The future of global water stress: An integrated assessment

Abstract

We assess the ability of global water systems, resolved at 282 assessment subregions (ASRs), to the meet water requirements under integrated projections of socioeconomic growth and climate change. We employ a water resource system (WRS) component embedded within the Massachusetts Institute of Technology Integrated Global System Model (IGSM) framework in a suite of simulations that consider a range of climate policies and regional hydroclimate changes out to 2050. For many developing nations, water demand increases due to population growth and economic activity have a much stronger effect on water stress than climate change. By 2050, economic growth and population change alone can lead to an additional 1.8 billion people living under at least moderate water stress, with 80% of these located in developing countries. Uncertain regional climate change can play a secondary role to either exacerbate or dampen the increase in water stress. The strongest climate impacts on water stress are observed in Africa, but strong impacts also occur over Europe, Southeast Asia, and North America. The combined effects of socioeconomic growth and uncertain climate change lead to a 1.0-1.3 billion increase of the world's 2050 projected population living with overly exploited water conditions-where total potential water requirements will consistently exceed surface water supply. This would imply that adaptive measures would be taken to meet these surface water shortfalls and include: water-use efficiency, reduced and/or redirected consumption, recurrent periods of water emergencies or curtailments, groundwater depletion, additional interbasin transfers, and overdraw from flow intended to maintain environmental requirements.

Assessment of methods for seasonal streamflow forecasting in the Upper Indus Basin of Pakistan

“…Other studies confirm Pakistan's relatively high levels of exploitation of river flows and groundwater, associated water stress and resultant exposure to climate change (Döll et al, 2009;Wada et al, 2011;Schlosser et al, 2014;Kirby et al, 2017). Given 5 the high demands on the main water source, the Indus River, its year to year flow variability has a significant impact on security of supply in the Indus Basin Irrigation System (IBIS) of Pakistan.…”

Changing Characteristics of the Water Consumption Structure in Nanjing City, Southern China

“…The shortage of water resources due to rapid economic development, population growth, urbanization and climate change have hindered future economic and social development in many countries [1][2][3][4][5][6]. Usually, agricultural water (AW) consumption accounts for the largest proportion of total water consumption, but with population growth and economic development, industrial water (IW) and domestic water (DW) consumption have been growing rapidly in recent decades [7][8][9].…”

“…As shown in Figure 3, the total water consumption increased by 575 million m 3 in the last 22 years. In 2011, it reached a maximum of 4.562 billion m 3 , but there has been a downward trend in the last three years. Among the different sectors, the most remarkable decrease was AW consumption, whereas there were huge increases in both IW and DW consumption.…”

“…Among the different sectors, the most remarkable decrease was AW consumption, whereas there were huge increases in both IW and DW consumption. AW consumption decreased by 335 million m 3 between 1993 and 2014. The proportion of AW consumption relative to the total water consumption decreased from 0.51 in 1993 to 0.36 in 2014.…”

“…In order to address severe environmental and ecological problems that have emerged in recent years, EW consumption measures were initiated in 2005, which mainly comprise water consumption by the renewed inner urban landscape rivers and the outer rivers. EW consumption increased from 20 million m 3 …”