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Management of energy in the context of CSA

概 念

Energy and food chains

Energy is needed at every stage of the food chains. The relationship between energy and food production have evolved and grown stronger over time. Fossil fuels have become a major input in modern agricultural production. However, agriculture and forestry have always been a traditional source of energy generated from biomass. The energy generated by agrifood chains can be partially used in food production. It can also by exported outside the agrifood chain, for example,  through the sale of biogas produced on farms to local households, or through the generation of electricity from agricultural residues that can be fed into the national energy grid.

Figure B9.1. Energy FOR and FROM Agrifood Chains 

These two-way linkages between energy and agriculture — the energy for and from agrifood chains —i, are illustrated in Figure B9.1.

Source: Authors

The FAO Energy-Smart Food for People and Climate Programme (FAO, 2011a; FAO, 2011b), estimates that the agrifood sector currently accounts for around 30 percent of the world’s total end-use energy consumptionii and much of this energy comes from fossil fuels. More than 70 percent of this energy is used beyond production (Figure B9.2). In countries with a high gross domestic product (GDP) most of this energy is used for processing and transport. In low-GDP countries, cooking consumes the highest share.

Figure B9.2. Indicative shares of final energy consumptioniii for the agrifood sector for high- and low-GDP countries

Source: FAO 2011a

The connections between energy and food chains have grown stronger as agriculture has become increasingly reliant on mineral fertilizers, irrigation and machinery. Post-production  activities, such as food storage, cooling, processing and distribution, are also energy-intensive. Prices for nitrogen fertilizers and other fossil fuel-dependent inputs are closely related to the price of crude oil. Consequently, the costs of energy have a direct impact on the production costs of the agricultural sectors and food prices, in particular in the case of medium to large farms. Over the last decades, the increased use of energy by the agrifood sector has significantly contributed to feeding the world. Energy from fossil fuels has expanded mechanization of the agricultural sectors, boosted fertilizer and feed production and improved food processing and transportation. Between 1900, when energy inputs were limited to low-level fertilization and rudimentary mechanization, and 2000, the world’s arable area doubled, and the energy content of edible crops expanded six-fold. This greater productivity was made possible by an 85-fold increase in energy input per hectare (Smil, 2008). This transformation occurred in an era when oil was inexpensive, and there was little concern about climate change. Times have changed. 

The high use of fossil fuels is a key contributor to climate change. As a result, agrifood chains that are highly dependent upon fossil fuels pose serious challenges to development. This dependancy could also hamper food security in the future. 

Business-as-usual development would lead to simultaneous increase in the needs for water, energy and food by more than 40 percent by 2030. This development scenario is clearly unsustainable. A sustainable approach must focus on the water-energy-food nexus, and address trade-offs and capitalize on synergies in the use of these resources (FAO, 2014). 

Food losses occur at all stages of the supply chain. About one-third of the food that is produced is lost or wasted (FAO, 2011c). The energy embedded in global annual food losses amounts to around 38 percent of the energy consumed by the whole food chain (FAO, 2011a; FAO, 2011b). 

One of the world's greatest challenges is to develop global food chains that emit fewer greenhouse gas emissions, have a secure supply of energy, are resilient to fluctuating energy prices, make efficient use of water, energy and land, and can continue to ensure food security and foster sustainable development. This calls for energy-smart food chains that:

  1. Ensure adequate access to modern energy services where needed in agri-food chains; and achieve this  through: 
  2. Better  energy efficiency, which would be measured in the amount of food produced (preferably calculated in nutritional units) per unit of energy consumed;
  3. Gradual introduction of renewable energy use diverse energy sources, with an emphasis on renewable energy, and integrate food production and the generation of renewable energy; 
  4. Sustainable bioenergy; and
  5. A water-energy-food nexus approach in work related to the above-mentioned objectives.

