Tuesday, 29 September 2015

Climate Change and Agriculture

Agriculture is a crucial socio-economic sector. In many developing countries, it accounts for a significant portion of the gross domestic product (GDP) and employs a large part of the population. Agriculture is central to food security, makes a major contribution to livelihoods and employment and is a driver of economic growth. Climate change is likely to have a strong impact on agriculture and poses a threat to food security.
Agriculture also generates a substantial share of the total GHG emissions in many developing countries. Actions to reduce net GHG emissions in the AFOLU sector provide valuable opportunities to build on and increase synergies with activities related to sustainable intensification, improved farm efficiency, climate change adaptation, food security and rural development. The NAMA framework is one of the possibilities that exists to unite actions to reach these goals into one coherent package.

NAMAs provide an opportunity for countries to maintain and enhance agricultural productivity while reducing GHG emissions.

NAMA is a relatively new concept in the agriculture sectors. For this reason, substantial awareness raising and readiness building is needed. The objective of this learning tool is to guide national policy makers, advisers, researchers, private sector and other stakeholders in developing countries to identify, design and implement NAMAs.

1.1. Food security and climate change

The world’s agricultural sectors face many challenges in meeting global food requirements .

Climate change affects the four dimensions of food security:
• food availability,
• food accessibility,
• the stability of food supply, and
• the ability of consumers to adequately utilize food including food safety and nutrition. Smallholder farmers, forest dwellers, herders and fishers will be the most affected by climate change because of their limited capacity to adapt to its impacts.

805 million people are chronically undernourished – about one in nine of the world’s population (FAO et al., 2014).

1.1.1. Examples of climate change impacts on agriculture

Crops and livestock production are affected by:
• increasing temperatures,
• changing precipitation patterns and
• more frequent and intense extreme weather events.

Fisheries production systems are affected by:
• increasing water temperatures,
• decreasing pH and
• changes in current sea productivity patterns.

Examples of climate change impacts and consequences on agriculture include:
• yield reductions, animals and crops shifting to new areas, declines in agro-biodiversity and ecological services;
• loss of agricultural incomes;
• humanitarian aid dependency; and
• increases in food prices, trading costs and other costs.

1.2. Rationale for future actions: avoid global warming

Growing population and changes in food consumption patterns (e.g. higher demand for milk and meat) will lead to increased GHG emissions from agriculture.

At the same time, to avoid the most serious impacts of climate change, major GHG emission cuts are required to hold the increase in global average temperature below 2 degrees Celsius above pre-industrial levels.

Food production will need to increase by 50–70 percent by 2050 to meet the needs of the expanding global population.

The reduction of GHG emissions:
• limits the impacts of climate change by addressing the its root causes; and
• reduces the extent and cost of adaptation to climate change.

1.3. Main sources of GHG emissions in agriculture and land use

There are a number of sources of GHG emissions in agricultural ecosystems. The main sources include:

Carbon dioxide (CO2)
• microbial decomposition of soil organic matter (SOM) and dead organic matter (i.e. dead wood and litter)
• deforestation
• burning of organic matter

Methane (CH4)
• enteric fermentation from livestock
• methanogenesis under anaerobic conditions in soils (e.g. during rice cultivation) and manure storage
• burning of organic matter

Nitrous oxide (N2O)
• nitrification and denitrification due to application of synthetic fertilizers and organic amendments (e.g. manure) to soils
• burning of organic matter (IPCC, 2006).

Along with CO2, N2O, CH4 emissions, burning of organic matter generates emissions of GHG precursors, such as:
• oxides of nitrogen (NOx),
• non-methane volatile organic compounds (NMVOC) and
• carbon monoxide (CO). Volatilization losses of ammonia and NOx from manure management systems and soils leads to indirect GHG emissions. Harvested wood products (HWP) also contribute to CO2 emissions and removals.

1.4. Direct GHG emissions from AFOLU

Distribution of GHG emissions by economic sector:
Energy              35%
AFOLU            24%
Industry            21%
Transport          14%
Buildings            6%

Data source: IPCC, 2014a.

GHG emissions from the AFOLU sector account for 24 percent of the total emissions (IPCC, 2014a).
The AFOLU sector is the largest emitting sector after the energy sector.

1.5. Global GHG emissions from agriculture by source

Agriculture alone contributes 10–12 percent of global GHG emissions (IPCC, 2014a).

Below is breakdown of agriculture emissions globally by sector:

Enteric fermentation               40%
Manure left on pasture           16%
Synthetic fertilizers                13%
Paddy rice                              10%
Manure management               7%
Burning of savannahs               5%

Source: FAOSTAT, 2014.

