Water sources are vulnerable, too often ill-managed and inequitably distributed between the rich and the poor. If nothing is done to reduce the emissions of carbon dioxide and other greenhouse gases which are believed to lead to global warming, scientists warn that global temperatures might increase by 1 to 3.5 degrees centigrade by the year 2100. Scientists believe that the climate changes would increase the number of deaths and illnesses due to infectious diseases. For instance, mosquitos may extend their range to new geographical areas, leading to more cases of malaria. However, drought is the largest cause of death because it often leads to famine.
Floods affect more regions and more people than any other phenomenon.
The consequences of flooding, especially in poor communities, can be horrific. This was seen in the disastrous floods that occurred in the aftermath of the powerful cyclones that struck Madagascar and Mozambique in February 2000. Many people died, hundreds of thousands of people were made homeless, epidemics of malaria and cholera broke out, rich farmland was rendered useless and economic development received a severe setback. The after-effects of a major flood usually linger on for many years. The breakdown of water and sanitation services increases vulnerability to waterborne diseases.