According to Studies, Both Old and New Solutions are Paving the Way For Net-Zero Emissions Agriculture.
- Agriculture and the food processing industry account for a third of global greenhouse gas emissions, so these sectors play a crucial role in efforts to combat the transgression of the planetary climate boundary. They also have profound impacts on freshwater systems, biodiversity, and biogeochemical cycles.
- New and emerging technologies could pave the way to zero-emission agriculture over the next two decades by employing robotics, electric vehicles, improved crop varieties, and decentralized monitoring systems, a new study shows. Precision farming could reduce emissions by 71% and help build carbon stocks on the earth.
- According to a second study, growing single-cell protein supported by solar panels could yield up to ten times more protein per unit area than growing crops like soy, reducing greenhouse gas emissions from land conversion and synthetic fertilizers.
- A third report shows that by 2050, Europe could feed an estimated population of 600 million people from organic farming alone, by reducing the consumption of animal products to around 30% of total food intake, introducing crop rotation, and reintroducing livestock and arable farming through the use of manure connects with each other.
New and emerging technologies could pave the way to zero-carbon agriculture over the next two decades, according to a study published last month in the Proceedings of the National Academy of Sciences (PNAS).
Plenty of new and emerging agricultural technologies are on the horizon that could revolutionize how we think about food production, but a separate report published in the journal One Earth suggests low-tech solutions could be just as effective.
Agriculture and food production are responsible for 34% of global greenhouse gas emissions, making these sectors a crucial factor in efforts to tackle the current transgression of the planetary climate limit. This sector also has profound impacts on freshwater systems, biodiversity, and the nitrogen and phosphorus nutrient cycles—all of which are planetary bounds that we must balance if we are to keep the Earth habitable for future generations.
But the agri-food challenge may offer a unique opportunity for climate solutions: This is because the productivity and ultimately the profitability of agri-food systems rely on photosynthesis, a process that removes CO2 from the atmosphere, and also because our agricultural land has enormous potential to become a net carbon sink and make a positive contribution to overcoming the climate crisis.
The key Role of Novel Technologies in Reducing Carbon Emissions
In a perspective article for PNAS, Daniel Northrup and colleagues compared projected greenhouse gas emissions from various agri-food technologies to actual emissions from corn cultivation.
They found that a combination of novel technologies – including digital farming, crop genetics, and electric vehicles – as part of a three-stage transition, could deliver a 71% reduction in greenhouse gas emissions from row crops over the next 15 years. At the same time, these practices target the build-up of carbon stocks in the soil, which could pave the way to net negative emissions from the sector. Both Old and New Solutions
The first phase aims to optimize the current agri-food technology using digital agriculture. This method reduces nitrogen fertilizer usage by using smaller amounts with greater precision, which could reduce emissions by 23%.
Next, existing technologies will be replaced with low-emission alternatives, including eco-friendly methods of synthesizing fertilizers and replacing fossil-fuel farm equipment with electrical alternatives powered by renewable energy. This step could involve selective breeding or genetic engineering of certain plant traits, such as B. improved nitrogen uptake by plant roots.
The final stage of agrotechnical transformation would involve a total reconfiguration of the farming system, using swarms of small farming robots to perform automated, precision farming with high-performing crop varieties controlled by placed sensors. An advanced farming system of this type could reduce carbon emissions by more than 1,700 kilograms per hectare, according to the study.
“The report focused on one of the most pervasive farming systems in the world – high-intensity corn farming – and mapped out a path to drastic decarbonization,” Northrup explained.
He argued that high-tech solutions can accelerate the transition to more sustainable crop farming that maintains vital ecosystem services like carbon sequestration and water filtration. “Because these methods can easily be used in today’s agricultural markets, they are a great start to build trust and reach agreement on sustainable [agricultural] solutions,” he said.
Livestock Decarbonization Solutions
But cultures only tell half the story, they only define half the problem and half the solution: 50% of agricultural emissions come from animal products, and here too new technologies can help.
In a separate study, also published in the journal PNAS, a team led by Arren Bar-Even from the Max Planck Institute for Molecular Plant Physiology in Germany investigated how microbial protein could be used to reduce the ecological footprint of meat production while also offering a healthy, sustainable, vegan protein for human consumption.
Since World War I, microbes have been cultured to produce protein for feed and food, and recently many companies have developed microbial systems to use this “single-cell protein” (also called SCP) as a source of animal feed, to produce fish feed and commercial food. Typically, companies use methane or agriculturally grown sugars to grow bacteria for feed and food, but the production of both substrates has associated environmental impacts. Both Old and New Solutions
However, the new study found that these effects could be circumvented by single-cell protein cultivation using solar cells. This new technology, dubbed photovoltaic single-cell protein (PV-SCP), could yield up to 10 times more protein per unit area than crops like soy, thereby reducing greenhouse gas emissions from land conversion and synthetic fertilizers.
