Climate change alters the hydrological cycle by increasing the frequency of extreme weather events such as excess precipitation, storm surges, floods and droughts . Water-borne diseases, such as diarrhoea, leptospirosis and typhoid fever, can increase in incidence following heavy rainfall, tropical cyclones and flooding events  . Droughts can cause increased concentrations of pathogens, which overwhelm water-treatment plants and contaminate surface water. A positive association between ambient temperature and bacterial diarrhoea has been reported, compared with a negative association with viral diarrhoea .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report