PART 4

Climate change

Historically, farmers, pastoralists, forest dwellers andfishers have learned to cope with climate variability andhave often adapted crops and farming practices to suitnew conditions. But the severity and pace of climatechange is presenting new, unprecedented challenges.

The poorest and most food-insecure regions around theglobe are the most vulnerable to effects of climatechange. In Africa, low levels of food security and eco-nomic development conspire with high levels of climaterisk, while large populations and heavily exploited natu-ral resources and climate risk threaten South Asia’s poor.

Climate change will significantly impact agriculture byincreasing water demand, limiting crop productivity andreducing water availability in areas where irrigation ismost needed or has comparative advantage. Global at-mospheric temperature is predicted to rise by approxi-mately 4 oC by 2080, consistent with a doubling of at-mospheric CO2 concentration. Mean temperatures areexpected to rise at a faster rate in the upper latitudes,with slower rates in equatorial regions. Mean tempera-ture rise at altitude is expected to be higher than at sealevel, resulting in intensification of convective precipita-tion and acceleration of snowmelt and glacier retreat.

In response to global warming, the hydrological cycle isexpected to accelerate as rising temperatures increasethe rate of evaporation from land and sea. Thus rainfallis predicted to rise in the tropics and in higher latitudes,but decrease in the already dry semi-arid to arid mid-latitudes and in the interior of large continents. Water-scarce areas of the world will generally become drier andhotter. Both rainfall and temperatures are predicted tobecome more variable, with a consequent higher inci-dence of droughts and floods, sometimes in the sameplace.

The future availability of water to match crop water re-quirements is compounded in areas with lower rainfall,i.e. in those that are presently arid or semi-arid, in ad-dition to the southern, drier parts of Europe and NorthAmerica. Runoff (the water flow from soil when infil-trated to full capacity) and groundwater recharge areboth likely to decline dramatically in these areas.

Map 62:

−1.0

−0.5

0.0

0.5

1.0

1.5

2.0

Global surface temperature (°C, Temperature difference of 2000−08 versus 1940−80)

Source: IPCC

Metalink: P4.ENV.IPCC.CC.GSTG, p. 349

→ Global warming will have significant im-pacts on agriculture

→ Most notably, these include rising sur-face temperatures, increasing carbondioxide concentration and changingrainfall patterns

→ The extent of these changes will deter-mine the carrying capacity of bio sys-tems to produce enough food

300

CLIMATE CHANGE

−1.0

−0.5

0.0

0.5

1.0

1.5

2.0

Global surface temperature (°C, Temperature difference of 2000−08 versus 1940−80)

Chart 109: Rising surface temperature is symptomatic of climatic change

Global surface temperature (1850-2010)

◦ C

-0.4

-0.2

0.0

0.2

0.4

1850 1900 1950 2000

Source: IPCC

Metalink: P4.ENV.IPCC.CC.GST, p. 349

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Runoff is also expected to decline dramatically in areaswhere annual potential evapotranspiration exceeds rain-fall, such as in south eastern Australia where a 40 per-cent decrease is anticipated. Relatively small reductionsin rainfall will translate into much larger reductions inrunoff, for example, a 5 percent precipitation decrease inMorocco will result in a 25 percent reduction in runoff.

Although mean annual runoff may be less affected inglacier-fed river systems, the timing of flowswill change,which could have critical consequences for agriculture.Where rainfall volume increases and becomes more in-tense (Indian monsoon, humid tropics), a greater propor-tion of runoff will occur as flood flow that should be cap-tured in dams or groundwater to be useable.

About 40 percent of the world’s irrigation is supportedby flows originating in the Himalayas and other largemountain systems (e.g. Rocky Mountains in the west-ern United States of America and Tien Shan in CentralAsia). The loss of glaciers worldwide has been one ofthe strongest indicators of global warming. The impactson some river systems (such as the Indus) are likely tobe significant and will change the availability of surfacewater for storage and diversion as well as the amount ofgroundwater recharge.

As temperatures rise, the efficiency of photosynthesis in-creases to a maximum and then falls, while the rate ofrespiration continues to increase more or less up to thepoint that a plant dies. All else being equal, the produc-tivity of vegetation thus declines once temperature ex-ceeds an optimum. In general, plants are more sensitiveto heat stress at specific earlier growth stages (some-times over relatively short periods), than to seasonal av-erage temperatures.