1.6. Increasing GHG emissions from agriculture

Over the last few decades, there has been a significant increase in global GHG emissions from agriculture, while emissions from deforestation are decreasing (IPCC, 2014a).

Global emissions from agriculture (crops & livestock) continued to increase by almost 100% in the last 50 years

1961       2.7 billion tonnes CO2 eq

2012       5.4 billion tonnes CO2 eq

Source: FAOSTAT, 2014.

               Examples of increases in emissions from 1961 to 2010
Source                                                                                           Percent (%)
Synthetic fertilizers                                                                            900
Manure (either organic fertilizer on cropland or
manure deposited on pasture)                                                              73
Enteric fermentation                                                                            50
Paddy rice cultivation                                                                          41

Source: Tubiello et al., 2013; FAOSTAT, 2014.

1.7. Net GHG emissions from agriculture by continent

Based on estimates, Asia contributes the highest proportion of GHG emissions from agriculture.
However, some countries that are large emitters can have relatively low per capita emissions, whereas others can have high per capita emissions but contribute a relatively small share of global emissions

By Average 1990–2010
Asia           42.6%
Americas   25.3%
Europe       14.1%
Africa        13.9%
Oceania       4.2%

By continent in 2012
Asia                        2,459 million tonnes CO2 eq
Latin America
and the Carribean      903 million tonnes CO2 eq
Africa                        798 million tonnes CO2 eq

Source: FAOSTAT, 2014.

1.8. Regional GHG data comparisons

The distribution of emissions from important categories varies between regions.
• Similarly, depending on the country key emitting agricultural subsectors vary by region.
• National estimates produced by FAO for agriculture and land are available in FAOSTAT.

Source: Graph modified after IPCC, 2014a, data source FAOSTAT.

1.9. Role of agriculture practices in GHG reduction and other benefits

The economic mitigation potential of agriculture is high
• 3 to 7.2 gigatonnes of CO2eq per year in 2030 at 20 and 100 USD per tonne of CO2eq.
• 70 percent of economic mitigation potential is in developing countries (IPCC, 2014a).

A number of agricultural practices can not only reduce and remove GHG emissions, but can also deliver many other important benefits, such as:
• supporting climate change adaptation;
• addressing agriculture as a driver of deforestation and other land use changes;
• reducing agriculture’s contribution to non-point pollution of water sources;
• increasing the potential for scaling up climate-smart agriculture (CSA) practices;
• promoting access to energy in rural areas; and
• fostering food security.

With appropriate mitigation actions it is possible to not only reduce GHG emissions but also to strengthen food security and rural livelihoods.

1.10. Mitigation and adaptation synergies

There are many activities that deliver both climate change mitigation and adaptation benefits. For instance:

Practices that increase SOM enhance soil carbon sequestration and improve nutrient supply and soil water-holding capacity, which strengthens the resilience of agricultural systems and increases productivity.

Agroforestry in silvopastoral systems can raise livestock productivity by reducing heat stress for animals. In addition, trees increase carbon storage in soils and biomass.

Watershed rehabilitation increases carbon stored in forests and rehabilitated land, reduces flood recurrence and improves resilience to natural disasters.

Improved institutions for land tenure can support soil conservation by providing incentives for long-term soil fertility improvement and nutrient-cycling measures.

addresses the root causes of climate change by decreasing GHG emissions and increasing carbon sinks

enables agricultural systems to be more resilient to the consequences of climate change

…both can and should be implemented together

1.11. Mitigation as a part of climate-smart agriculture (CSA)

Climate change mitigation is also one of the essential pillars of CSA.

CSA is an integrative approach to address the interlinked challenges of food security and climate change. It explicitly aims to:
• sustainably improve agricultural productivity, increase farm incomes, strengthen food security and promote development in an equitable manner;
• adapt and build the resilience of agricultural and food security systems to climate change at multiple levels; and
• reduce and/or remove GHG emissions from agriculture whenever possible.

To learn more about CSA, click here, or consult the Climate-Smart Agriculture Sourcebook by FAO, 2013.

1.11.1. Example: No-tillage farming – a climate-smart practice

No-tillage farming, in which ploughing is replaced by direct seeding under the mulch layer of the previous season’s crop

Resilience benefit
Significant financial benefits as farmers can save between 30–40 percent of time, labour and fossil fuel inputs

Adaptation benefit
Minimizes soil disturbance, provides permanent organic soil cover and diversifies crop species, which are grown in sequence and/or association

Mitigation benefit
Reduction of GHG emissions from soil disturbance and from fossil-fuel use of farm machinery

Source: Cited in UNEP, 2013.

