Over 80 per cent of wastewater worldwide is not collected or treated, and urban settlements are the main source of pollution.
827.6 million people live in slums, often lacking adequate drinking water and sanitation services. Slums are projected to grow by 27 million people per year. In Africa and Asia, the urban population will double between 2000 and 2030.
Today, one in two people on the planet live in a city and every second, the urban population grows by 2 people. 93% of the urbanization occurs in poor or developing countries, and nearly 40% of the world's urban expansion is growing slums.
The world population is predicted to grow from 6.9 billion in 2010 to 8.3 billion in 2030 and to 9.1 billion in 2050. At the same time, urban population is projected to increase by 2.9 billion, to a total of 6.3 billion in 2050.
Between 1990 and 2000, in several developing countries, natural disasters caused damage representing between 2% and 15% of their annual GDP.
Between 1991 and 2000 over 665 000 people died in 2 557 natural disasters of which 90% were water related. According to the UN Global Assessment Report, since 1900 more than 11 million people have died as a consequence of drought and more than 2 billion have been affected by drought, more than any other physical hazard. The frequency and intensity of such hazards is generally rising.
The Pacific’s small island developing states (SIDS) in particular are vulnerable to environmental natural hazards, such as tropical cyclones, typhoons and earthquakes turning into disasters. Climate change will further exacerbate the vulnerability of SIDS with anticipated sea-level rise and the risk of storm surge and beach erosion. One tropical cyclone can negate years of development efforts.
A study of 141 countries found that more women than men die from natural hazards, and that this disparity is linked most strongly to women’s unequal socio-economic status.