“Engineering [and] electrochemistry are very good at certain things and biology is very good at other things, and if we take the best of both we can open up new possibilities that weren’t available before,” said the study’s lead author, Dorian Leger, who is now doing an internship at the European Space Agency.
The process works like this: Electricity from a solar farm is fed into an electrochemical unit that uses atmospheric CO2 captured from the atmosphere to create a high-energy growth medium for microbial protein, which is then converted into animal feed or used as edible protein for a variety of human food can be further purified. The protein produced is highly nutritious and meets the Food and Agriculture Organization of the United Nations (FAO) recommendations for a healthy amino acid composition and is also rich in B vitamins.
The team calculated the energy efficiency of PV-SCP and crops and found that the technique can produce 1.2 kg of protein per square meter of land per year – ten times more than the highest-yielding alternative crop, soy, which averages 0.115 kg provides protein per square meter per year. Both Old and New Solutions
The rapid adoption of this technology could mean the salvation of the Amazon rainforest and Cerrado savannah in Brazil, where vast tracts of native vegetation are converted to soy every year.
“Plants’ photosynthetic machinery is incredibly impressive, to say the least,” Leger said. “However, it doesn’t surprise me that human-designed systems can outperform it in terms of energy efficiency.”
Microbes can put most of their energy into producing proteins, while crops like soy need to invest additional energy into root systems, leaves, and other non-edible components, he explained. SCP also circumvents an important trade-off that exists in plants between photosynthesis and water loss, since microbes can be grown in closed containers where almost no water is lost through evaporation. As a result, the process safeguards another planetary boundary: our freshwater systems.
New Focus on Old, Low-Tech Farming Techniques
Despite a great deal of enthusiasm, research, and investment in new agricultural technologies, some experts believe that the same goal could also be achieved with existing, low-tech solutions. The key: a closed nitrogen cycle in agriculture.
Another new study, published in the journal One Earth, reports that by implementing three simple principles, Europe could feed its growing population, end its dependency on imported feed and achieve significant reductions in greenhouse gas emissions.
The three principles: reduce the consumption of animal products, introduce ecological crop rotation systems and restore the link between animal husbandry and agriculture through the use of manure.
“What’s surprising is that we can feed the entire population through organic farming, without synthetic fertilisers, simply by converting livestock and adjusting our diets to meet health standards,” said the study’s lead author, Gilles Billen, a biogeochemist and Research Director Emeritus at the French National Center for Scientific Research (CNRS) in Paris.
Researchers have calculated that regionally adapted crop rotation systems that directly link arable farming to livestock could meet the protein needs of 600 million Europeans by 2050 when the population is expected to have peaked.
“By using legumes – plants that are able to fix atmospheric nitrogen in proteins in their roots – as the main component of the crop rotation, a lot of nitrogen can be added to the soil naturally,” says Billen. These types of diverse crop rotations also reduce pests and diseases that thrive in the uniform conditions of agricultural monocultures, and thus reduce or eliminate the need for pesticides that address another planetary burden, pollution of novel organisms.
It’s All About the Nitrogen
Instead of relying on new technologies, Billen’s scenario envisages a return to farming principles that were commonplace a century ago but which modern agroecological know-how can now improve upon.
In Europe at that time, mixed crops and livestock farms prevailed, which used livestock manure to fertilize a diverse crop rotation, including nitrogen-fixing legumes such as clover and lucerne. These old processes were replaced by the discovery of the Haber-Bosch process in 1909. This process extracts nitrogen from the atmosphere at high pressure and temperature, revolutionizing agriculture and making cheap synthetic fertilizers readily available.
As of 2015, the Haber-Bosch process helped feed an estimated 44% of the world’s population. The catch: For every ton of nitrogen produced, the Haber-Bosch process uses a ton of fossil fuels and releases 1.87 tons of CO2. This industrial process alone is estimated to be responsible for 1.2% of global greenhouse gas emissions. Both Old and New Solutions
The irony is that after all the energy required to process the nitrogen, much of it doesn’t make it into our plants.
“When it comes to handling nitrogen, the plant-soil interface is extremely inefficient.” “Only 50% of the nitrogen we use as fertiliser ends up in our food,” Leger explains.