1.12. Supply‐side and demand‐side mitigation options

Opportunities to reduce GHG can be divided in two groups: supply-side and demand-side options.

Supply side options include:
• reducing emissions from land‐use change, land management and livestock management;
• increasing terrestrial carbon stocks by sequestering and storing carbon in soils, biomass and wood products;
• reducing emissions from energy production through the substitution of fossil fuels with biomass; and
• increasing production without a commensurate increase in emissions reduces emission intensity (i.e. the GHG emissions per unit of product).

Demand side options include:
• cutting GHG emissions by reducing losses and waste of food and recycling wood;
• changing diets; and
• modifying wood consumption.

Demand‐side options are difficult to implement as they call for changes in consumption patterns.

A combination of supply-side and demand-side options can reduce up to 80 percent of the emissions from the AFOLU sector by 2030 (IPCC, 2014a).

1.13. Cropland cultivation and livestock management practices with potential to reduce net GHG emissions

GHG reductions and removals can be achieved through a variety of cost-effective agricultural practices (IPCC, 2007; UNEP, 2012). These actions can be divided into four main groups.

Group                                                                                           Examples
Increasing carbon stock                                        
agroforestry practices
improved crop varieties, which require less land for cultivation and at the same time produce higher yield and larger quantities of plant residues for carbon sequestration
restoration of cultivated organic soils
improved cropland management, including agronomy, nutrient management, tillage and residue management
improved water management, including irrigation and drainage
improved post-harvest practices and irrigation

Decreasing carbon loss
restoration of cultivated organic soils
prevention of deforestation
improved agronomic practices
tillage and residue management
zero burning
restoration of degraded lands (e.g. using erosion control, organic amendments and nutrient amendments)

Reducing non-CO2 emission
change of fertilizer type
improved rice cultivation practices
improved livestock management practices (e.g. improved feeding practices, breeding and other structural changes , or if meat-producing animals reach slaughter weight at a younger age, lifetime methane emissions can be reduced)
improved manure management (e.g. improved storage and handling and anaerobic digestion)
zero burning
restoration of cultivated organic soils

Increasing production efficiency
improved post-harvest practices and irrigation
improved crop varieties and livestock management
reduced food losses and waste

To learn more about mitigation practices, consult: Technologies for Climate Change Mitigation: Agriculture Sector, 2012, UNEP-DTU.

1.13.1. Example: Alternate wetting and drying (AWD) for rice cultivation

• Rice cultivation contributes more than 10 percent of global anthropogenic GHG emissions (FAOSTAT, 2014).
• AWD is a cropping practice that not only reduces methane emissions but also improves the management of water and nutrients in rice cultivation.
• In AWD, the rice fields are intermittently left dry instead of being kept continuously flooded.
• Through AWD, farmers can achieve 5–30 percent water savings, lower labour costs and increase profits with no significant loss in yield. In Bangladesh, yields have risen by more than 10 percent, raising incomes by USD 67–97 per hectare. In Rwanda and Senegal, rice yields increased from 2–3 tonnes per hectare to 6–8 tonnes due to the adoption of a system of rice intensification similar to AWD.
• Compared to continuously flooded rice production, AWD can reduce annual methane emissions by 40 percent on China’s rice paddies.

Source: Cited in UNEP, 2013.

MODULE 1: Climate change and agriculture

1.13.2. Example: Large-scale application of balanced feeding of livestock in India to reduce enteric methane and increase farmers’ income

Enteric fermentation from livestock contributes 32─40 percent of total agricultural GHG emissions (IPCC 2014a). Indian livestock production contributes approximately 13 percent of the global methane emissions from enteric fermentation. On most smallholder farms in India, the animal feed does not provide the proper balance of protein, energy and minerals. The objective of the ‘Ration Balancing Programme’ was to increase livestock productivity by giving the animals more balanced diets (FAO, 2012). Approximately 11 500 animals in seven locations in India were monitored during the programme.
Special software developed by the Programme allowed for the preparation of a balanced feed ration using local resources. This provided an optimum supply of nutrients and delivered several benefits.

Environmental benefits:
• a 15–20 percent decrease in methane emissions per kg of milk produced; and
• reduced nitrogen excretion into the environment.

Health benefits:
• improved animal immunity due to a reduction in the parasitic load.

Improved livelihood benefits:
• significant decrease in average cost of feeding;
• increased average milk yield, milk protein output and fat content;
• improved growth rate of calves, leading to early maturity and
earlier calving; and
• 10-15 percent increase in the net daily income per animal for farmers.

