Scenario Projections of the Changes in Water Availability to Wheat Crops in the Steppe Crimea in the 21st Century and Some Measures Increasing the Efficiency of Its Cultivation

Abstract. Water scarcity conditions over the 21st century both globally and regionally are assessed in the context of climate change and climate mitigation policies, by estimating both water availability and water demand within the Global Change Assessment Model (GCAM), a leading community-integrated assessment model of energy, agriculture, climate, and water. To quantify changes in future water availability, a new gridded water-balance global hydrologic model – namely, the Global Water Availability Model (GWAM) – is developed and evaluated. Global water demands for six major demand sectors (irrigation, livestock, domestic, electricity generation, primary energy production, and manufacturing) are modeled in GCAM at the regional scale (14 geopolitical regions, 151 sub-regions) and then spatially downscaled to 0.5° × 0.5° resolution to match the scale of GWAM. Using a baseline scenario (i.e., no climate change mitigation policy) with radiative forcing reaching 8.8 W m−2 (equivalent to the SRES A1Fi emission scenario) and three climate policy scenarios with increasing mitigation stringency of 7.7, 5.5, and 4.2 W m−2 (equivalent to the SRES A2, B2, and B1 emission scenarios, respectively), we investigate the effects of emission mitigation policies on water scarcity. Two carbon tax regimes (a universal carbon tax (UCT) which includes land use change emissions, and a fossil fuel and industrial emissions carbon tax (FFICT) which excludes land use change emissions) are analyzed. The baseline scenario results in more than half of the world population living under extreme water scarcity by the end of the 21st century. Additionally, in years 2050 and 2095, 36% (28%) and 44% (39%) of the global population, respectively, is projected to live in grid cells (in basins) that will experience greater water demands than the amount of available water in a year (i.e., the water scarcity index (WSI) > 1.0). When comparing the climate policy scenarios to the baseline scenario while maintaining the same baseline socioeconomic assumptions, water scarcity declines under a UCT mitigation policy but increases with a FFICT mitigation scenario by the year 2095, particularly with more stringent climate mitigation targets. Under the FFICT scenario, water scarcity is projected to increase, driven by higher water demands for bio-energy crops.

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Integrated assessment of global water scarcity over the 21st century – Part 1: Global water supply and demand under extreme radiative forcing

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-10-3327-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 3327-3381 ◽

Cited By ~ 10

Author(s):

M. I. Hejazi ◽

J. Edmonds ◽

L. Clarke ◽

P. Kyle ◽

E. Davies ◽

...

Keyword(s):

21St Century ◽

Water Availability ◽

Water Scarcity ◽

Water Demand ◽

Integrated Assessment ◽

Radiative Forcing ◽

Assessment Model ◽

Water Demands ◽

Global Population ◽

Global Water

Abstract. Water scarcity conditions over the 21st century both globally and regionally are assessed in the context of climate change, by estimating both water availability and water demand within the Global Change Assessment Model (GCAM), a leading community integrated assessment model of energy, agriculture, climate, and water. To quantify changes in future water availability, a new gridded water-balance global hydrologic model – namely, the Global Water Availability Model (GWAM) – is developed and evaluated. Global water demands for six major demand sectors (irrigation, livestock, domestic, electricity generation, primary energy production, and manufacturing) are modeled in GCAM at the regional scale (14 geopolitical regions, 151 sub-regions) and then spatially downscaled to 0.5° × 0.5° resolution to match the scale of GWAM. Using a baseline scenario (i.e., no climate change mitigation policy) with radiative forcing reaching 8.8 W m−2 (equivalent to the SRES A1Fi emission scenario) and a global population of 14 billion by 2095, global annual water demand grows from about 9–10% of total annual renewable freshwater in 2005 to about 32–37% by 2095. This results in more than half of the world population living under extreme water scarcity by the end of the 21st century. Regionally, the demand for water exceeds the amount of water availability in two GCAM regions, the Middle East and India. Additionally, in years 2050 and 2095 36% (28%) and 44% (39%) of the global population, respectively is projected to live in grid cells (in basins) that will experience greater water demands than the amount of available water in a year (i.e., the water scarcity index (WSI) > 1.0). This study implies an increasingly prominent role for water in future human decisions, and highlights the importance of including water in integrated assessment of global change.