Increased atmospheric temperature will extend thelength of the growing season in the northern temperatezones, but will reduce it almost everywhere else. Cou-pled with increased rates of evapotranspiration, waterproductivity and potential crop yields will fall. However,low yields and water productivity in many parts of thedeveloping world do not necessarily mean that they willdecline in the long term. Rather, farmers will have tomake agronomic improvements to increase productivityfrom current levels.

Map 63:

No Data < 400 400 − 1000 1000 − 1500 1500 − 2000 > 2000

Average precipitation in depth (mm per year, 2008)

Source: FAO, Land and Water Division (AQUASTAT)

Metalink: P4.ENV.FAO.ACQ.CLIM.APD, p. 344

→ Average precipitation is the long-termaverage in depth (over space and time)of annual rainfall in a country

→ Harvest outcomes in many countries aredependent on sufficient rainfall

→ Over 90 percent of agriculture in sub-Saharan Africa, for example, is managedunder rainfed systems

302

CLIMATE CHANGE

No Data < 400 400 − 1000 1000 − 1500 1500 − 2000 > 2000

Average precipitation in depth (mm per year, 2008)

Chart 110: Despite a large increase in average rainfall in 2010, Sahel precipitation rateshave been persistently below the long-term mean in recent decades

Sahel rainfall anomalies (1900-2010)

mmperyear

-3

-2

-1

0

1

2

3

1900 1920 1940 1960 1980 2000

Source: JISAO

Metalink: P4.ENV.JISAO.CLIM.SAHEL, p. 350

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Increased atmospheric concentrations of CO2 enhancephotosynthetic efficiency and reduce rates of respiration,offsetting the loss of production potential due to tem-perature rise. However, scientific evidence demonstratesthat all factors of production need to be optimal to real-ize the benefits of CO2 fertilisation.

Early hopes for substantial CO2 mitigation of productionlosses from global warming have not materialized. Also,by the time CO2 levels have doubled, temperatures willalso have risen by 4 oC, negating any benefit.

Agriculture will also be impacted by more active stormsystems, especially in the tropics, where cyclone activityis likely to intensify in conjunction with increasing oceantemperatures. The evidence of this is starting to emerge.

Sea level rise will affect drainage and water levels incoastal areas, particularly in low-lying deltas, and willresult in saline intrusion into coastal aquifers and riverestuaries.

In order to stabilize output and income, production sys-tems must become more resilient, i.e. more capable ofperforming well in the face of disruptive events. Moreproductive and resilient agriculture requires transfor-mations in the management of natural resources (e.g.land, water, soil nutrients, and genetic resources) andhigher efficiency in the use of these resources and in-puts for production. Transitioning to such systems couldalso generate significant mitigation benefits by increas-ing carbon sinks, as well as reducing emissions per unitof agricultural product.

Further reading

• FAO Climate Change (www.fao.org/climatechange/)• FAO Climate change, water and food security - FAO(www.fao.org/docrep/014/i2096e/i2096e00.htm)

• FAO Energy-smart food for people and climate (www.fao.org/docrep/014/i2454e/i2454e00.pdf)

• Intergovernmental Panel on Climate Change (IPCC)(www.ipcc.ch/)

Chart 111: In the past two decades CO2 concentrationhas risen by 10 percent. Land use and biomass burningaccount for over 9 percent of global CO2 emissions

CO2 concentration (1959-2010)

ppm

0

100

200

300

1960 1970 1980 1990 2000 2010

Source: IPCC

Metalink: P4.ENV.IPCC.CC.C02, p. 349

Chart 112: Agriculture in the United States emits farmore GHGs than any other country, and almost threetimes more than the next largest emitting country

Total Greenhouse Gas (GHG) emissions from agriculture (2008)

Million gigagrams CO2 equivalent

United States of America

Russian Federation

France

Australia

Germany

Canada

United Kingdom

Spain

Poland

Italy

0.0 0.1 0.2 0.3 0.4

Source: World Bank

Metalink: P4.ENV.FAO.BIO.GHG.AG, p. 344

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CLIMATE CHANGE

Chart 113: Global average yields for major food crops have risen

Long-term yields, global crops (1961-2009)

tonnesperha

2

3

4

5

1970 1980 1990 2000 2010

Maize Rice Wheat

Source: FAO, Statistics Division

Metalink: P3.FEED.FAO.ESS.WT.YLD, p. 278

Chart 114: ... but yield variability in all regions has increased in the past five decades

Long-term cereal yield variability (1961-2010)

%p.a.

1

2

3

4

1970 1980 1990 2000 2010

Developed East Asia South Asia Sub-S Africa L. Amer. & Carib.

