Climate-Cryosphere-Water Nexus Central Asia Outlook Vital roles of mountains, snow and glaciers Elevation Water is held as ice that melts in summer Snow 5000 m Water is held as snow Rain & snow that melts in spring Glacier 3000 m Permafrost Glacial lake, Water runs off with potential for within a few days outburst flood 1000 m Mainly rain This summary has been prepared under request of the Climate Change and Environment (CC&E) Network of the Swiss Agency for Development and Cooperation (SDC) Introduction Regional demand for water resources The three components of the cryosphere – glaciers, snow and permafrost – are all af- Fresh water was once a relatively secure re- by changing the dynamics of seasonal water fected by climate change. Mountain commu- source, but economic development and ex- distribution and availability to downstream nities face growing risks to infrastructure, panding population are resulting in growing countries (Bernauer et al. 2012, Internation- while downstream communities face disrup- demand for water resources for food and al Crisis Group 2014). More water was com- tions in their water supply and risks of food power production, and for industrial and ing to downstream areas in winter, when it and energy insecurity as a consequence. In municipal uses. The competing demands for U?QLMRPC?JJWLCCBCB?LBA?SQCBkMMBGLE Central Asia, the cryosphere-related chang- water resources between sectors and coun- while less water was available in summer, es in water resources will be strongest in the tries are expected to grow. when agriculture needs it most. In periods of second half of the century, as glaciers shrink BPMSEFRQ RFC U?RCP BCjAGR GL QSKKCP U?Q and the extent and duration of snow declines particularly damaging, and local people suf- considerably toward the end of the century !MMNCP?RGMLMPAMLkGAR fered losses. Recently Uzbekistan and Tajik- (IPCC 2014). GQR?LF?TCQGEL?JCBRFCGPUGJJGLELCQQRMjLB In the Soviet era, in exchange for fossil fuel solutions to the recurring interstate water Temperature increases in Central Asia are and power supply during the winter months, disputes through dialogue, and other coun- projected to exceed the global climate policy the upstream countries of Tajikistan and RPGCQF?TCGLRCLQGjCB@GJ?RCP?J?LBPCEGML?J target, and combined with cryosphere-relat- Kyrgyzstan – major glacial centers and key cooperation. ed changes may seriously affect water and sources of water resources for Central Asia other natural resources as well as weath- – provided the downstream countries of Ka- Glaciers of Central Asia are essentially natu- er-dependent sectors such as public health, zakhstan, Turkmenistan and Uzbekistan with ral reservoirs that accumulate and store wa- hydropower and agriculture. The socioeco- a reliable source of water for reliable irriga- ter from winter and spring precipitation and nomic implications of the projected climate tion in the summer. release it in summer, when rainfall is low and and cryosphere changes are not well under- water demand is high. In the face of ongo- stood, but lives and livelihoods clearly hang After independence, the water-for-ener- ing climate change, the challenges related in the balance, and the region needs to gy exchange system collapsed, and the up- to water management may recur and persist. strengthen its climate and glacier monitoring stream countries changed the operations of Adaptation to the new climate and water re- and assessment and take diverse adaptation their dams to produce more hydropower in alities is central to the region’s prospects for measures to respond to the risks. winter to ensure their energy security, there- ?TMGBGLEAMLkGARQMTCPQA?PACPCQMSPACQ Climate change in the region Temperature and precipitation In Central Asia, temperatures have increased is most pronounced in the Tien Shan and at steadily over the last 50 years, with more pro- lower elevations of the Pamir-Alai Mountains. nounced warming over the winter months, and Many small glaciers have already disappeared. in the valleys and lowlands (Unger-Shayesteh et Central Asia glaciers al. 2013). Compared to the climatic conditions in Glacier mass balance measurements show loss- Cumulative mass balance, millimeters of water equivalent 2500 the 1950-1980 period, temperatures are project- es close to 30 per cent since the 1960s, with an 0 ed to rise by 2.5°C-6.5°C towards the end of the accelerated glacier mass loss since 2000 similar 1957 century. The exact outcome depends on the glob- to many other regions worldwide. In the Tien -5000 al greenhouse gases emission pathways, which Shan mountains, for instance, about 3000 km2 Urumqi No. 1 range from robust mitigation reducing emissions of glacier area was lost during this period. The -10000 Abramov almost to zero to a relaxed attitude leading to rap- future melting of glaciers in Central Asia will Golubin id and steady climate warming (Reyer et al. 2017). vary by altitude, but more than 50 per cent -15000 Kara-Batkak of the current glacier mass is expected to be M. Mametova Igli Tuyuksu Changes in precipitation in Central Asia vary by lost by the end of the century (Luz et al. 2013, -20000 Ts. Tuyuksu topography and locality, but the lack of consist- Sorg et al. 2014, Huss & Hock 2015). With such -25000 ent monitoring limits the analysis. Projections substantial reductions in glacier cover and ice 1950 1960 1970 1980 1990 2000 2010 2017 suggest that south-west areas of the region may reserves, and changes in snow and rainfall pat- become drier, while north-east regions and the RCPL PGTCP kMU T?PG?