scholarly journals Integrated assessment of global water scarcity over the 21st century under multiple climate change mitigation policies

2014 ◽  
Vol 18 (8) ◽  
pp. 2859-2883 ◽  
Author(s):  
M. I. Hejazi ◽  
J. Edmonds ◽  
L. Clarke ◽  
P. Kyle ◽  
E. Davies ◽  
...  
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Water Availability ◽  
Water Scarcity ◽  
Carbon Tax ◽  
Assessment Model ◽  
Baseline Scenario ◽  
Water Demands ◽  
Global Water ◽  
Mitigation Policies

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.

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

2013 ◽  
Vol 10 (3) ◽  
pp. 3327-3381 ◽  
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.

scholarly journals Integrated assessment of global water scarcity over the 21st century – Part 2: Climate change mitigation policies

2013 ◽  
Vol 10 (3) ◽  
pp. 3383-3425 ◽  
Author(s):  
M. I. Hejazi ◽  
J. Edmonds ◽  
L. Clarke ◽  
P. Kyle ◽  
E. Davies ◽  
...  
Keyword(s):  
Land Use ◽  
Water Scarcity ◽  
Integrated Assessment ◽  
Climate Change Mitigation ◽  
Carbon Tax ◽  
Assessment Model ◽  
Baseline Scenario ◽  
Mitigation Policy ◽  
Change Mitigation ◽  
Mitigation Policies

Abstract. We investigate the effects of emission mitigation policies on water scarcity both globally and regionally using the Global Change Assessment Model (GCAM), a leading community integrated assessment model of energy, agriculture, climate, and water. Three climate policy scenarios with increasing mitigation stringency of 7.7, 5.5, and 4.2 W m−2 in year 2095 (equivalent to the SRES A2, B2, and B1 emission scenarios, respectively), under 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 results are compared to 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) by 2095. When compared to the baseline scenario and 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. The decreasing trend with UCT policy stringency is due to substitution from more water-intensive to less water-intensive choices in food and energy production, and in land use. Under the FFICT scenario, water scarcity is projected to increase driven by higher water demands for bio-energy crops. This study implies an increasingly prominent role for water availability in future human decisions, and highlights the importance of including water in integrated assessment of global change. Future research will be directed at incorporating water shortage feedbacks in GCAM to better understand how such stresses will propagate across the various human and natural systems in GCAM.

scholarly journals The water-food-energy-land nexus: Hotspots and scenario-dependency of competition for water between energy, food and nature

2020 ◽  
Author(s):  
Lotte de Vos ◽  
Hester Biemans ◽  
Jonathan Doelman ◽  
Elke Stehfest
Keyword(s):  
Climate Change ◽  
Climate Change Mitigation ◽  
Freshwater Ecosystems ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Food Energy ◽  
Water Demands ◽  
Water Energy Nexus ◽  
Change Mitigation ◽  
Global Water

<p>Freshwater is a shared resource needed both for food and energy production, and to sustain  ecosystems worldwide. Freshwater ecosystems are already experiencing biodiversity declines that are higher than in most terrestrial systems. With climate change and an expected increase in global population and income, the trade-offs between societal demand and nature become even more stringent. Insight in how these developments might impact future water use helps to identify strategies to ensure a healthy environment while still meeting global water demands. </p><p>This study evaluates competition for water within the food-water-energy nexus, while explicitly accounting for the amount of water required by nature. It does so by implementation of Environmental Flow Requirements (EFRs), which are in this case defined as the quantity and timing  of  water  flows  required  to  sustain  freshwater  and  estuarine ecosystems. Simulations are performed with the integrated assessment model framework IMAGE, which includes the global vegetation and hydrology model LPJmL.  This framework combines regional agro-economic, energy and climate policy modelling with land-use, dynamic vegetation and hydrological modelling. </p><p>Different pathways of socio-economic developments (Shared Socio-economic Pathways (SSPs)) are evaluated up until the year 2100, including a climate change mitigation scenario aiming for the long-term mitigation target of 2 °C. Earlier studies for SSP-1, SSP-2 and SSP-3 have already shown that while global water withdrawals are expected to increase for all cases, the demands for SSP-3 are generally higher than the demands for SSP-1. This study adds to this by showing how water demands affect environmental flows, or vice versa. The results present an overview of hotspots where future water demand for food, energy and nature might still compete, and where the effects are ameliorated if the world will develop towards a more sustainable path. Additionally, the results present how irrigation efficiency improvements and climate change mitigation measures can help alleviate the pressure in the food-water-energy nexus, although the latter depends on the choice of mitigation pathway. </p>

A CGE Analysis of the Effects of Global Climate Change Mitigation Policies on India

2018 ◽  
pp. 573-590
Author(s):  
Basanta K. Pradhan ◽  
Joydeep Ghosh
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Climate Change Mitigation ◽  
Carbon Tax ◽  
Global Climate ◽  
Value Added ◽  
Low Carbon ◽  
Mitigation Policy ◽  
Change Mitigation ◽  
Mitigation Policies

This paper compares the effects of a global carbon tax and a global emissions trading regime on India using a dynamic CGE framework. The sensitivity of the results to the value of a crucial elasticity parameter is also analysed. The results suggest that the choice of the mitigation policy is relatively unimportant from an efficiency perspective. However, the choice of the mitigation policy and the value of the substitution elasticity between value added and energy were found to be important determinants of welfare effects. Global climate change mitigation policies have the potential for promoting low carbon and inclusive growth in India.