Source: FAO, Statistics Division

Metalink: P4.ENV.FAO.CC.CE.YLD, p. 346

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PART 4

Biodiversity and conservationBiodiversity concerns the degree of variation of life formswithin a given ecosystem and is ultimately a measureof the health of ecosystems. Biodiversity for food andagriculture includes the components of biological diver-sity that are essential for feeding human populationsand improving the quality of life. It includes the varietyand variability of ecosystems, animals, plants and micro-organisms, at the genetic, species and ecosystem levels,which are necessary to sustain human life as well as thekey functions of ecosystems. Such diversity is the resultof thousands of years of farmers’ and breeders’ activities,land and forest utilization, and fisheries and aquacultureactivities combined with millions of years of natural se-lection. Much of the human population lives in areaswhere food production and nature co-exist together.

Agriculture’s main impacts on biodiversity are diverse.For instance, the expansion of agriculture can lead tolosses of natural wildlife habitat and reduction in thearea of natural forests, wetlands and so on, with an at-tendant loss of species. It also causes a general de-cline in species richness in forests, pastures and fieldmargins, and the reduction of wild genetic resources re-lated to domesticated crops and livestock. Moreover,the observed reduction of micro-organisms that helpsustain food and agricultural production is another waythat agriculture’s life support system has been damaged.The intensification of agricultural production is equallyputting biodiversity at risk.

The conservation and sustainable use of biodiversity forfood and agriculture plays a critical role in the fightagainst hunger, by ensuring environmental sustainabil-ity while increasing food and agriculture production. Itis imperative to do so in a sustainable way: harvestingresources without compromising the natural capital, in-cluding biodiversity and ecosystem services, and capital-izing on biological processes.

To achieve sustainable increases in productivity and pro-vide a sounder ecological basis for agriculture, a largereservoir of genetic and species diversity will need tobe maintained and sustainably used. The use of multi-species and multi-breed herds and flocks is one strat-egy that many traditional livestock farmers use to main-tain high diversity. Species combinations also enhanceproductivity in aquatic systems. Crop rotations, inter-cropping, alley farming and growing different varietiesof a single crop have all been shown to have beneficialeffects on crop performance, nutrient availability, pestand disease control and water management. Ensuringdiversity will help maintain and rehabilitate productiveecosystems to supply future generations with abundantfood and agriculture.

Further reading

• FAO Biodiversity (www.fao.org/biodiversity)• UN International Year of Biodiver-sity 2010 (www.fao.org/biodiversity/2010-international-year-of-biodiversity)

Map 64:

No Data < 5 5 − 10 10 − 20 20 − 30 > 30

Nationally protected areas, share of total area (%, 2009*)

Source: World Bank

Metalink: P4.ENV.WBK.WDI.CON.PROT, p. 350

→ 12.5 million hectares of the world’s landterrain is currently protected by law - butthis represents a fraction of the world’sland area

→ What is more, protected areas are par-ticularly scare in countries that applythemost intensive production systems inagriculture

306

BIODIVERSITY AND CONSERVATION

No Data < 5 5 − 10 10 − 20 20 − 30 > 30

Nationally protected areas, share of total area (%, 2009*)

Chart 115: A large number of animal and plant species threatened from human activityincluding the intensification of agriculture

Species threatened (2010)

Number

0

2000

4000

6000

8000

Fish species Mammal species Plant species

Source: World Bank

Metalink: P4.ENV.WBK.WDI.BIOD.PST, p. 350

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PART 4

Organic farming

Organic agriculture is a production management systemthat aims to promote and enhance ecosystem health, in-cluding biological cycles and soil biological activity. Itis based on minimizing the use of external inputs, andrepresents a deliberate attempt to make the best useof local natural resources. Methods are used to mini-mize pollution of air, soil and water. Organic agriculturecomprises a range of land, crop and animal managementprocedures, circumscribed by a set of rules and limitsusually enforced by inspection and certification mecha-nisms. Synthetic pesticides, mineral fertilizers, syntheticpreservatives, pharmaceuticals, Genetically Modified Or-ganisms (GMOs), sewage sludge and irradiation are pro-hibited in all organic standards.

Growth rates of land under organicmanagement inWest-ern Europe, Latin America and the Caribbean, and theUnited States of America have been impressive despitelow-base beginnings and the reclassification of land. Be-tween 1995 and 2010, the combined area of organic cul-tivation tripled to 38 million hectares. A number of in-dustrial countries have action plans for developing or-ganic agriculture. Targets are set for the sector’s growthand resources are allocated to compensate farmers dur-ing, and sometimes after, the conversion period, and alsoto support research and extension in organic agriculture.