@GJGRW K?W GLAPC?QC ?LB neighboring western China hinterlands may be- QC?QML?JU?RCPkMUK?WAF?LEC Source: World Glacier Monitoring Centre (2018) come wetter. Glaciers, snow and Length & tongue Mass balance Number and area permafrost The changes in Elevation glaciers are 4500 Climate warming accelerates the melting of snow, glaciers and permafrost, affecting the overall wa- captured by 4000 Melt water equivalent, mm ter balance. Higher temperatures reduce snow measures of 3500 cover and depth, shorten the duration of cover, size and mass + Gain and shift the distribution of areas with permanent 0 snow and frozen soil and rocks to higher altitudes. 3000 balance. Length 50 years ago - Loss The glaciers in Central Asia are retreating at 0 510km present time different rates in different areas. The shrinkage Water availability Glaciers and seasonal snow pack of the Tien Shan and Pamir mountains provide about half of the Accelerating Peak water Most glaciers QRPC?K kMU RM RFC KS "?PW? ?LB 1WP "?PW? Water flow glacial melt from glaciers vanish rivers, and the year-to-year amount of fresh water +1° +2° may vary with climatic conditions. The volume, increases with +6° depth and extent of snow determines the timing glacial melting, MDRFCQLMUKCJRAMLRPG@SRGMLRMPGTCPkMU then declines As the climate warms and the glaciers shrink, when the +50% +50% annual run-off, and especially the glacial melt floods AMLRPG@SRGMLRMRFCPGTCPkMU UGJJGLGRG?JJWGL glaciers Less reliable water supply summer flow in summer crease, then peak and subsequently decline. are gone. Increased water evaporation from soils and plants in a warmer climate will exacerbate this present time next 20-30 years (2050) end of century (2100) decline. Widespread permafrost thawing and the appearance of glacier lakes increase the risk of rock instability and failure, and present threats to downstream communities and crit- ical infrastructure, such as roads and mines. Sound water resources planning and effective With glacier Without glacier More pronounced risk management will depend on an under- water fluctuations standing and consideration of these dynamics. As glaciers Central Asia run-off projections until about retreat, 2030 show no major expected changes, but the water flow Years a number of studies agree that changes in glacier and snow melt will result in a shift of peak shifts Summer Spring Seasonal shift in flow peak flow peak water availability seasonal water peak from summer to spring, from summer to with locally different peaks for individual catchments. The annual peak water is expect- spring. ed around 2050, and by the end of the cen- tury, run-off is likely to decline in all Central JFMAMJJASOND JFMAMJJASOND JFMAMJJASOND Asia river basins (Sorg et al. 2014, Reyer et al. 2017, Huss & Hock 2018). Floods, flash floods Slope instability Downstream water shortages and inundations and slides and diminished water quality The changes in the mountains carry risks all the way to the lowlands. Overall, Central Asia is considered a global While in-depth understanding of the socio- climate and the cryosphere (Unger-Shayesteh hotspot region with respect to impacts of economic impacts of climate and cryos phere et al. 2013). Without a strong data basis, fu- climate change on the mountain cryosphere changes is still incomplete and should be ad- ture trends that might support decision-mak- and downstream societies, most notably for dressed in the region, the direction of chang- GLEUGJJ@CBGDjASJRRM?QQCQQ ARGMLQ?PC@C water resources and risks from natural haz- es is robust. Flexibility in river basin manage- GLE SLBCPR?ICL RM DSJjJJ RFC M@QCPT?RGML?J ards. While cryosphere related changes in ment plans with consideration of climate gaps of the last 30 years and to support new water resources will be less strong in the impacts and risk reduction measures become generations of hydrometeorologists, climate next one to two decades, major changes are very important. Intensifying local adap ta tion and glacier scientists and water planners (Ho- expected later in the century as glaciers be- efforts will be a key to avoiding climate risks elzle et al. 2017). The international commu- come increasingly smaller and snow extent that go beyond critical levels, as will the co- nity is working together with national and and duration decrease. A particular concern ordination of cross-border adaptation efforts.