UN World Water Development Report 2018 (Part 1)

The UN World Water Development Report 2018 focused on the theme:

Nature-Based Solutions for Water - Working with nature to improve the management of water resources, achieve water security for all, and contribute to core aspects of sustainable development

Main Facts and Figures from WWDR 2018

Water Demand

·      Contemporary global water demand has been estimated at about 4,600 km3 per year and projected to increase by 20–30% to between 5,500 and 6,000 cu km per year by 2050.

·      Water use increases at the global level, as a function of population growth, economic development and changing consumption patterns, among other factors.

·      Over the period 2017–2050, the world population is expected to increase from 7.7 billion to between 9.4
and 10.2 billion, with two thirds of the population living in cities. More than half of this anticipated growth is expected to occur in Africa (+1.3 billion), with Asia (+0.75 billion) expected to be the second largest contributor to future population growth.

·      Global water use has increased by a factor of six over the past 100 years and continues to grow steadily at a rate of about 1% per year.

·      Domestic water use, which roughly accounts for 10% of global water withdrawals, is expected to increase significantly over the 2010–2050 period in nearly all regions of the world.  

·      Groundwater use globally, mainly for agriculture, amounts to 800 cu km per year in the 2010s, with India, the US, China, Iran and Pakistan (in descending order) accounting for 67% of total abstractions worldwide.

·      Global demands for agricultural and energy production (mainly food and electricity), both of which are water-intensive, are expected to increase by roughly 60% and 80%, respectively by 2025.

·      Meeting the estimated 60% increase in food demand will require the expansion of arable land under business-as-usual. Under prevailing management practices, intensification of production involves increased mechanical disturbance of soil and inputs
of agrochemicals, energy and water. These drivers associated with food systems account for 70% of
the predicted loss of terrestrial biodiversity by 2050. However, these impacts, including requirements for more land and water, can largely be avoided if further intensification of production
is based on ecological intensification that involves improving ecosystem services to reduce external inputs.

Growing Water Scarcity

·      Many countries are already undergoing pervasive water scarcity conditions and will likely have to cope with lower surface water resources availability in the 2050s.

·      Throughout the early-mid 2010s, about 1.9 billion people (27% of the global population) lived in potential severely water-scarce areas. If monthly variability is taken into account, 3.6 billion people worldwide (nearly half the global population) are already living in potential water- scarce areas at least one month per year and this could increase to some 4.8–5.7 billion in 2050. About 73% of the affected people live in Asia (69% by 2050).

·      Water withdrawals for irrigation have been identified as the primary driver of groundwater depletion worldwide. For the 2050s, a large surge in groundwater abstractions amounting to 1,100 cu km per year has been predicted, corresponding to a 39% increase over current levels.

·      A third of the world’s biggest groundwater systems
are already in distress. The above-mentioned groundwater trends also assume increasing withdrawals from non-renewable (fossil) groundwater – indisputably an unsustainable path.

·      The importance of current water availability challenges can only be fully understood by comparing water withdrawal to their maximum sustainable levels. At about 4,600 cu km per year, current global withdrawals are already near maximum sustainable levels and, as noted in previous World Water Development Reports, global figures mask more severe challenges at regional and local scales.

Water Quality

·      Since the 1990s, water pollution has worsened in almost all rivers in Africa, Asia and Latin America. The deterioration of water quality is expected to escalate over the next decades and this will increase threats to human health, the environment and sustainable development.

·      An estimated 80% of all industrial and municipal wastewater is released to the environment without any prior treatment, resulting in a growing deterioration of overall water quality with detrimental impacts on human health and ecosystems.