Water scarcity and food security: alternative futures for the 21st century

2001 ◽  
Vol 43 (4) ◽  
pp. 61-70 ◽  
Author(s):  
M. W. Rosengrant ◽  
X. Cai
Keyword(s):  
Food Security ◽  
Water Availability ◽  
Water Scarcity ◽  
Food Production ◽  
Irrigated Agriculture ◽  
Modeling Framework ◽  
Alternative Futures ◽  
Water Demands ◽  
Agriculture And Food

Water availability for agriculture - the major water user worldwide - is one of the most critical factors for food security in many regions of the world. The role of water withdrawals in irrigated agriculture and food security has been receiving substantial attention in recent years. This paper addresses key questions regarding water availability and food security, including: How will water availability and water demand evolve over the next three decades, taking into account availability and variability in water resources, the water supply infrastructure, and irrigation and nonagricultural water demands? What are the relationships among water scarcity, food production, and food security? How much of future food production will come from rainfed and irrigated areas? A global modeling framework, IMPACT-Water, is applied to explore answers to these questions using analysis.

scholarly journals Global water availability under high-end climate change: A vulnerability based assessment

2019 ◽  
Vol 175 ◽  
pp. 52-63 ◽  
Author(s):  
A.G. Koutroulis ◽  
L.V. Papadimitriou ◽  
M.G. Grillakis ◽  
I.K. Tsanis ◽  
R. Warren ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
Global Water

scholarly journals The Consequences of Uncertainty: Climate Sensitivity and Economic Sensitivity to the Climate

2018 ◽  
Vol 10 (1) ◽  
pp. 189-205 ◽  
Author(s):  
John Hassler ◽  
Per Krusell ◽  
Conny Olovsson
Keyword(s):  
Climate Change ◽  
Climate Policy ◽  
Climate Sensitivity ◽  
Fossil Fuels ◽  
Carbon Tax ◽  
Green Energy ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Energy Sources ◽  
Negative Impacts

We construct an integrated assessment model with multiple energy sources—two fossil fuels and green energy—and use it to evaluate ranges of plausible estimates for the climate sensitivity, as well as for the sensitivity of the economy to climate change. Rather than focusing explicitly on uncertainty, we look at extreme scenarios defined by the upper and lower limits given in available studies in the literature. We compare optimal policy with laissez faire, and we point out the possible policy errors that could arise. By far the largest policy error arises when the climate policy is overly passive; overly zealous climate policy (i.e., a high carbon tax applied when climate change and its negative impacts on the economy are very limited) does not hurt the economy much as there is considerable substitutability between fossil and nonfossil energy sources.

scholarly journals A global water scarcity assessment under Shared Socio-economic Pathways – Part 2: Water availability and scarcity

2013 ◽  
Vol 17 (7) ◽  
pp. 2393-2413 ◽  
Author(s):  
N. Hanasaki ◽  
S. Fujimori ◽  
T. Yamamoto ◽  
S. Yoshikawa ◽  
Y. Masaki ◽  
...  
Keyword(s):  
Water Use ◽  
Water Availability ◽  
Water Scarcity ◽  
Climate Models ◽  
Water Cycle ◽  
Electricity Production ◽  
Daily Consumption ◽  
Water Abstraction ◽  
Daily Water ◽  
Global Water

Abstract. A global water scarcity assessment for the 21st century was conducted under the latest socio-economic scenario for global change studies, namely Shared Socio-economic Pathways (SSPs). SSPs depict five global situations with substantially different socio-economic conditions. In the accompanying paper, a water use scenario compatible with the SSPs was developed. This scenario considers not only quantitative socio-economic factors such as population and electricity production but also qualitative ones such as the degree of technological change and overall environmental consciousness. In this paper, water availability and water scarcity were assessed using a global hydrological model called H08. H08 simulates both the natural water cycle and major human activities such as water abstraction and reservoir operation. It simulates water availability and use at daily time intervals at a spatial resolution of 0.5° × 0.5°. A series of global hydrological simulations were conducted under the SSPs, taking into account different climate policy options and the results of climate models. Water scarcity was assessed using an index termed the Cumulative Abstraction to Demand ratio, which is expressed as the accumulation of daily water abstraction from a river divided by the daily consumption-based potential water demand. This index can be used to express whether renewable water resources are available from rivers when required. The results suggested that by 2071–2100 the population living under severely water-stressed conditions for SSP1-5 will reach 2588–2793 × 106 (39–42% of total population), 3966–4298 × 106 (46–50%), 5334–5643 × 106 (52–55%), 3427–3786 × 106 (40–45%), 3164–3379 × 106 (46–49%) respectively, if climate policies are not adopted. Even in SSP1 (the scenario with least change in water use and climate) global water scarcity increases considerably, as compared to the present-day. This is mainly due to the growth in population and economic activity in developing countries, and partly due to hydrological changes induced by global warming.