Bioenergy has a special role to play in safeguarding food security because it can be obtained from the same feedstocks as food. Although biomass is often used in unsustainable ways, it is found almost everywhere and is currently, and for the foreseeable future, the most important source of renewable energy. Biomass is the main source of energy for cooking in many developing countries and it is also used for heating. Agrifood chains not only use bioenergy, they can produce it. However, putting bioenergy to use in an appropriate manner is more complex than with other types of renewable energy. If it is not well managed, bioenergy development may jeopardize food security by increasing competition for resources. It could also harm the environment, if land is deforested to establish biofuel plantations or if forests become degraded through the unsustainable collection of wood for fuel. These issues are considered in Box B9.1.

Box B9.1 Can biofuels contribute to climate-smart agriculture? 

The International Energy Agency projects that the production of biofuels will provide 27 percent of global transport fuels by 2050 (IEA, 2011). Since 2010, policy support measures have played a critical role in the rapid increase in biofuel production, principally for transport. This support has been motivated by a desire to strengthen energy security, reduce greenhouse gas emissions, advance rural development and increase the incomes of agricultural producers. After the rapid introduction of new and expanded support measures, there is now a broader evidence base for reviewing the impacts of increased biofuel production and determining how policies might be adjusted to address changing goals and concerns.

Listed below are some possible contributions biofuels can make to climate-smart agriculture.

  • Biofuels in solid, liquid and gaseous forms can improve access to modern energy services for household uses and agricultural production. In this way, they can contribute to sustainable increases in productivity and income. A study on small-scale bioenergy initiatives (Practical Action Consulting, 2009) shows that improvements in bioenergy production can be achieved with minimum risks to sustainability.
  • Biofuels, especially when produced on a small scale, can strengthen adaptation to climate change by increasing local energy self-sufficiency. However, they may also bring about their own climate risks by changing the way land is used and increasing the competition between different uses of biomass (e.g. energy, soil management, animal feed) 
  • The impacts of bioenergy on greenhouse gas emissions and carbon sequestration are complex and the subject of much debate. Bioenergy is often considered to be carbon-neutral because the generation of biomass by photosynthesis absorbs the same amount of carbon dioxide that is released when the biomass is burned. However, this does not take into account the connections between the carbon cycle and other natural cycles, related to nitrogen, phosphorus and water. These elements are also required for photosynthesis and are consumed whenever biomass is produced. Soil nutrients are taken up by plants and need to be replenished. Replenishing these nutrients (e.g. through fertilizer applications) can produce greenhouse gas emissions, especially nitrous oxide. To understand how bioenergy development may affect emissions, a full life cycle assessment, which considers agricultural production and processing, and the direct and indirect changes in land use, must be carried out. 
  • Some good practices that can improve the performance of biofuels in terms of climate change mitigation include:
  1. agroecological zoning, which can ensure that biofuel development is avoided in high carbon areas (e.g. primary forests, peat land) and promoted in areas where the land is highly suitable;
  2. the use of crop residues for biofuel production, whenever this is compatible with their use for soil management (soil fertility improvement, mulching) and/ or as animal feed; and
  3. conservation agriculture, which is generally a low-carbon farming practice that can sometimes sequester carbon.

More broadly, biofuel policies and programmes should act in synergy with programmes related to agricultural development rather than with policies that artificially support biofuel demand. A sound and integrated approach to bioenergy development, particularly biofuel development, is required to reduce risks and harness opportunities. This approach requires:

  • an in-depth understanding of the situation, the related opportunities and risks, and synergies and trade-offs;
  • an enabling policy and institutional environment, with sound and flexible supportive policies (e.g. targets and incentives) and the means to implement them;
  • the implementation of good practices by investors and producers to reduce risks and increase opportunities, along with appropriate policy instruments to promote these good practices; 
  • proper impact monitoring and evaluation, and policy response mechanisms; and
  • capacity building and good governance in the implementation of the above.

To promote this sound and integrated approach, FAO has been developing a set of tools which are part of FAO’s Sustainable Bioenergy Toolkit: Making Bioenergy Work for Climate, Energy and Food Security (FAO, 2013).