Abstract
Issues causing increased water stress and availability throughout the world are complex. The importance of supply-side issues arising from increasing urbanization, causing localized levels of water stress, is described. Further, while the world population has doubled over the last 50 years, water use has tripled. Water use rates have increased (from 400km3 per year per billion people in 1965, to the current level of 600km3 per year per billion people in 2015), as a result of population growth with its associated food and energy implications, and dietary shifts of populations.
Water demands in 2025 are projected to be 1500km3 per year, or 60% more than volumes in 2015. The findings in a case study in the Zambezi River basin indicate that while climate change is projected as 25% of the projected impact to future water security issues, 75% of water security issues are attributable to population increases (and its related food, energy, and changing dietary habits) and hence, population increases represent a greater threat to water security.
References
Postel SL. Water and World Population Growth. American Water Works Assn Journal Arr 2000; 92: 4.
Pickens T. Boone. www.businessweek.com/stories/2008-06- 11/there-will-be-water) 2008.
www.unwater.org/topics/water-food and energy-nexus/eng/.
baen.tamu.edu/2015/08/water-energy food symposium.set. nov 19-in-austin/.
flores.unu.edu/about-us/th-nexus/approach/.
www.fao.org/nr/water/docs/FAO nexus concept.pdf.
www.newsecuritybest.org/2014/05/climate.threats.military.lea ders/population.growth.natura.resources.key-factors/.
Vörösmarty CJ, Green P, Salisbury J and Lammers R. Global Water Resources: Vulnerability from Climate Change and Population Growth. Science 2007; 289: 284-288. http://dx.doi.org/10.1126/science.289.5477.284
Falkenmark M. Rapid population growth and water scarcity: The predicament of tomorrow's Africa. Population and Development Review 1990; 16: 81-94. http://dx.doi.org/10.2307/2808065
World Wildlife Fund. Big Cities, Big Water, Big Challenges: www.wwf.se/source.php/1390895/, accessed January 25, 2016.
IPCC 2006. Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. by Griggs, D and Noguer, M. http://dx.doi.org/10.1256/004316502320517344
IPCC. Fourth Assessment Report Climate Change 2007. http://www.ipcc.ch/publications_and_data/ar4/syr/en/contents.html.
www.everylittledrop.com.au (accessed May 9, 2016).
Mongabay (www.mongabay.com) accessed August 26, 2015.
Wikipedia, (www.wikipediaMegacity), accessed August 26, 2015.
UNEP. 2008. “Water Withdrawal and consumption, The Big Gap”, www.unep.orgdeva/vitalwater/article42.html.
Shiklomanov IA. State Hydrological Institute (SHI, St. Petersburg) and United Nations Educational Scientific and Cultural Organization (UNESCO, Paris), 1999.
(www.populationpyramid.net (accessed May 2016)).
United Nations. 2007. “The World of Six Billion (October 1999) and World Population Prospects: The 2006 Revision (February 2007), Department of Social and Economic Affairs, Population Division, New York.
World Wildlife Organization, http://www.worldwildlife. org/threats/water-scarcity, accessed August 26, 2015.
Shah T. The Groundwater Economy of South Asia: As Assessment of Size, Significance and Socio-ecological Impacts. In Giordano, M., and Villholth, K.G. (Eds.), The Agricultural Groundwater Revolution: Opportunities and Threats to Development (7-36). Wallingford, UK: CAB International 2007.
Schwarz F and Ibaraki M. Groundwater: A Resource in Decline, Geoscience World 2011; 7(3): 175-179. http://dx.doi.org/10.2113/gselements.7.3.175
Arnell NW. Climate change and global water resources. Global Environmental Change 1999; 9(Supplement 1): S31-S49. http://dx.doi.org/10.1016/S0959-3780(99)00017-5
Christensen NS, Wood AW, Voisin N, Lettenmaier DP and Palmer RN. The effects of climate change on the hydrology and water resources of the Colorado River Basin. Climatic change 2004; 62(1-3): 337-363. http://dx.doi.org/10.1023/B:CLIM.0000013684.13621.1f
Haddeland I, Heinke J, Biemans H and Eisner S. Global Water Resources Affected by Human Interventions and Climate Change. Proceedings of the National Academy of Sciences 2014; 111(9): 3251-3256. http://dx.doi.org/10.1073/pnas.1222475110
(www.theguardian.com (accessed May 9, 2016)).
Economist, http://www.economist.com/world/international /displayStory.cfm?story_id=13447271, accessed February 12, 2015.
Technology http://www.acdi-cida.gc.ca/INET/IMAGES. NSF/vLUImages/youthzone/$file/pie-e.gif, accessed 2015.
Our Finite World, https://Ourfiniteworld.com/2012/03/12/world energyconsumption, accessed on August 15, 2015.
US EPA, www.epa.gov/region9/waterinfrastructure/ waterenergy.html, accessed August 30, 215.
deJong A, McBean E and Gharabaghi B. Projected Climate Conditions to 2100 for Regina, Saskatchewan. Canadian Journal of Civil Engineering 2010; 37: 1-14. http://dx.doi.org/10.1139/L10-061
Zhang C and McBean E. Adaptation Investigations to Response to Climate Change Projections in Gansu Province, Northern China. Water Resources Management 2014; 28: 1531-1544. http://dx.doi.org/10.1007/s11269-014-0554-x
Zhang C, McBean E, Ali I and Huang J. (in review) Projected Water Stress Due to Climate Change and Population Growth for the Zambezi River Basin. Hydrologic Science 2016.
UN DESA, 2013. World Population Prospects: The 2012 Revision.
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