There is a two-way relationship between food production and air pollution: food production contributes significantly to air pollution; in turn, air pollution can impact food production.
Agriculture is the single largest contributor of ammonia pollution as well as emitting other nitrogen compounds. This affects soil quality and thus the very capacity of the soil to sustain plant and animal productivity. In addition, the growing trade in agriculture products in the last few decades has further increased the amount of pollution emitted from the intensification process in producer countries. As this burden remains in the producer country, it creates an imbalance and shifts the pollution problem from the importing countries to the producer countries.
Conversely, there is increasing evidence that food production is also threatened by air pollution. Ozone precursor emissions (nitrogen oxides and volatile organic compounds) are of particular concern for global food security as these compounds react to form ground-level ozone. This, in turn, penetrates the plant structure and impairs its ability to develop. Ozone was estimated to cause relative global crop losses for soy 6-16%, wheat 7-12% and maize 3-5%. At a European level, a study in 2000 of the economic losses due to the impact of ozone on 23 crops amounted to 6.7 billion Euros.
Some crops have been found to be more sensitive than others to ozone exposure, with wheat and soybean being particularly sensitive; potato, rice and maize being moderately sensitive; whilst barley has been found to be ozone resistant. Of concern is the fact that these most sensitive crops are all staple foods for the majority of the world’s population.
Fisheries are also affected as nutrient run-off from land-based sources creates “dead zones”, degrading habitat for fish – coral, seagrasses and mangroves – and endangering fish species already vulnerable because of over-fishing and climate change. Yet, globally up to 20 per cent of human protein consumption comes from aquatic animals and fisheries are a major source of income and jobs for many communities around the world.
In a world faced with much unrest and uncertainty, global food security is an additional driver of turmoil. Research on the impact of air pollution on food is relatively recent. Yet all indications suggest that reducing air pollution benefits food production and thereby, global food security.
What Unece do
The Convention sets targets for various air pollutants that have direct or indirect effects on food production, such as sulphur, nitrogen and emissions of ground-level ozone precursors (nitrogen oxides and non-methane volatile organic compounds). In various bodies under the Convention, several aspects of the complex interrelation between air pollution and food production are being considered. For example, the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops is assessing the impacts of air pollutants, particularly ground-level ozone, on crops.
The International Cooperative Programme on Assessment and Monitoring of the Effects of Air Pollution on Rivers and Lakes assesses the degree and geographical extent of acidification of surface waters, which might end up in the oceans and affect habitat for fish. In addition, the Task Force on Reactive Nitrogen develops technical and scientific information and encourages coordination of air pollution policies on nitrogen in the context of the nitrogen cycle. Assisting countries in abating nitrogen emissions and managing nitrogen more sustainably, which has direct impacts on soil quality and will help in promoting sustainable agriculture, the work under the Task Force will help countries in achieving targets under Sustainable Development Goal 2 on zero hunger. Similarly, the work under the Convention will also assist countries in reducing marine pollution from land-based activities, particularly nutrient pollution, which is a target under Sustainable Development Goal 14 on life below water.
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