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Climate change vs. socio-economic development: Understanding the future South-Asian water gap

10.5194/hess-2018-16 ◽

2018 ◽

Author(s):

René R. Wijngaard ◽

Hester Biemans ◽

Arthur F. Lutz ◽

Arun B. Shrestha ◽

Philippus Wester ◽

...

Keyword(s):

Climate Change ◽

Economic Development ◽

South Asian ◽

21St Century ◽

Water Availability ◽

Water Demand ◽

River Basins ◽

Socio Economic Development ◽

The Future ◽

Asian Water

Abstract. The Indus, Ganges, and Brahmaputra (IGB) river basins provide about 900 million people with water resources used for agricultural, domestic, and industrial purposes. These river basins are marked as climate change hotspot, where climate change is expected to affect monsoon dynamics and the amount of meltwater from snow and ice, and thus the amount of water available. Simultaneously, rapid and continuous population growth, and strong economic development will likely result in a rapid increase in water demand. Since quantification of these future trends is missing, it is rather uncertain how the future South Asian water gap will develop. To this end, we assess the combined impacts of climate change and socio-economic development on future blue water scarcity for the IGB until the end of the 21st century. We apply a coupled modelling approach consisting of the distributed cryospheric-hydrological model SPHY, which simulates current and future upstream water supply, and the hydrology and crop production model LPJmL, which simulates current and future downstream water supply and demand. We force the models with an ensemble of eight representative downscaled General Circulation Models (GCMs) that are selected from the RCP4.5 and RCP8.5 scenarios, and a set of land use and socio-economic scenarios that are consistent with the Shared Socio-economic Pathway (SSP) marker scenarios 1 and 3. The simulation outputs are used to analyse changes in water availability, supply, demand, and scarcity. The outcomes show an increase in surface water availability towards the end of the 21st century, which can mainly be attributed to increases in monsoon precipitation. However, despite the increase surface water availability, the strong socio-economic development and associated increase in water demand will likely lead to an increase in the water gap during the 21st century. This indicates that socio-economic development is the key driver in the evolution of the future South Asian water gap.

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Climate change vs. socio-economic development: understanding the future South Asian water gap

Hydrology and Earth System Sciences ◽

10.5194/hess-22-6297-2018 ◽

2018 ◽

Vol 22 (12) ◽

pp. 6297-6321 ◽

Cited By ~ 15

Author(s):

René Reijer Wijngaard ◽

Hester Biemans ◽

Arthur Friedrich Lutz ◽

Arun Bhakta Shrestha ◽

Philippus Wester ◽

...

Keyword(s):

Climate Change ◽

Economic Development ◽

South Asian ◽

21St Century ◽

Water Availability ◽

River Basins ◽

Environmental Flow ◽

Socio Economic Development ◽

The Future ◽

Asian Water

Abstract. The Indus, Ganges, and Brahmaputra (IGB) river basins provide about 900 million people with water resources used for agricultural, domestic, and industrial purposes. These river basins are marked as “climate change hotspots”, where climate change is expected to affect monsoon dynamics and the amount of meltwater from snow and ice, and thus the amount of water available. Simultaneously, rapid and continuous population growth as well as strong economic development will likely result in a rapid increase in water demand. Since quantification of these future trends is missing, it is rather uncertain how the future South Asian water gap will develop. To this end, we assess the combined impacts of climate change and socio-economic development on the future “blue” water gap in the IGB until the end of the 21st century. We apply a coupled modelling approach consisting of the distributed cryospheric–hydrological model SPHY, which simulates current and future upstream water supply, and the hydrology and crop production model LPJmL, which simulates current and future downstream water supply and demand. We force the coupled models with an ensemble of eight representative downscaled general circulation models (GCMs) that are selected from the RCP4.5 and RCP8.5 scenarios, and a set of land use and socio-economic scenarios that are consistent with the shared socio-economic pathway (SSP) marker scenarios 1 and 3. The simulation outputs are used to analyse changes in the water availability, supply, demand, and gap. The outcomes show an increase in surface water availability towards the end of the 21st century, which can mainly be attributed to increases in monsoon precipitation. However, despite the increase in surface water availability, the strong socio-economic development and associated increase in water demand will likely lead to an increase in the water gap during the 21st century. This indicates that socio-economic development is the key driver in the evolution of the future South Asian water gap. The transgression of future environmental flows will likely be limited, with sustained environmental flow requirements during the monsoon season and unmet environmental flow requirements during the low-flow season in the Indus and Ganges river basins.

