異常気象
Climate change can have negative impacts on existing sanitation services in several ways: damage and loss of services from floods and reduced carrying capacity of waters receiving wastewater. The sanitation sector is already affected in many different ways by "weather and climate-related phenomena such as variability, seasonality and extreme weather events". Extreme weather events, such as floods and droughts, are increasing in frequency and intensity due to climate change. They affect the operation of water supply, storm drainage and sewerage infrastructure, and wastewater treatment plants. A publication by WHO provides guidance on how adaptation policies should consider these risks from extreme weather events.