Review of Week 5 of Water Supply and Sanitation Policy in Developing Countries Part 1: Understanding Complex Problems (University of Manchester, Coursera)
Water supply and sanitation interventions can play a large role in improving health outcomes, although causality is not always clear and the extent of improvement can vary. In fact, Prof Whittington gave a scenario where piped water implemented in a slum without drainage or sanitation could create other pathways to transmit disease. (See my favourite F-diagram!) Estimating the economic value of health benefits due to water supply and sanitation interventions seems like a futile exercise, because the parameters are so uncertain.
Climate change will have multi-faceted and complex effects on water supply and sanitation. Causal effects include rainfall, temperature, sea level rise and extreme events, and impacts can be related to food and water-borne infections, vector-borne diseases, under-nutrition and heat. But the effects are uncertain. For example, with disease, different pathogens will react to climate change in different ways, which means the overall effect is unclear. Households and countries will have to adapt accordingly.