Because of the benefits achieved by the Ration Balancing Programme, it is a good candidate for large-scale implementation through a NAMA.

To learn more about the ‘Ration Balancing Programme’, consult: FAO, 2012.

1.13.3. Example: Biogas production from manure

In developing countries, small‐scale decentralized biogas digesters have the potential to meet the electricity needs of rural communities and promote rural development.
Biogas is more beneficial when it is deployed not as an additional land‐use activity spread over the landscape, but is integrated into existing land uses and influences the way farmers and forest owners use their land.
Methane digesters are particularly appealing because they:
• add revenue;
• cut waste management costs;
• provide cost-efficient electricity;
• reduce deforestation;
• reduce manure odour by as much as 95 percent;
• reduce pesticide costs;
• reduce surface and groundwater contamination and prevent infectious diseases;
• help minimize run-off and other water quality issues;
• capture methane, sulphur compounds and other gases, which would otherwise be released into the atmosphere;
• create nutrient-rich fertilizer, compost, livestock feed additives, and cow bedding from by-products; and
• partially free women from housework.

The negative side effects include methane releases through leakages and intentional venting.

Schematic representation of biogas productionThe negative side effects include methane releases through leakages and intentional venting.

Image source: Modified after www.seco.cpa.state.tx.us

1.13.4. Example: Livestock diet intensification through agroforestry

Higher quality diets for ruminants reduce the methane output per unit of milk and meat and increase meat and milk productivity.
Livestock production can be intensified through agroforestry by feeding animals the leaves of trees such as Leucaena leucocephala, which is widely grown in the tropics.

Adding even a small amount of Leucaena leaves to dairy cattle can:
•treble daily milk yield;
•quadruple daily weight gain;
•increase farm income considerably;
•reduce the amount of methane produced per kg of meat and milk by factors of 2 and 4, respectively; and
•increase carbon sequestration.
Widespread adoption of this option has substantial mitigation potential, because intensified diets would considerably reduce the number of ruminants needed to satisfy future demand for milk and meat.
Source: Campbell et al., 2014.

Agroforestry includes different management practices that deliberately incorporate woody perennials on farms and in the landscape. This increases the uptake and storage of carbon dioxide from the atmosphere in biomass and soils.

1.13.5. Example: Agroforestry for reducing deforestation

The United Republic of Tanzania is among the leading countries in Africa to embrace the Participatory Forest Management (PFM). By 2008, 4.1 million ha of the country’s forests were under PFM with 2 328 villages participating in the management of their forests. By combating deforestation and forest degradation, PFM in the United Republic of Tanzania has contributed to the reduction of GHG emissions.

PFM interventions have advocated for the sustainable use of forests with a clear focus on ensuring increased carbon stocks and augmenting forest ecosystem services. Some of the adaptation and mitigation activities have included:
• encouraging agroforestry;
• establishing community-based income generating activities;
• promoting ecotourism; and
• increasing the use of non-timber forest products. Though PFM lacks a well elaborated MRV system to gauge its contribution towards reducing GHG emissions, the practices in place have ensured protection of the forest resources even in areas that were previously subjected to intensive exploitation.

Source: Cited in Majule et al., 2014.

1.13.6. Example: Improved cooking stoves

Ethiopia’s Climate Resilient Green Economy Strategy notes that replacing open fires and rudimentary cooking stoves with more efficient stoves that need only half as much fuelwood or stoves that use other fuels has the potential to bring about an estimated 20 percent annual reduction in the country’s total GHG emissions (about 50 Mt CO2eq) by 2030.

The government has prioritised plans to deploy 9 million more efficient stoves by 2015. Using better stoves would not only save energy and reduce emissions, it would also:
• save USD 270 million in opportunity costs for fuelwood;
• increase rural household income by 10 percent;
• create many more jobs in making stoves;
• reduce severe health risks from smoke inhalation, and
• decrease hours spent gathering fuelwood, which is traditionally done by women and children, often in risky areas. The government has therefore developed an investment plan to support the scaling up of these activities. The plan includes programmes to improve production, distribution and financing, ideally through access to carbon credits.

For further details, consult: Federal Democratic Republic of Ethiopia, 2012.

1.14. Mitigation options for aquaculture and fisheries

Examples of actions through which GHG can be reduced:
• In the fisheries sector, the primary source of GHG emissions is fuel usage during fishing.
• In the aquaculture sector, the primary sources are feed production and excavation of mangrove forests. For both sectors energy saving and developing regional trade is important for reducing GHG emissions .

