Study  provides a systematic review of the complex interactions between food systems, climate change and air pollutionIt highlights that food systems are deeply affected by climate change and air pollution, while also contributing significantly to these environmental challenges. Understanding these complex relationships is key to mitigating climate change, improving air quality, and supporting the sustainable development of food systems.

The document points out that Climate change and air pollution pose a significant challenge to global food systems. Climate change is leading to rising global temperatures and more frequent extreme events such as droughts and floods, which are severely affecting agricultural production and disrupting food supply chains. Air pollution, particularly tropospheric ozone (O3), damages plant leaves and reduces crop yields. Aerosols can have a dual effect, reducing the total solar radiation for photosynthesis but also increasing the scattered light that plants use more efficiently.

The review highlights that agricultural production is affected by various climate change mechanisms, including rising temperatures, elevated atmospheric CO2 levels, changes in water resources, and other factors such as humidity and extreme events. Increased temperatures shorten the growing season of crops and can reduce yields, although in some higher latitudes, moderate warming may bring more favorable temperatures. Increased atmospheric CO2 concentrations can have a stimulating effect on crop growth by increasing photosynthesis, known as CO2 fertilization effectChanges in water resources, such as droughts and floods, have a negative impact on crop yields. Tropospheric ozone (O3) reduces crop yields and quality by damaging plant tissues. O3 pollution is estimated to have caused 33% of wheat, 23% of rice, and 9% of corn crop losses in China. Aerosols can have complex effects on crop growth through scattering of sunlight. Other pollutants, such as nitrogen oxides (NOx) and sulfur dioxide (SO2), also affect crop yields by directly damaging them and indirectly contributing to ozone and aerosol formation.

The document details that The agri-food system is a significant source of greenhouse gas (GHG) emissions, estimated to represent approximately one third of global GHG emissions. The main sources of these emissions include livestock farming (methane), fertilizer application (nitrous oxide), rice cultivation (methane) and land-use change (carbon dioxide). GHG emissions occur at all stages of the food system, from production and processing to transport, distribution and consumption. In addition The food system contributes significantly to air pollution, accounting for 10%–90% of pollutant emissions depending on the specific substance. For example, in 2018, it was responsible for more than half of the world's total nitrogen emissions (mostly in the form of ammonia (NH3)) and up to 35% of particulate matter emissions, leading to an estimated 22.4% of air pollution-related deaths.

The review analyzes various methodologies for assessing emissions from food systems, including life cycle assessment (LCA), multi-regional input-output analysis (MRIO) and physical trade flow analysis (PTF). Each method offers different perspectives on emissions across the food supply chain.

The document emphasizes that GHG emissions from agri-food systems contribute significantly to global warming. It is estimated that warming caused by emissions from agriculture and land-use change reached 0.55°C between 1855 and 2022. In addition to CO2, the agri-food system emits significant amounts of methane (CH4) and nitrous oxide (N2O), which have a stronger but shorter-lived warming effect compared to CO2. In addition, The food system has a profound impact on air quality, mainly through ammonia (NH3) emissions, which contribute to the formation of secondary particulate matter PM2.5. In 2018, air pollution from food system emissions was responsible for approximately 22.4% of global mortality due to poor air quality.

The document extensively adopts strategies to mitigate emissions from food systems on both the supply and demand sides. Supply-side measures include improved nutrient management in crops (optimization of fertilizer dosage and timing), adjustments in rice cultivation (for example, intermittent flooding of fields), alleviation of enteric fermentation in livestock (diet modification, feed additives), efficient manure management (optimization of storage and processing), carbon sequestration in soil (improved soil management practices) and biochar applicationOn the demand side, emphasis is placed on supporting the transition to more sustainable eating habits (more plant-based foods) and reducing food waste.

In the area adaptation of food systems to climate change and air pollution The document discusses strategies for crop production (development of more resistant varieties, adjustment of sowing dates, crop diversification) and animal production (improved breeding practices, selection of more resistant breeds). The concept climate-smart agriculture is presented as a holistic approach integrating crop production, livestock production, fisheries and agroforestry to achieve food security, climate change mitigation and adaptation.

At the end of the document highlights key directions for future research. These include comparing different impact assessment methodologies, examining extreme events and combined effects, focusing not only on yields but also on nutritional composition and pests, comprehensive monitoring of emissions throughout the supply chain, attention to non-CO2 emissions from agriculture, and the development of high-resolution inventories of pollutant emissions. The document also highlights the need for rapid and coordinated action by governments and relevant agencies to create a more sustainable and resilient food system, including comprehensive policies integrating mitigation and adaptation, international cooperation and taking into account food security in low- and middle-income countries. Integrating agricultural policies with broader environmental objectives is key to ensuring food security and strengthening global efforts to mitigate climate change and improve environmental health. Spring

The study is published in the journal Engineering .

Glossary of key terms

• Agri-food system: A complex network of activities associated with the production, processing, distribution and consumption of food, including agriculture, forestry, fishing and related industries.
• Greenhouse gas emissions (GHG): Gases in the atmosphere that absorb and emit infrared radiation, thereby contributing to the greenhouse effect and global warming (e.g. carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O)).
• Enteric fermentation: A digestive process in ruminants in which microorganisms in the digestive tract produce methane, which is subsequently released into the atmosphere.
• Land Use and Land Use Change (LULUC): Changes in land use (e.g. conversion of forest to cropland) that can lead to the release or sequestration of greenhouse gases.
• Ozone (O3): A gas that can be a pollutant harmful to vegetation and human health in the ground layer of the atmosphere and protects against harmful UV radiation in higher layers.
• Nitrogen oxides (NOx): A group of reactive gases containing nitrogen and oxygen that contribute to the formation of smog, acid rain, and affect vegetation.
• Sulfur dioxide (SO2): A pollutant that contributes to the formation of acid rain and fine particles and can damage vegetation.
• Fine particles (PM2.5): Tiny solid particles and droplets with a diameter of less than 2.5 micrometers that can penetrate deep into the lungs and pose health risks.
• Global Warming Potential (GWP): A relative measure of how much heat a given mass of a greenhouse gas traps in the atmosphere compared to the same mass of carbon dioxide over a given period of time (e.g. GWP100).
• Climate-smart agriculture: An approach to agriculture that seeks to sustainably increase productivity, improve resilience to climate change (adaptation) and reduce greenhouse gas emissions (mitigation).
• Carbon sequestration: The process of removing carbon dioxide from the atmosphere and storing it in long-term reservoirs such as soil or biomass.
• Biochar: A carbon-rich material produced by pyrolysis of biomass in low oxygen conditions that can be used as a soil amendment to improve soil properties and sequester carbon.
• Food Loss and Waste (FLW): Food that is lost along the supply chain or thrown away by consumers.
• Production-based emissions accounting: A method of attributing greenhouse gas emissions to the country or region where the production of goods and services physically takes place.
• Consumption-based emissions accounting: A method of attributing greenhouse gas emissions to the final consumer of goods and services, regardless of where they are produced.