Editing IPCC:AR6/SROCC/Chapter-2 (section)

===== 2.3.1.3.2 Agriculture =====

High mountains have supported agricultural livelihoods for centuries. Rural communities are dependent on adequate levels of soil moisture at planting time, derived in part in many cases from irrigation water which includes glacier and snowmelt water; as a result, they are exposed to risk which stems from cryosphere changes ( ''high confidence'' ) (Figure 2.8). The relative poverty of many mountain communities contributes to their vulnerability to the impacts of these cryosphere changes (McDowell et al., 2014 <sup>[[#fn:r344|344]]</sup> ; Carey et al., 2017 <sup>[[#fn:r345|345]]</sup> ; Rasul and Molden, 2019 <sup>[[#fn:r346|346]]</sup> ) ''(medium evidence, high agreement).'' Glacier and snowmelt water contribute irrigation water to adjacent lowlands as well. Pastoralism, an important livelihood strategy in mountain regions, is also impacted by cryosphere changes, but described in Section 2.3.7.

There is ''medium evidence (medium agreement)'' that reduction in streamflow due to glacier retreat or reduced snow cover has led to reduced water availability for irrigation of crops and declining agricultural yields in several mountain areas (Table SM2.11), for example in the tropical Andes (e.g., Bury et al., 2011) and High Mountain Asia (e.g., Nüsser and Schmidt, 2017). In the Southern Andes, increased streamflow in the Elqui River in Chile, due to glacier retreat or changing snow cover, has led to increased water availability for irrigation and increased agricultural yields (Young et al., 2010 <sup>[[#fn:r347|347]]</sup> ).

In addition to the effects on agriculture of changing availability of irrigation water, reductions in snow cover can also impact agriculture through its direct effects on soil moisture, as reported for Nepal, where lesser snow cover has led to the drying of soils and lower yields of potatoes and fodder (Smadja et al., 2015 <sup>[[#fn:r348|348]]</sup> ). Agriculture in high mountain areas is sensitive to other climatic drivers as well. Rising air temperatures increase crop evapotranspiration, thus increasing water demand for crop production to maintain optimal yield (Beniston and Stoffel, 2014 <sup>[[#fn:r349|349]]</sup> ). They are also associated with upslope movement of cropping zones, which favours some farmers in high mountain areas, who are increasingly able to cultivate new crops, such as onions, garlic and apples in Nepal (Huntington et al., 2017 <sup>[[#fn:r350|350]]</sup> ; Hussain et al., 2018 <sup>[[#fn:r351|351]]</sup> ), and maize in Ecuador (Skarbø and VanderMolen, 2014 <sup>[[#fn:r352|352]]</sup> ). Dry spells and unseasonal frosts have also impacted agriculture in Peru (Bury et al., 2011 <sup>[[#fn:r353|353]]</sup> ).

Adaptation activities in mountain agriculture related at least partially to cryospheric changes are detailed in Table SM2.12 and their geographic spread shown in Figure 2.9. Agriculture in these areas is sensitive to non-climate drivers as well, such as market forces and political pressures (Montana et al., 2016 <sup>[[#fn:r354|354]]</sup> ; Sietz and Feola, 2016 <sup>[[#fn:r355|355]]</sup> ; Figueroa-Armijos and Valdivia, 2017 <sup>[[#fn:r356|356]]</sup> ) and shifts in water governance (Rasmussen, 2016). The majority of the adaptation activities are autonomous, though some are planned or carried out with support from national governments, non-governmental organisations (NGOs), or international aid organisations. Though many studies report on benefits from these activities which accrue to community members as increased harvests and income, systematic evaluations of these adaptation strategies are generally lacking. A range of factors, discussed below, place barriers which limit the scale and scope of these activities in the mountain agricultural sector, including a lack of finance and technical knowledge, low adaptive capacity within communities, ill-equipped state organisations, ambiguous property rights and inadequate institutional and market support ( ''medium evidence, high agreement'' ). Section 2.3.7 examines two other responses to decreasing irrigation water: wage labour migration, which often serves as an adaptation strategy, and displacement of entire communities, an indication of the limits to adaptation — this displacement is also due in some cases to natural hazards.

To cope with the reduced water supplies, planted areas have been reduced in a number of different places in Nepal (Gentle and Maraseni, 2012 <sup>[[#fn:r358|358]]</sup> ; Sujakhu et al., 2016 <sup>[[#fn:r359|359]]</sup> ). Adaptation responses within irrigation systems include the adoption of new irrigation technologies or upgrading existing technologies, adopting water conservation measures, water rationing, constructing water storage infrastructure, and change in cropping patterns (Rasul et al., 2019 <sup>[[#fn:r360|360]]</sup> ; Figure 2.9). Water delivery technologies which reduce loss are adopted in Chile (Young et al., 2010 <sup>[[#fn:r361|361]]</sup> ) and Peru (Orlove et al., 2019 <sup>[[#fn:r362|362]]</sup> ). Similarly, greenhouses have been adopted in Nepal (Konchar et al., 2015 <sup>[[#fn:r363|363]]</sup> ) to reduce evapotranspiration and frost damage, though limited access to finance is a barrier to these activities. Box 2.3 describes innovative irrigation practices in India. Local pastoral communities have responded to these challenges with techniques broadly similar to those in agricultural settings by expanding irrigation facilities, for example, in Switzerland (Fuhrer et al., 2014 <sup>[[#fn:r364|364]]</sup> ). In addition to adopting new technologies, some water users make investments to tap more distant sources of irrigation water. Cross-Chapter Box 3 in Chapter 1 discusses such efforts in Northern Pakistan, where landslides, associated with cryosphere change, have also damaged irrigation systems.