The remainder becomes pollution, either being washed up in waterways where it can cause harmful algal blooms or being released from the soil back into the atmosphere. It acts as a powerful greenhouse gas in this environment, with 265 times the global warming potential of CO2. Indeed, humanity’s abuse of the nitrogen cycle has already resulted in one of the most serious violations of any of the planet’s limits.
“Although this is often overlooked, our impact on the nitrogen cycle is much larger than our impact on the carbon cycle, and this depends heavily on how we produce our food,” says Silvio Matassa, a postdoctoral researcher at the University of Naples in Italy and co-author of the PV-SCP study.
“One of the most terrifying consequences of the widespread use of Haber-Bosch nitrogen synthetic fertilizers has been the ability to completely decouple grain cultivation from animal husbandry,” Billen says. Farmers concentrated on growing highly productive grain crops in the most fertile regions as production increased, pushing livestock to less fertile regions where fodder had to be imported.
“This [agricultural specialization] causes terrible dysfunction because you can’t close the biogeochemical cycles,” he explained.
Billen and colleagues were able to drastically reduce reliance on synthetic nitrogen fertilizers in favor of manure and legumes in the model study’s 2050 scenario by closely linking livestock and arable farming, resulting in a 57% reduction in nitrogen emissions.
Other sources of nitrogen waste could also be diverted to agriculture. For example, sewage treatment plants are required by law to remove nitrogen to prevent it from entering streams and rivers; after extraction, it is released back into the atmosphere as nitrogen and the greenhouse gas nitrous oxide.
“Of course, that’s completely crazy, because it’s the same nitrogen that you can reuse indefinitely with simple systems, without the energy input, and without the associated greenhouse gas emissions,” says Billen. “So it was natural for us to include [reuse of wastewater nitrogen] in our scenario.”
Reusing the nitrogen filtered from domestic wastewater in industrial agriculture could be an environmental and economic win-win since for every ton of nitrogen reused, about 2 tons of fossil fuels are saved.
Change the Diet, Change the World
The experts interviewed for this article agree that reducing the dominance of animal products in the Western diet is a necessary shift if we are to provide a healthy, sustainable and equitable diet to a growing world population.
The proportion of animal protein in the European diet has increased from 35% in 1961 to 55% in 2013, but nutritional science suggests that reversing this trend would have significant health benefits. For example, the EAT-Lancet Commission on Healthy Eating through Sustainable Food Systems recommends a reference diet with 33% animal protein. Billen’s scenario assumes a diet made up of 30% animal protein, with the rest of human needs met by grains, fruits and vegetables, and legumes such as beans, chickpeas, and lentils.
“One cannot hope to provide the entire world population [in 2050] with a diet as rich in animal protein as that found in Europe or the United States,” Billen said. “Between 30 and 40% [animal protein] is the maximum of what I call an equitable diet – a diet that can be shared by all populations of the world,” he explained.
“I’m not against ranching, and I don’t think we should do away with ranching altogether, but we probably need to find a more balanced balance than we’ve hitherto found in the West,” Leger agreed.
Currently, 30-40% of all land is used for agriculture, and yet about 800 million people – one in ten – are undernourished,” he noted. “While we anticipate that there will be problems in the food system in the future, there are already limits to what we can achieve, and despite those limits, it already has a huge environmental footprint, so we need to do something.” Both Old and New Solutions
High-tech and low-tech solutions are often considered separately, but integrating these approaches could be the fastest route to sustainable agriculture and lower carbon emissions. Imagine a future farming system that combines digital farming (e.g. automated crop monitoring and robotic fertilization) with regenerative practices (e.g. legume and intercropping-based crop rotations) and microbial protein produced using renewable energy will be added.
“I think it would be very cool if PV-SCP could be integrated into agricultural land so that it could work with crops [and] with nature so that it could share the land with insects, animals, and plants,” said Leger.
High Time For a Paradigm Shift in the Agricultural and Food Industry
A rethink of the global food system is essential if we are to meet the Paris Agreement goal of limiting the rise in average global temperatures to 1.5-2° Celsius (2.7-3.6° Fahrenheit) above pre-industrial levels. A sobering fact: Current trends in greenhouse gas emissions from our global agrifood system, assuming no change, is enough to consume humanity’s entire carbon budget before the year 2063. Both Old and New Solutions
Given the centuries of investment in the current industrial agricultural system, it will not be easy to make a radical change of course, but “there are moments in history when you are forced to change paradigms and it is now because of the urgency of the climate and of the loss of biological diversity is urgently needed,” says Billen. Fortunately, he believes the tide is beginning to turn: “I’m an optimistic person.”