to the high level of toxins found in Lake Erie.
The sad truth is, we don't have to go back as far as 2014. Unfortunately, unlike our freshwater supply, we have more than enough examples of water contamination. Just ask the volunteers who helped remove 40 tonnes of dead fish that washed up on the shores of Lake Litani in Lebanon last year.
I reflect upon all these catastrophic events in the context of two milestones this year. The first is the 50th anniversary of the Clean Water Act, and the second is a recent study indicating that the green water planetary boundary has been transgressed. Sad irony.
The boundaries we mustn’t cross
The fascinating concept of the nine "planetary boundaries" was first introduced in 2009 to represent Earth's system processes, which create dangerous levels of uncertainty beyond certain points if crossed. Today we recognise the following: Land-system change, Freshwater use, Biogeochemical flows (nitrogen and phosphorous cycles), Biosphere integrity, Climate change, Ocean acidification, Stratospheric ozone depletion, atmospheric aerosol loading, and Introduction of novel entities.
Although still essential for our survival, conventional agriculture is one of the major forces pushing our planet's systems over some of these boundaries. The link between traditional agriculture and boundaries, such as Land-system change or Freshwater use is quite intuitive. Other correlations are far less clear and, therefore, less talked about.
That's why I would like to dedicate this blog post to Biogeochemical flows and focus on nitrogen (N) and phosphorus (P) cycles. Two elements that are critical for life and essential for plants' growth.
The process that changed the world
At the beginning of the 20th century, with the increasing demand for nitrogen-based fertilisers, it became clear that neither guano nor the reserves of nitre deposits could satisfy the growing demand. As a result, all over the world, chemists tried to convert atmospheric nitrogen to ammonia. After all, almost 80% of the air we breathe is nitrogen.
The first person who produced ammonia from the air at a laboratory scale was a German chemist named Fritz Haber. But it was Carl Bosch who managed to scale it up to industrial-level production. Bosch and Haber were awarded Nobel prizes and earned their place in history.
It's hard to grasp the magnitude of their contribution to humanity: the Haber-Bosch process enabled humanity to grow from 1.6 billion people at the beginning of the 20th century to close to 8 billion today. As of 2022, more than 90% of ammonia is produced through this method. In fact, almost half of the nitrogen in our body tissues originated from this process. All of this, of course, is not without consequences. For example, ammonia, produced via the Haber-Bosch process, is the most energy-intensive commodity chemical, responsible for 1%–2% of global energy consumption and 1.44% of CO2 emissions. To put it into context, the airline industry is responsible for 2.1-2.4% of global emissions.
A word about Phosphorus
Unlike nitrogen, the Phosphorous required to produce fertilisers is not created but mined in the form of rock phosphate. These days, the global supply chain consumes almost 90% of P, mainly used to produce fertilisers. And according to recent estimations, at the current rate, our existing rock phosphate reserves could be exhausted in the next 50-100 years.
What we need to understand is that the rate will not remain constant since it's projected to increase by 50-100% by 2050, with the increase in Earth's population. But long before we exhaust our rock phosphate mines entirely, we must remember that even a slight shortage, followed by a price increase, would probably significantly affect global food security. Phosphorus based fertiliser prices have increased over threefold since the beginning of 2020, and we can all feel it in our pockets whenever we go to the supermarket.
N & P: the lethal duo that gives us life
Now let's go back to Toledo, Ohio. Remember the toxins found in lake Erie? These toxins were attributed to the proliferation of algal blooms, which was related to the overflowing of nitrogen and phosphorus, mainly from runoff from over-fertilised fields. This phenomenon is called eutrophication or “nutrient-induced increase in phytoplankton productivity”. In this process, as the water becomes enriched with N & P, algae grow at an exponential rate. As a result, the amount of oxygen and light available for aquatic life is decreased. Runoff from fertilised fields is the No.1 source of excessive nutrients. Another phenomenon of pollution is the 'leaching' of nutrients. Nitrogen (most notably) is a nutrient that, when given in excess, leaches into the soil beyond the root zone and contaminates the groundwater aquifers underneath.
In fact, N&P pollution is one of the world’s most challenging environmental problems. All this, without mentioning the devastating effect excessive N&P have on the soil quality, air pollution, biodiversity… the list goes on. So, it is no surprise that the estimated annual cost of pollution by agricultural nitrogen use in the EU was between USD35-230 billion a year, while potential damages from agricultural nitrogen in the US were estimated at between USD59-340 billion.
In short, we chemically convert more atmospheric nitrogen into reactive forms than all of the Earth's natural processes combined. Rather than taken up by crops, much of this new reactive nitrogen is emitted into the atmosphere, pollutes waterways and coastal zones, and accumulates in the terrestrial biosphere. Similarly, a relatively small proportion of phosphorus fertilisers is taken up by plants. Eventually, much of it also finds its way to aquatic systems, turning them into oxygen-starved bodies (hypoxia) as bacteria consume the algal blooms that grow in response to the high nutrient supply. The environmental costs are getting higher, just like the fertiliser prices, which as of 2022, are at a record high. Surely, all this has got to stop!
Promising solutions, disappointing results
It goes without saying that the best brains in the world have been trying to tackle this devastating problem over the years. The solutions range from exploring new rock phosphate mining areas to inventing novel, more sustainable ways to produce ammonia. So far, none of them has yielded satisfying results.
Fifty years after the Clean Water Act was passed, more than 100,000 miles of rivers and streams, close to 2.5 million acres of lakes, reservoirs and ponds, and more than 800 square miles of bays and estuaries in the United States alone have poor water quality because of nitrogen and phosphorus pollution. To realise the severity of this phenomenon, I would recommend this global map of coastal areas impacted by hypoxia and/or eutrophication.
I believe that one of the most sustainable solutions we have today is hiding under the LED lights at vertical farming growing facilities.
The next revolution will be vertical
As argued in “modern tools for a modern food system”, shifting humanity from its current trajectory will require a gamut of revolutions. This is especially evident when looking at the state of the Earth through the lens of the planetary boundaries. When focusing solely on N&P, we can immediately see why.
Firstly, the growth cycle of VF crops is much shorter and the crop productivity of vertical farming is much higher when compared with conventional agriculture. Also, fertiliser consumption correlates with water consumption, and for example, at infarm growing centres, we use 95% less water than conventional agriculture.
Secondly, in the vertical farming industry, we constantly monitor the nutrient concentrations in the water. And whatever the crops don’t use will be used for the next irrigation cycle. In other words - we recycle the nutrient solution instead of discharging it into the environment, and only the necessary amounts of nutrients are used. After we irrigate our crops, the water we use is filtered, disinfected, enriched with the needed nutrients, and stored back in the water tank, ready to be used upon plant demand.
But perhaps the most significant advantage is that we simply don’t cause runoff. The water we use is recycled repeatedly at every irrigation cycle and leaves the system only when it is time for maintenance. Even then, we don’t just flush it down the drain. During maintenance and before discharge, the water is lab-tested and treated to ensure that it abides by municipal regulations concerning harmful residue levels of chemicals.
So, not only do our solutions specifically target the exact plant requirements, but we also make sure that any excess can be safely disposed of.
That is the miracle of vertical farming. That is the future of our food production.
When reflecting on planetary boundaries, we have no choice but to keep pushing the boundaries of agriculture.
Special thanks to Yotam Guetta, Penelope Galarza, Pádraic Flood, Hassan Awada, Arnavaz Schatten, Viviana Andrea Correa Galvis and Oded Pshetatzki for assisting in writing this article.