How Humans (Can) Impact Global Water Resources

Our blue planet seems to be covered with water, but fresh water is a surprisingly precious asset.

A mere 0.02% of the global total of the Earth's surface water is both fresh (i.e. not saline) and relatively accessible (i.e. not trapped in ice sheets, glaciers, and as deep groundwater) (Robinson and Ward 2017).

Generally speaking, water resources are under immense pressure due to demand generated by rising population rates (especially in urban areas), mining operations, and industrial development (de Amorim et al 2018; Boelee et al 2019).

As the world population continues to grow, so the heightened demand for food engenders the expansion and intensification of food production. Agricultural waste such as manure, nutrients, and chemicals, and agricultural practices such as crop irrigation, are the leading actors both in depleting and polluting water resources (Evans et al 2019).

On a long-term basis, the most important and persistent anthropogenic sources of water pollution originate from inter alia mining activities and hazardous waste sites, which generate significant levels of waste deposits and toxic chemicals in the soil and in runoff (Schwarzenbach et al 2010).

Social inequities are integral in determining access to safe water supply and adequate sanitation, thereby leading to human behaviours which (further) affect the availability of clean water resources.

Lack of access to sanitary toilets, as well as inadequate wastewater management and treatment infrastructure, contribute to the circulation of pathogens and organic loads through water (Boelee et al 2019). The metabolization or improper disposal of pharmaceuticals add to the contamination of precious water supplies (Schwarzenbach et al 2010).

Water shortages can be attributed at least in part to anthropogenic climate change and its effects on extreme weather events and hydrological processes (de Amorim et al 2018). As waters infiltrate inland due to rising sea levels, this increases the salt load in inland waters, reducing freshwater quality and supply (Schwarzenbach et al 2010).

For the sake of intra- and inter-generational equity, it could be argued, at least in the more affluent segments of the world population, that there are good reasons to reduce water usage, to limit the amount of pollutants emitted into precious water supplies, and to make deliberate consumer, charitable, and investment choices.

References:-

• Boelee, E., G. Geerling, B. van der Zaan, A. Blauw and A.D. Vethaak. (2019). ‘Water and health: from environmental pressures to integrated responses’, Acta Tropica 193 2019, pp.217–26.

• de Amorim, W.S., I.B. Valduga, J.M.P. Ribeiro, V.G. Williamson, G.E. Krauser, M.K. Magtoto and J. Baltazar Salgueirinho Osório de Andrade Guerra. (2018). ‘The nexus between water, energy, and food in the context of the global risks: an analysis of the interactions between food, water, and energy security’, Environmental Impact Assessment Review 72 2018, pp.1–11.

• Evans, A.E., J. Mateo-Sagasta, M. Qadir, E. Boelee and A. Ippolito. (2019). ‘Agricultural water pollution: key knowledge gaps and research needs’, Current Opinion in Environmental Sustainability 36 2019, pp.20–7.

• Robinson, M. and R.C. Ward. (2017). 'Hydrology principles and processes'. (London: IWA Publishing, 2017) [ISBN 9781780407296]

• Schwarzenbach, R.P., T. Egli, T.B. Hofstetter, U. Von Gunten and B. Wehrli. (2010). ‘Global water pollution and human health’, Annual Review of Environment and Resources 35 2010, pp.109–36.