Additional options for reducing GHG emissions include:

• improving energy efficiency (e.g. improved fishing vessel design and operation);
• aquatic biofuel production and use;
• reducing overfishing and excess capacity;
• implementing fishing activities that are linked with improved fisheries management and healthy stocks; and
• installing and maintaining low-cost inshore fish aggregating devices in fisheries.

• improving feeding and reducing losses from disease in aquaculture;
• improving energy efficiency (e.g. improved aeration pumping systems);
• increased production efficiency;
• enhancing sequestration by expanding the planted areas of mangroves and floodplain forests;
• developing integrated multi-trophic aquaculture; and
• culturing low-trophic-level species.

At its current annual growth rate, aquaculture is expected to account for early 6 percent of anthropogenic N2O and other nitrogen emissions by 2030 (Hu et al. 2012).

For references and further information, consult: Climate-Smart Agriculture Sourcebook, FAO and Guidelines for Integrating Climate Change Adaptation into Fisheries and Aquaculture Projects, IFAD.

1.14.1. Example: Culture of low-trophic-level species

Cultured Indian major carp, Chinese carp, tilapia and sea cucumber (scavenger echinoderms feeding on debris) do not require fish oil and use small amounts of fish meal as feed and have a low carbon footprint.
For example, only 1.67 kilograms of CO2 are released per kilogram of tilapia compared to shrimp farming which releases 11.10 kilograms of CO2 per kilogram of shrimp.

Cultured molluscs and bivalves, such as clams, mussels and oysters, can remove substantial amounts of carbon from coastal oceans and also do not need fish oil or fish meal.
• Mussels could assimilate and remove up to 80 metric tonnes of carbon per hectare per year.
• The carbon footprint for mussels and oysters is 0.01 kilogram of CO2 per kilogram of production.

Source: IFAD, 2014, Guidelines for Integrating Climate Change Adaptation into Fisheries and Aquaculture Projects.

1.14.2. Example: Fuel savings for small fishing vessels

Saving fuel is important for reducing GHG emissions. The potential for savings is greatest when planning a new boat. For example, the engine can be matched to  the size and weight of the boat and the hull can be designed to give minimum resistance. Additionally, fuel usage can be reduced by:
• reducing speed;
• carrying out multiday fishing and mothership operations;
• servicing the engine and giving it air;
• using inboard instead of outboard engines;
• deploying sails;
• selecting the right size propeller; and
• keeping the bottom of the boat clean.

Hull fouling with slime, weeds and barnacles will slow down a boat. In the tropics, the increase in fuel consumption due to hull fouling can be 7 percent after only one month and 44 percent after half a year if antifouling paint is not used.
Fuel savings

Source: Gulbransen, 2012.
For guidance, consult the FAO publication Fuel savings for small fishing vessels, by Gulbransen, 2012.

MODULE 1: Climate change and agriculture

1.15. Complete life-cycle approach for GHG reduction

Apart from implementing GHG reduction strategies directly at the field level, it is also important to reduce net GHG emissions through all the stages of a product's life, including post-harvest storage, transportation, processing, retailing, consumption and disposal.

•product transport
•suppliers transport
•international freight

•factory energy

Retailing, consumption and disposal
•packaging and retail distribution
•delivery and customer transport
•waste disposal

1.15.1 Example: Life-cycle analyses of pig production in East and Southeast Asia

Over the past three decades, pig production has increased fourfold in East and Southeast Asia and is expected to further expand and intensify.

The main sources of emissions in pig production systems are:
• feed production, which alone represents about 60 percent of total emissions from commercial systems;
• manure, which accounts for 14 percent of total methane emissions in industrial systems; and
• on-farm energy use and post-farm activities (6 percent).

The following mitigation options were explored using the FAO Global Livestock Environmental Assessment Model (GLEAM):
• improved manure management (through increased use of anaerobic digestion);
• adoption of more energy efficient technologies and low-carbon energy; and
• improved feed quality, animal health and animal husbandry in intermediate systems.

The results of GLEAM modelling demonstrated that with feasible improvements in manure management, feed quality, animal health and animal husbandry, and the adoption of more efficient technologies and low-carbon energy, emissions in commercial pig production could be reduced by 20 to 28 percent from baseline emissions with stable production.
Results also demonstrated that the interventions could lead to a 7 percent increase in pig meat production. In this scenario, the technical mitigation potential would reach 14 to 23 percent (Gerber et al., 2013).

For further details read the FAO report Tackling climate change through livestock – A global assessment of emissions and mitigation opportunities, by Gerber et al., 2013

Source: FAO, 2015.

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