6.2 The Anthropocene and the Global Water Crisis
55
(habitat fragmentation, invasive species, etc.) accelerating climate change may trigger the sixth great extinction event on planet Earth (Zalasiewicz et al. 2010).
6.2.2 The Impacts of the Anthropocene on Freshwater
Resources: The Global Water Crisis
Water is one of the key environmental media through which the above negative
changes are manifested. As Rockström et al. conclude in their flagship publication
on planetary boundaries:
[t]he global freshwater cycle has entered the Anthropocene because humans are now the
dominant driving force altering global scale river flow and the spatial patterns and seasonal
timing of vapour flows (Rockström et al. 2009).
The UN’s regular publications on water security, the World Water Development
Reports, identify the ever increasing global demand as the main stressor on the
availability and quality of freshwater resources. Expanding economies have been
demanding more water for more food production, fibre and energy. The emergence
of the global middle class has prompted an unsustainable increase in water use, especially in regions already characterised by water stress. Over the past decades the rate
of demand for water has doubled the rate of population growth. Demand for water is
expected to further increase in all sectors of production. By 2030, the world is projected to face a 40% global water deficit (i.e. demand for freshwater will outreach
supply by 40%), if current trajectories remain unchanged. The ensuing urbanisation
gives rise to special water challenges. Already, more than 50% of the world’s population lives in cities where 30% of all city-dwellers reside in slums without proper
access to water and sanitation. 40% of all urban expansion in developing countries
is made up by slums (WWAP 2015).
Broken down by sector, the impacts of energy production and agriculture on water
clearly stand out. Fossil, nuclear, hydro-power generation and mining are major users
of water. Energy production accounts for 15% of water consumption today, but it is
expected to rise to 20% by 2035. Globally, however, it is agriculture that is already
the biggest water consumer, singlehandedly responsible for 70% of all freshwater
withdrawals. Unless major improvements take place in water use efficiency, the water
footprint of agriculture is likely to further increase due to population pressure and
the extension of irrigation necessitated by declining river runoffs (WWAP 2015).
The regional and global water of impact of agriculture is also strongly influenced by
the import or export of water in raw or processed foods. While such “virtual water”
usually fails to feature in the water balance of either the exporting or the importing
country, it does have a significant overall effect on national water supply and demand.
Given the increased competition for water among human and economic needs
water quality and ecosystem integrity is often overlooked. In most parts of the developing world population and economic growth leads to uncontrolled surface and
groundwater pollution. Groundwater, the most widely used source of drinking water
55
(habitat fragmentation, invasive species, etc.) accelerating climate change may trigger the sixth great extinction event on planet Earth (Zalasiewicz et al. 2010).
6.2.2 The Impacts of the Anthropocene on Freshwater
Resources: The Global Water Crisis
Water is one of the key environmental media through which the above negative
changes are manifested. As Rockström et al. conclude in their flagship publication
on planetary boundaries:
[t]he global freshwater cycle has entered the Anthropocene because humans are now the
dominant driving force altering global scale river flow and the spatial patterns and seasonal
timing of vapour flows (Rockström et al. 2009).
The UN’s regular publications on water security, the World Water Development
Reports, identify the ever increasing global demand as the main stressor on the
availability and quality of freshwater resources. Expanding economies have been
demanding more water for more food production, fibre and energy. The emergence
of the global middle class has prompted an unsustainable increase in water use, especially in regions already characterised by water stress. Over the past decades the rate
of demand for water has doubled the rate of population growth. Demand for water is
expected to further increase in all sectors of production. By 2030, the world is projected to face a 40% global water deficit (i.e. demand for freshwater will outreach
supply by 40%), if current trajectories remain unchanged. The ensuing urbanisation
gives rise to special water challenges. Already, more than 50% of the world’s population lives in cities where 30% of all city-dwellers reside in slums without proper
access to water and sanitation. 40% of all urban expansion in developing countries
is made up by slums (WWAP 2015).
Broken down by sector, the impacts of energy production and agriculture on water
clearly stand out. Fossil, nuclear, hydro-power generation and mining are major users
of water. Energy production accounts for 15% of water consumption today, but it is
expected to rise to 20% by 2035. Globally, however, it is agriculture that is already
the biggest water consumer, singlehandedly responsible for 70% of all freshwater
withdrawals. Unless major improvements take place in water use efficiency, the water
footprint of agriculture is likely to further increase due to population pressure and
the extension of irrigation necessitated by declining river runoffs (WWAP 2015).
The regional and global water of impact of agriculture is also strongly influenced by
the import or export of water in raw or processed foods. While such “virtual water”
usually fails to feature in the water balance of either the exporting or the importing
country, it does have a significant overall effect on national water supply and demand.
Given the increased competition for water among human and economic needs
water quality and ecosystem integrity is often overlooked. In most parts of the developing world population and economic growth leads to uncontrolled surface and
groundwater pollution. Groundwater, the most widely used source of drinking water