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Climate change, poverty and hunger must be tackled together
The agriculture sectors accounts for at least one-fifth of total emissions of greenhouse gases. A new FAO report discusses the challenge of reducing our greenhouse gas emissions while at the same time meeting the world’s demand for food.
Emissions from agriculture mainly come from our livestock and crop production, and the conversion of forests to agricultural land. In 2050, the global demand for food is projected to be at least 60 per cent higher than 2006 levels. In the coming decades, population growth will mainly take place in those parts of the world with the highest prevalence of malnutrition and high vulnerability to the effects of climate change. The 2016 FAO report – The state of food and agriculture – highlights several key areas relevant to the combination of climate change, agriculture and food safety. It also describes how the agricultural sector can and should respond to climate change through both adaptation and mitigation. There are many synergies and trade-offs among the objectives of food security, adaption and mitigation, and we should therefore tackle all of them as one. To optimise the mitigation potential of agriculture, we must create an understanding of how carbon and nitrogen cycles interact with agricultural activities.
The Paris Agreement calls for measures to conserve and increase sinks and reservoirs of greenhouse gas, and one of these measures is to promote improved agricultural practices. Soil is the second most important carbon pool on earth, right after water, and small changes in the stock of carbon may result in large changes in the carbon dioxide in the atmosphere. The composition of soil can vary and it can behave differently depending on which part of the world it is found in. This means that to maximise carbon sequestration, different agricultural approaches are needed. But generally, the integration of trees and shrubs in the agricultural landscape prevents erosion and supports carbon sequestration, which also improves the resistance of soils to drought and flooding.
Agriculture is heavily dependent on nitrogen; together with water it is the most important element for successful harvests. Fifty per cent of the nitrogen in food production depends on fertilisers, while the other half is found in soil, animal manure, crop residues etc. Unfortunately, much of the nitrogen in the agricultural system is lost through volatilisation and leaching. Those losses are important to consider since nitrous oxide is the third most vital greenhouse gas. Nitrogen fertilisers also have a direct negative impact on climate change, because of the energy-demanding production process.
Six case studies show that sustainable practices in the livestock sector would lead to a reduction of between 14 and 41 per cent of the sector’s total emissions of greenhouse gases. For the reduction of methane emissions and for sequestering soil carbon in grazing lands, improved grazing management and sowing of legumes were the most affordable practices according to the studies. It was shown that these measures could reduce emissions by 11 per cent of annual global ruminant emissions. In fact, the potential of changes varies within similar livestock systems due to differences in agro-ecological conditions, farming practices and management of the supply chain. In the livestock sector, improving pasture productivity can limit the expansion of pasture into tropical forests and enhance the conservation and sustainable development of carbon-rich landscapes.
By increasing carbon sequestration and reducing emissions from the value chain, fisheries and aquaculture can also contribute to climate change mitigation. The sector can reduce its fuel and energy use through more efficient fishing techniques and by improvements along the entire supply chain. It is mainly the processing, storage and transportation of the fish that is the main source of the sector’s contribution to climate change.
Forests are calculated to bind 2.6 billion tons of carbon each year and deforestation currently accounts for about 11 per cent of all greenhouse gas emissions in the world. Planting new trees and reducing or avoiding logging are a few ways to reduce losses from forests. These goals can be achieved by improved education, involving rural communities in planning and decision-making, increasing the use of new conservation methods, etc.
To further reduce agriculture’s negative impact on climate change, our food system could be improved by minimising losses and waste, and by promoting sustainable diets. FAO estimates that 30–40 per cent of food produced for humans is lost before it even reaches the market, due to inadequate routines in agriculture and throughout the supply chain. By improving soil health, improving feed efficiency for livestock benefit, favouring pollinators and creating diversified landscapes this number can be reduced. In low-income countries, most of the food waste is seen at the beginning of the supply chain, while the waste in high-income countries is caused directly by consumer behaviour and policy regulations. A combination of less meat, low intake of seafood and variety and balance between different products seems to have a good influence on our health and contributes to reduced emissions.
The report shows estimates of the economic mitigation potential. Regarding all levels of carbon values, the largest mitigation potential for agriculture, forestry and land use is found in Asia. Among other mitigation options, cropland management has the highest potential at lower carbon prices of US$20 per tonne. At higher prices of US$100, the restoration of organic soils has the greatest potential. The potential of grazing land management and restoration of degraded soils increases with higher carbon prices. The FAO report estimate that forestry represents the highest mitigation potential in Latin America, at all levels of carbon prices. Forest management, followed by afforestation, are the major options in OECD countries, Eastern Europe and Asia.
There are several institutional and economic approaches that can facilitate the implementation of agricultural emission reductions. The institutional approach would include providing information to farmers about agricultural practices that create adaptation/mitigation synergies, as well as access to credit to implement such measures. The economic approach would include positive incentives for farmers to provide and maintain carbon sinks, the taxation of nitrogen fertiliser in countries where it is over-used, and supply-chain initiatives to market food products with a lower carbon footprint.
To reduce the negative trends in the agriculture sector, FAO suggest that we should reduce overgrazing, recycle crop residues as fertiliser, increase the use of cover crops, intercropping, and agroforestry. Further measures include the use of improved plant varieties, nitrogen-fixing legumes, organic fertilisers and improved water management.
Five strategies we need to adopt according to the FAO report: improved crop production, improved animal production, improved manure management, improved food utilisation and less protein in diets.
The state of food and agriculture. Climate change, agriculture and food security.
A report from FAO (Food and Agriculture Organization of the United Nations), 2016. http://www.fao.org/3/a-i6030e.pdf