More than 5 billion people could suffer water shortages by 2050 due to climate change, increased demand and polluted supplies, according to a UN report on the state of the world’s water. The comprehensive annual study, World Water Development Report, warns of conflict and civilizational threats unless actions are taken to reduce the stress on rivers, lakes, aquifers, wetlands and reservoirs.
Humans use about 4,600 cubic km of water every year, of which 70% goes to agriculture, 20% to industry and 10% to households, says the report, which was launched at the start of the triennial World Water Forum. Global demand has increased sixfold over the past 100 years and continues to grow at the rate of 1% each year.
This is already creating strains that will grow by 2050, when the world population is forecast to reach between 9.4 billion and 10.2 billion (up from 7.7 billion today), with two in every three people living in cities.
By 2050, the report predicts, between 4.8 billion and 5.7 billion people will live in areas that are water-scarce for at least one month each year, up from 3.6 billion today, while the number of people at risk of floods will increase to 1.6 billion, from 1.2 billion.
Demand for water is projected to rise fastest in developing countries. Meanwhile, climate change will put an added stress on supplies because it will make wet regions wetter and dry regions drier. The report says positive change is possible, particularly in the key agricultural sector, but only if there is a move towards nature-based solutions that rely more on soil and trees than steel and concrete.