Abstract
Food production is an important source of anthropogenic greenhouse gas (GHG) emissions. Quantifying the carbon footprint of all the major food categories in different continents is critical for accurately evaluating various aspects of GHG emissions from food production on a continental and global scale. Such information, however, is lacking. Thus, we conducted a meta-analysis of plant-based and animal-based food production in all continents comprehensively using 5353 carbon footprint values from 524 published papers and calculated GHG emissions from food production (system boundary is from cradle to farm gate) at the continental and global scale. Our results indicate that the average carbon footprint of plant-based foods amounts to 0.66 kg CO2-eq kg-1, which is only 10.7% of animal-based foods (6.15 kg CO2-eq kg 1). The carbon footprint of plant-based food in Asia and Europe is 8.9%–184% higher than that of other continents. Africa has the lowest carbon footprint for plant-based foods, owing to its low agricultural input and limited crop management. However, the carbon footprint of animal-based foods in Africa and Asia is 2.5%-150% higher than that of other continents, with North America and Oceania recording the lowest. Total annual GHG emission from global food production reached 8125 Mt CO2-eq, with grains, meat, and milk together accounting for 70.8%. Asia, owing to its large production, emerged as the largest emitter, accounting for 55.4% of global GHG emissions. It was followed by Europe (16.3%) and North America (10.5%), while Africa, South America and Oceania together emit 17.8%. In summary, our study presents the most comprehensive account of the carbon footprint of food production at the continental and global scale to-date, which will help develop strategies and policies to reduce GHG emissions at various levels such as geographical regions, food and nutrition security, resource availability and resource use.
Generated Summary
This study presents a meta-analysis to comprehensively analyze the carbon footprint (CF) of food production across different continents. The research involved analyzing 5353 carbon footprint values from 524 published papers to calculate greenhouse gas (GHG) emissions from food production, spanning from the cradle to the farm gate. The study aimed to compare plant-based and animal-based food production across various continents, identifying key drivers of inter-continental variations in CF. The study provides a comprehensive account of food production’s carbon footprint at both continental and global scales, which can help develop strategies and policies to reduce GHG emissions in different regions.
Key Findings & Statistics
- The average CF of plant-based foods was 0.66 kg CO2-eq kg-1, while animal-based foods had a significantly higher average CF of 6.15 kg CO2-eq kg-1.
- The CF of plant-based foods in Asia and Europe were 8.9%–184% higher than in other continents.
- Africa had the lowest CF for plant-based foods.
- The CF of animal-based foods in Africa and Asia was 2.5%-150% higher than other continents, with North America and Oceania recording the lowest.
- Total annual GHG emissions from global food production reached 8125 Mt CO2-eq.
- Grains, meat, and milk together accounted for 70.8% of these emissions.
- Asia was the largest emitter, accounting for 55.4% of global GHG emissions, followed by Europe (16.3%) and North America (10.5%).
- Africa, South America, and Oceania together emitted 17.8%.
- The highest CF among plant-based foods was rice (1.31 kg CO2-eq kg-1), while wheat, maize and other grains were lower.
- The CF of roots, sugar, pulses, nuts, vegetable oils, vegetables, and fruits were 0.28, 0.45, 0.40, 0.98, 0.79, 0.57, and 0.39 kg CO2-eq kg-1, respectively.
- Beef and lamb had the highest CF among animal-based foods, at 15.0 and 13.8 kg CO2-eq kg-1 LW, respectively.
- Pork and poultry were 3.75, 3.10 and 2.24 kg CO2-eq kg-1 LW, respectively.
- Egg and milk had the lowest CF, at 2.10 and 1.64 kg CO2-eq kg-1, respectively.
- Asia had the highest CF for wheat (0.68 kg CO2-eq kg-1) and maize (0.55 kg CO2-eq kg-1).
- Europe recorded the highest CF for rice at 2.37 kg CO2-eq kg-1.
- Europe recorded the highest CF for sugar, pulses, and vegetables.
- Africa recorded the highest CF for vegetable oils at 1.69 kg CO2-eq kg-1.
- The CF of beef, lamb, poultry meat, and milk in Africa were the highest.
- The total global GHG emission from all food production was 8125 Mt CO2-eq per year.
- Plant-based foods accounted for 42.3% (3433 Mt CO2-eq).
- Meat, grains, and milk were the main contributors to GHG emissions, accounting for 27.1%, 24.9%, and 18.8%, respectively.
- Asia recorded the highest GHG emissions from food production (4502 Mt CO2-eq), followed by Europe (1322 Mt CO2-eq).
- Using a global average CF led to underestimation of GHG emissions in Asia by 6.3% and in Africa by 16%.
- Meat, grains and milk were the main contributors to GHG emissions for all continents and they accounted for 67.2%, 75.6%, 80.3%, 77.8%, 64.2% and 86.4% of GHG emissions in Asia, Europe, North America, South America, Africa and Oceania respectively.
- Asia recorded 55.4% (4502 Mt CO2-eq) of global GHG emissions from food production.
Other Important Findings
- The study highlights that the average CF of plant-based foods (0.66 kg CO2-eq kg−1) is significantly lower than that of animal-based foods (6.15 kg CO2-eq kg−1 LW).
- Rice has the highest CF among plant-based foods due to high CH4 emissions from rice fields.
- Ruminant meats (beef and mutton) have a higher CF than non-ruminant meats.
- Asia and Europe show the highest CF for plant-based foods, while Africa has the lowest, indicating variations due to agricultural practices.
- Africa and Asia have higher CF for animal-based foods compared to North America and Oceania.
- GHG emissions from global food production are primarily driven by meat, grains, and milk.
- The study underscores that using a global average CF can lead to significant uncertainties in GHG emission estimations at the continental level.
Limitations Noted in the Document
- The study acknowledges limitations due to the scarcity of region-specific and food-specific literature, particularly for Africa and Oceania.
- The absence of uniform standards for reporting variability in some studies from developing countries may introduce uncertainty in the aggregation of results.
Conclusion
The study’s findings emphasize the significant contribution of the global food system to GHG emissions, with plant-based foods having a lower CF compared to animal-based foods. The variations in CF across continents highlight the impact of agricultural practices, feed conversion efficiencies, and livestock management. The study’s findings emphasize the need for targeted strategies to reduce GHG emissions from food production. The findings highlight that GHG emissions from global food production are primarily driven by meat, grains, and milk. The research suggests that improving agricultural production efficiency, adopting best management practices, and transitioning to sustainable practices are crucial steps. The study’s results underscore the need for regional-specific CF assessments for accurate GHG emission evaluations and the development of effective mitigation strategies. The study emphasizes the need for continuous improvement in agricultural practices and technologies, while also highlighting that adopting practices like balanced fertilization, the use of new fertilizers, and optimized water management can help to reduce GHG emissions from food production. The study indicates that measures to reduce GHG emissions from food production include enhanced efficiency in agricultural practices, promoting sustainable agricultural production methods, and implementing appropriate restructuring of agricultural systems.