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Water availability change in central Belgium for the late 21st century

Global and Planetary Change ◽

10.1016/j.gloplacha.2015.05.012 ◽

2015 ◽

Vol 131 ◽

pp. 115-123 ◽

Cited By ~ 29

Author(s):

Hossein Tabari ◽

Meron Teferi Taye ◽

Patrick Willems

Keyword(s):

21St Century ◽

Water Availability ◽

Late 21St Century

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Climate change impacts on snow water availability in the Euphrates-Tigris basin

Hydrology and Earth System Sciences ◽

10.5194/hess-15-2789-2011 ◽

2011 ◽

Vol 15 (9) ◽

pp. 2789-2803 ◽

Cited By ~ 18

Author(s):

M. Özdoğan

Keyword(s):

Climate Change ◽

Water Resources ◽

Snow Cover ◽

21St Century ◽

Water Availability ◽

Greenhouse Gas Emission ◽

Climate Change Impacts ◽

Hydrologic Model ◽

Macro Scale ◽

Snow Water

Abstract. This study investigates the effects of projected climate change on snow water availability in the Euphrates-Tigris basin using the Variable Infiltration Capacity (VIC) macro scale hydrologic model and a set of regional climate-change outputs from 13 global circulation models (GCMs) forced with two greenhouse gas emission scenarios for two time periods in the 21st century (2050 and 2090). The hydrologic model produces a reasonable simulation of seasonal and spatial variation in snow cover and associated snow water equivalent (SWE) in the mountainous areas of the basin, although its performance is poorer at marginal snow cover sites. While there is great variation across GCM outputs influencing snow water availability, the majority of models and scenarios suggest a significant decline (between 10 and 60 percent) in available snow water, particularly under the high-impact A2 climate change scenario and later in the 21st century. The changes in SWE are more stable when multi-model ensemble GCM outputs are used to minimize inter-model variability, suggesting a consistent and significant decrease in snow-covered areas and associated water availability in the headwaters of the Euphrates-Tigris basin. Detailed analysis of future climatic conditions point to the combined effects of reduced precipitation and increased temperatures as primary drivers of reduced snowpack. Results also indicate a more rapid decline in snow cover in the lower elevation zones than the higher areas in a changing climate but these findings also contain a larger uncertainty. The simulated changes in snow water availability have important implications for the future of water resources and associated hydropower generation and land-use management and planning in a region already ripe for interstate water conflict. While the changes in the frequency and intensity of snow-bearing circulation systems or the interannual variability related to climate were not considered, the simulated changes in snow water availability presented here are likely to be indicative of climate change impacts on the water resources of the Euphrates-Tigris basin.

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Climate change impacts on snow water availability in the Euphrates-Tigris basin

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-8-3631-2011 ◽

2011 ◽

Vol 8 (2) ◽

pp. 3631-3666 ◽

Cited By ~ 3

Author(s):

M. Özdoğan

Keyword(s):

