AGRICULTURE

CHAPTER 4 FOOD AND AGRICULTURE SYSTEMS IN CLIMATE CHANGE MITIGATION
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and provides fodder for livestock. The use of
nitrogen-fixing leguminous trees, such as
Faidherbia albida, improves soil fertility and
yields. Although there is clear and abundant
evidence of the positive impacts of agroforestry
practices on productivity, adaptive capacity and
carbon storage, a wide variety of systems and
tree species need to be considered in
different contexts. •
MITIGATION COSTS,
INCENTIVES AND
BARRIERS
There are many feasible and promising
approaches to climate change mitigation in the
AFOLU sector, and the technical potential is
considerable. But what are the costs and thus the
economic potential of mitigation? In other words,
what is the hypothetical price of carbon that
would induce farmers, fisherfolk and foresters to
apply appropriate practices for sequestering
carbon and reducing emissions?
Based on the combined mitigation potential of
forestry and agriculture, estimated in the IPCC’s
Fourth Assessment Report, the IPCC suggests an
economic potential in 2030 of between ≈3 and
≈7.2 Gt of carbon dioxide equivalent a year at
carbon prices of US$20 and US$100 per tonne,
respectively (Smith et al., 2014). 8 Among regions,
the largest mitigation potential for agriculture,
forestry and land use is found in Asia, at all
levels of carbon values (Figure 15, based on
Smith et al., 2014).
Forestry could make a significant contribution to
mitigation at all levels of carbon prices. At low
prices, the contribution of forestry is close to
50 percent of the total from the AFOLU sector; at
higher prices the share of forestry is lower.
8 A range of global estimates of sequestration potential at different levels
of costs has been published since the IPCC’s Fourth Assessment Report of
2007. The estimates differ widely. For carbon values up to US$20 a tonne,
they range from 0.12 to 3.03 GtCO 2 -eq per year. For values up US$100
per tonne, they range from 0.49 to 10.6 GtCO 2 -eq (Smith et al., 2014).
Forestry represents the bulk of mitigation
potential in Latin America, at all levels of carbon
prices. However, different forestry options have
different economic mitigation potentials in
different regions. Reduced deforestation
dominates the forestry mitigation potential in
Latin America and in the Middle East and Africa.
Forest management, followed by afforestation,
are the major options in OECD countries, Eastern
Europe and Asia.
Among other mitigation options, cropland
management has the highest potential at lower
carbon prices of US$20 per tonne. At US$100, the
restoration of organic soils has the greatest
potential. Also, the potential of grazing land
management and the restoration of degraded
lands increases at higher carbon prices (Smith et
al., 2014).
These estimates of economic mitigation potential
provide broad indications of how to target
interventions in the most cost-effective way.
However, more detailed assessments are needed
in order to properly assess AFOLU’s mitigation
potential, the impacts on vulnerable production
systems and groups, and the costs of
implementation. It is a pre-requisite that practices
optimized to reduce GHG emissions or sequester
carbon should also protect the land tenure rights
of small-scale producers and contribute to food
security and climate change adaptation,
particularly for the most vulnerable groups.
A range of institutional and economic
approaches can facilitate the implementation of
agricultural emission reductions. On the
institutional side, these would include providing
information to farmers about agricultural
practices that create adaptation/mitigation
synergies and, if needed, access to credit to
implement them. On the economic side, options
include positive incentives for farmers to provide
and maintain carbon sinks; taxation of nitrogen
fertilizer in countries where it is being
overutilized, a measure which is already applied
in some OECD countries to reduce nitrate
pollution; and supply-chain initiatives that
market food products with a low carbon
footprint (Paustian et al., 2016). •
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