The adoption of new crops and varieties is an adaptation response found in several regions. Farmers in northwest India have increased production of lentils and vegetables, which provide important nutrients to the local diet, with support from government watershed improvement programs which help address decreased availability of irrigation water, though stringent requirements for participation in the programs have limited access by poor households to this assistance (Dame and Nüsser, 2011 <sup>[[#fn:r365|365]]</sup> ). Farmers who rely on irrigation in the Naryn River basin in Kyrgyzstan have shifted from the water intensive fruits and vegetables to fodder crops such as barley and alfalfa, which are more profitable. Upstream communities, with greater access to water and more active local institutions, are more willing to experiment with new crops than those further downstream (Hill et al., 2017 <sup>[[#fn:r366|366]]</sup> ). In other areas, crop choices also reflect responses to rising temperatures along with new market opportunities such as the demand for fresh vegetables by tourists in Nepal (Konchar et al., 2015 <sup>[[#fn:r367|367]]</sup> ; Dangi et al., 2018 <sup>[[#fn:r368|368]]</sup> ) and the demand for roses in urban areas in Peru (SENASA, 2017 <sup>[[#fn:r369|369]]</sup> ). Indigenous knowledge and local knowledge (Cross-Chapter Box 4 in Chapter 1), access to local and regional seed supply networks, proximity to agricultural extension and support services also facilitate the adoption of new crops (Skarbø and VanderMolen, 2014 <sup>[[#fn:r370|370]]</sup> ).

Local institutions and embedded social relations play a vital role in enabling mountain communities to respond to the impacts of climate driven cryosphere change. Indigenous pastoral communities who have tapped into new water sources to irrigate new areas in Peru have also strengthened the control of access to existing irrigated pastures (Postigo, 2014 <sup>[[#fn:r371|371]]</sup> ) and Bolivia (Yager, 2015 <sup>[[#fn:r372|372]]</sup> ). In an example of indigenous populations in the USA, two tribes who share a large reservation in the Northern Rockies rely on rivers which receive glacier melt water to irrigate pasture, and maintain fisheries, domestic water supplies, and traditional ceremonial practices. Tribal water managers have sought to install infrastructure to promote more efficient water use and protect fisheries, but these efforts have been impeded by land and water governance institutions in the region and by a history of social marginalisation (McNeeley, 2017 <sup>[[#fn:r373|373]]</sup> ).

High mountain communities have sought new financial resources from wage labour (Section 2.3.7), tourism (Mukherji et al., 2019 <sup>[[#fn:r374|374]]</sup> ) and government sources to support adaptation activities. Local water user associations in Kyrgyzstan and Tajikistan have adopted less water intensive crops and reorganised the use and maintenance of irrigation systems, investing government relief payments after floods (Stucker et al., 2012 <sup>[[#fn:r375|375]]</sup> ). Similar measures are reported from India and Pakistan (Dame and Mankelow, 2010 <sup>[[#fn:r376|376]]</sup> ; Clouse, 2016 <sup>[[#fn:r377|377]]</sup> ; Nüsser and Schmidt, 2017 <sup>[[#fn:r378|378]]</sup> ), Nepal (McDowell et al., 2013 <sup>[[#fn:r379|379]]</sup> ) and Peru (Postigo, 2014 <sup>[[#fn:r380|380]]</sup> ). In contrast, fewer adaptation measures have been adopted in Uzbekistan, due to low levels of capital availability and to agricultural policies, including centralised water management, crop production quotas and weak agricultural extension, which limit the response capacity of farmers (Aleksandrova et al., 2014 <sup>[[#fn:r381|381]]</sup> ).

Lowland agricultural areas which receive irrigation water from rivers fed by glacier melt and snowmelt are projected to face negative impacts in some regions ( ''limited evidence, high agreement'' ). In the Rhone basin in Switzerland, many irrigated pasture areas are projected to face water deficits by 2050, under the A1B scenario (Fuhrer et al., 2014 <sup>[[#fn:r382|382]]</sup> ; Cross Chapter Box 1 in Chapter 1). For California and the southwestern USA, a shift to peak snowmelt earlier in the year would create more frequent floods, and a reduced ability of existing reservoirs to store water by 2050 under RCP8.5 (Pagán et al., 2016 <sup>[[#fn:r383|383]]</sup> ) and by 2100 under RCP2.6, RCP4.5 and RCP8.5 (Pathak et al., 2018 <sup>[[#fn:r374|374]]</sup> ). The economic values of these losses have been estimated at 10.8 – 48.6 billion USD by around 2050 (Sturm et al., 2017 <sup>[[#fn:r385|385]]</sup> ). A similar transition to runoff peaks earlier in the year by 2100 under RCP2.6, RCP4.5 and RCP8.5, creating challenges for management of irrigation water, has been reported for the countries in central Asia which are dependent on snow cover and glaciers of the Tien Shan (Xenarios et al., 2018 <sup>[[#fn:r386|386]]</sup> ). In India and Pakistan, where over 100 million farmers receive irrigation from the Indus and Ganges Rivers, which also have significant inputs from glaciers and snowmelt, also face risks of decreasing water supplies from cryosphere change by 2100 (Biemans et al., 2019 <sup>[[#fn:r387|387]]</sup> ; Rasul and Molden, 2019 <sup>[[#fn:r388|388]]</sup> ).

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