Climate Change ◽

Water Resources ◽

Snow Cover ◽

21St Century ◽

Water Availability ◽

Greenhouse Gas Emission ◽

Climate Change Impacts ◽

Hydrologic Model ◽

Macro Scale ◽

Snow Water

Abstract. This study investigates the effects of projected climate change on snow water availability in the Euphrates-Tigris basin using the Variable Infiltration Capacity (VIC) macro scale hydrologic model and a set of regional climate-change outputs from 13 global circulation models (GCMs) forced with two greenhouse gas emission scenarios for two time periods in the 21st century (2050 and 2090). The hydrologic model produces a reasonable simulation of seasonal and spatial variation in snow cover and associated snow water equivalent (SWE) in the mountainous areas of the basin, although its performance is poorer at marginal snow cover sites. While there is great variation across GCM outputs influencing snow water availability, the majority of models and scenarios suggest a significant decline (between 10 and 60 percent) in available snow water, particularly under the aggressive A2 climate change scenario and later in the 21st century. The changes in SWE are more stable when multi-model ensemble GCM outputs are used to minimize inter-model variability, suggesting a consistent and significant decrease in snow-covered areas and associated water availability in the headwaters of the Euphrates Tigris basin. Detailed analysis of future climatic conditions point to the combined effects of reduced precipitation and increased temperatures as primary drivers of reduced snowpack. Results also indicate a more rapid decline in snow cover in the lower elevation zones than the higher areas in a changing climate. The simulated changes in snow water availability have important implications for the future of water resources and associated hydropower generation and land-use management and planning in a region already ripe for interstate water conflict. While the changes in the frequency and intensity of snow-bearing circulation systems or the interannual variability related to climate were not considered, the simulated changes in snow water availability presented here are likely to be indicative of climate change impacts on the water resources of the Euphrates-Tigris basin.

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Less reliable water availability in the 21st century climate projections

Earth s Future ◽

10.1002/2013ef000159 ◽

2014 ◽

Vol 2 (3) ◽

pp. 152-160 ◽

Cited By ~ 33

Author(s):

Sanjiv Kumar ◽

David M. Lawrence ◽

Paul A. Dirmeyer ◽

Justin Sheffield

Keyword(s):

21St Century ◽

Water Availability ◽

Climate Projections

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Response of evapotranspiration and water availability to changing climate and land cover on the Mongolian Plateau during the 21st century

Global and Planetary Change ◽

10.1016/j.gloplacha.2013.06.008 ◽

2013 ◽

Vol 108 ◽

pp. 85-99 ◽

Cited By ~ 47

Author(s):

Yaling Liu ◽

Qianlai Zhuang ◽

Min Chen ◽

Zhihua Pan ◽

Nadja Tchebakova ◽

...

Keyword(s):

Land Cover ◽

21St Century ◽

Water Availability ◽

Mongolian Plateau ◽

Changing Climate

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A simple tool for refining GCM water availability projections, applied to Chinese catchments

Hydrology and Earth System Sciences ◽

10.5194/hess-22-6043-2018 ◽

2018 ◽

Vol 22 (11) ◽

pp. 6043-6057

Author(s):

Joe M. Osborne ◽

F. Hugo Lambert

Keyword(s):

21St Century ◽

River Runoff ◽

Water Availability ◽

Climate Models ◽

Yellow River ◽

Human Impacts ◽

Global Climate ◽

Regional Scale ◽

Global Climate Models

Abstract. There is a growing desire for reliable 21st-century projections of water availability at the regional scale. Global climate models (GCMs) are typically used together with global hydrological models (GHMs) to generate such projections. GCMs alone are unsuitable, especially if they have biased representations of aridity. The Budyko framework represents how water availability varies as a non-linear function of aridity and is used here to constrain projections of runoff from GCMs, without the need for computationally expensive GHMs. Considering a Chinese case study, we first apply the framework to observations to show that the contribution of direct human impacts (water consumption) to the significant decline in Yellow River runoff was greater than the contribution of aridity change by a factor of approximately 2, although we are unable to rule out a significant contribution from the net effect of all other factors. We then show that the Budyko framework can be used to narrow the range of Yellow River runoff projections by 34 %, using a multi-model ensemble and the high-end Representative Concentration Pathway (RCP8.5) emissions scenario. This increases confidence that the Yellow River will see an increase in runoff due to aridity change by the end of the 21st century. Yangtze River runoff projections change little, since aridity biases in GCMs are less substantial. Our approach serves as a quick and inexpensive tool to rapidly update and correct projections from GCMs alone. This could serve as a valuable resource when determining the water management policies required to alleviate water stress for future generations.

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