Managing the nitrogen used to grow food and moving to sustainable food systems can reduce air, soil, and water pollution and protect the climate, writes Olga Algayerova, Executive Secretary, United Nations Economic Commission for Europe (UNECE).
With the Food Systems Summit taking place in a couple of weeks under the auspices of the UN General Assembly (23 September 2021), we need to face an uncomfortable truth – that the food systems we have built over recent decades are unsustainable and the food choices we make every day are having a large impact on our environment, human health, societies, air quality and climate change.
Writing on the International Day of Clean Air for Blue Skies, I want to focus on one aspect of the food system: nitrogen. Nitrogen is a central element to our food systems as it links air quality, soils, water and food. Nitrogen (N) is an element of chlorophyll in plants and of protein (amino acids) in animals and humans.
Over the past 100 years, humans have massively altered flows of nitrogen on our planet, leading to both benefits for food production and multiple threats to our health and the environment. The use of fertilizers and the production and use of manure in agriculture lead to significant nitrogen emissions to air and releases to water and land. Among its dire consequences are greenhouse gas emissions and air, soil and water pollution that damage human health, threaten biodiversity of forests and rivers, and lead to coastal and marine pollution that exacerbates the effects of climate change.
Globally, two thirds of nitrogen pollution come from agriculture. Livestock production is the biggest culprit. More than half of the nitrogen poured onto fields is washed from fields into rivers, exhibiting huge inefficiencies. Earth system scientists say that the world’s planetary boundaries for interference with the nitrogen cycle have already been surpassed. It is now recognized by the international community that if we do not halve the number of nutrients, including nitrogen, we dump into the environment by 2030, our ecosystems will face toxic tides, lifeless rivers, and dead oceans.
Sustainable food systems are impossible without sustainable nitrogen management, and I am proud that guidance developed under the UNECE Convention on Long-Range Transboundary Air Pollution can inform the action we need. This can help foster a “nitrogen circular economy” and increase the efficiency of nitrogen use throughout the food system, through, for example, new technical measures in agriculture for manure management.
There are also large differences between foods in terms of nitrogen losses per unit of protein produced. Plant-based foods, such as cereals, have relatively low losses compared to livestock products. Take beef, for example. Nitrogen losses per unit of food protein from beef are more than 25 times those from cereals. Shifting towards more plant-rich diets can therefore not only reduce environmental impacts of nitrogen pollution but also reduce the adverse health impacts from consumption of (red) meat, such as the risk of cardiovascular disease and type 2 diabetes. This could also reduce the risks of zoonotic diseases originating from industrial animal rearing while freeing up substantial areas of agricultural land to help meet global food security goals.
Protein-rich legumes, for instance, have a large potential to increase protein production sustainably, while at the same time fixing nitrogen. Tapping into the full potential of cultivating a bigger variety of legumes could help meet demands, increase protein self-sufficiency of regions, and contribute to healthy diets. Of course, all approaches need to be tailored to region-specific contexts, taking into account socio-economic factors and regions where livelihoods depend on agriculture.
We also must capitalise on growing consumer interest in local and seasonal produce. Clearly, reducing food loss and waste so that more of what is produced with precious resources reaches our plates is also vital.
However, transforming our food systems is a task that transcends many policy fields. We need to make sure that we tackle the challenges in an integrated way so that we can reap co-benefits for food security, environmental integrity, health and development. There is no either-or anymore. We have to exploit all possible solutions and we have to do it now. I call on Governments to take the Food Systems Summit as an opportunity to openly discuss all of the options on the table to rethink and transform our food systems for a sustainable future.