scholarly journals A global water scarcity assessment under shared socio-economic pathways – Part 1: Water use

2012 ◽  
Vol 9 (12) ◽  
pp. 13879-13932 ◽  
Author(s):  
N. Hanasaki ◽  
S. Fujimori ◽  
T. Yamamoto ◽  
S. Yoshikawa ◽  
Y. Masaki ◽  
...  
Keyword(s):  
Water Use ◽  
21St Century ◽  
Water Scarcity ◽  
Climate Modeling ◽  
Water Withdrawal ◽  
Industrial Water ◽  
Domestic Water ◽  
Irrigation Area ◽  
Five Factors ◽  
Global Water

Abstract. A novel global water scarcity assessment for the 21st century is presented in a two-part paper. In this first paper, water use scenarios are presented for the latest global hydrological models. The scenarios are compatible with the socio-economic scenarios of the Shared Socio-economic Pathways (SSPs), which are a part of the latest set of scenarios on global change developed by the integrated assessment, IAV (climate change impact, adaptation, and vulnerability assessment), and climate modeling community. The SSPs depict five global situations based on substantially different socio-economic conditions during the 21st century. Water use scenarios were developed to reflect the key concepts underpinning each situation. Each scenario consists of five factors: irrigation area, crop intensity, irrigation efficiency, industrial water withdrawal, and municipal water withdrawal. The first three factors are used to estimate agricultural water withdrawal. All factors were developed using simple models based on a literature review and analysis of historical records. The factors are grid-based at a spatial resolution of 0.5° × 0.5° and cover the whole 21st century at 5-yr intervals. Each factor displays a wide variation among the different global situations depicted: the irrigation area in 2085 varies between 270 and 450 km2, industrial water between 246 and 1714 km3 yr−1, and domestic water withdrawal between 573 and 1280 km3 yr−1. The water use scenarios can be used for global water scarcity assessments by identifying the regions vulnerable to water scarcity and analyzing the timing and magnitude of scarcity conditions.

scholarly journals Climate impacts on human livelihoods: where uncertainty matters in projections of water availability

2014 ◽  
Vol 5 (1) ◽  
pp. 403-442 ◽  
Author(s):  
T. K. Lissner ◽  
D. E. Reusser ◽  
J. Schewe ◽  
T. Lakes ◽  
J. P. Kropp
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
Water Scarcity ◽  
Climate Change Impacts ◽  
Well Being ◽  
Global Scale ◽  
Climate Impact ◽  
Climate Impacts ◽  
Impact Model ◽  
First Results

Abstract. Climate change will have adverse impacts on many different sectors of society, with manifold consequences for human livelihoods and well-being. However, a systematic method to quantify human well-being and livelihoods across sectors is so far unavailable, making it difficult to determine the extent of such impacts. Climate impact analyses are often limited to individual sectors (e.g. food or water) and employ sector-specific target-measures, while systematic linkages to general livelihood conditions remain unexplored. Further, recent multi-model assessments have shown that uncertainties in projections of climate impacts deriving from climate and impact models as well as greenhouse gas scenarios are substantial, posing an additional challenge in linking climate impacts with livelihood conditions. This article first presents a methodology to consistently measure Adequate Human livelihood conditions for wEll-being And Development (AHEAD). Based on a transdisciplinary sample of influential concepts addressing human well-being, the approach measures the adequacy of conditions of 16 elements. We implement the method at global scale, using results from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) to show how changes in water availability affect the fulfilment of AHEAD at national resolution. In addition, AHEAD allows identifying and differentiating uncertainty of climate and impact model projections. We show how the approach can help to put the substantial inter-model spread into the context of country-specific livelihood conditions by differentiating where the uncertainty about water scarcity is relevant with regard to livelihood conditions – and where it is not. The results indicate that in many countries today, livelihood conditions are compromised by water scarcity. However, more often, AHEAD fulfilment is limited through other elements. Moreover, the analysis shows that for 44 out of 111 countries, the water-specific uncertainty ranges are outside relevant thresholds for AHEAD, and therefore do not contribute to the overall uncertainty about climate change impacts on livelihoods. The AHEAD method presented here, together with first results, forms an important step towards making scientific results more applicable for policy-decisions.

Sign in / Sign up

Export Citation Format

Share Document