Organic practices that encourage soil biological activ-ity and nutrient cycling include: manipulating crop ro-tations and strip cropping; green manuring and organicfertilization (animal manure, compost, crop residues),minimum tillage or zero tillage and avoidance of pes-ticide and herbicide use. Research indicates that organicagriculture significantly increases the density of benefi-cial invertebrates, earthworms, root symbionts and othermicro-organisms (fungi, bacteria). Properly managed or-ganic agriculture reduces or eliminates water pollutionand helps conserve water and soil on the farm.

At the international level, the general principles and re-quirements for organic agriculture are defined in theCodex Alimentarius guidelines adopted in 1999 and reg-ularly updated between 2001 and 2010. The growinginterest in organic crop, livestock and fish products ismainly driven by health and food quality concerns. How-ever, organic agriculture does not make a product claimthat its food is healthier or safer, but rather a processclaim intending to make food production and process-ing methods respectful of the environment.

Map 65:

No Data < 1 1 − 2 2 − 10 10 − 100 > 100

Organic agriculture area (thousand ha, 2009)

Source: FAO-FiBL-IFOAM

Metalink: P4.ENV.FAO.BIO.ORGAN.HA, p. 345

→ 38 million hectares of land were organi-cally farmed in 2009

→ Oceania has more area under organicfarming than any other region

308

ORGANIC FARMING

No Data < 1 1 − 2 2 − 10 10 − 100 > 100

Organic agriculture area (thousand ha, 2009)

Chart 116: Organic area rose by almost 30 percent in the second half of the last decade

World organic agriculture area (2004-09)

Millionha

28

30

32

34

2005 2006 2007 2008 2009

Source: FAO-FiBL-IFOAM

Metalink: P4.ENV.FAO.BIO.ORGAN.HA, p. 345

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Organic agriculture is not limited to certified organicfarms and products. Non-certified products can be in-cluded as long as they fully meet the requirements of or-ganic agriculture. This is the case for many non-certifiedorganic agricultural systems in both developing and in-dustrial countries where produce is consumed locally orsold directly on the farm or without labels.

Organic production systems can make important contri-butions to food supply stability and farmer livelihoodsby establishing soil fertility and providing diversity andthus resilience to food production systems in light ofthe many uncertainties of climate change. In particular,they contribute positively to food stability in terms of fer-tile and well-structured soils, improved water retention,protection of biodiversity with beneficial side effects onphytomedical (plant health) stability and nutrients andefficient water use.

Thus far, organic agriculture has proven to be a rela-tively cheap and practical option to address climate in-stability. This option is based on scientific evidence forcertain regions and extensive, though not scientificallydocumented, effective field application. Reports consis-tently show that organic systems have enhanced abilityto withstand droughts and floods and maintain high re-silience in the face of unpredictable impacts of climatechange.

The deficits of organic agriculture are mainly relatedto lower productivity. However, the deficits should notbe exaggerated. Significantly lower yields, those in therange of more than 20 to 30 percent compared to con-ventional agriculture, occur mostly in cash-crop-focusedproduction systems and under most favourable climateand soil conditions.

Further reading

• FAO Organic Agriculture (www.fao.org/organicag/en/)• FAO Organic Agriculture and Environmental Stabilityof the Food Supply - FAO (ftp://ftp.fao.org/docrep/fao/meeting/012/ah950e.pdf)

Map 66:

No Data < 0.5 0.5 − 1 1 − 5 5 − 10 > 10

Organic agriculture, share of total area (%, 2009)

Source: FAO-FiBL-IFOAM

Metalink: P4.ENV.FAO.BIO.ORGAN.SHA, p. 345

→ Despite significant growth in organicfarming, as a percentage of overall areacultivated, the sector remains minisculein comparison

→ In Europe the percentage of agriculturalarea allocated to organic farming rises tosingle digit levels, but elsewhere a frac-tion of a percentage point is common

310

ORGANIC FARMING

No Data < 0.5 0.5 − 1 1 − 5 5 − 10 > 10

Organic agriculture, share of total area (%, 2009)

Chart 117: Europe added an extra one million hectares of organically farmed area in2009

Regional organic agriculture area (2008-09)

Millionha

0

2

4

6

8

10

12

2008 2009

Africa Asia Europe Latin America Northern America Oceania

Source: FAO-FiBL-IFOAM

Metalink: P4.ENV.FAO.BIO.ORGAN.HA, p. 345

311