The impact of extreme weather events on water quality: international evidence

Water resources are an important part of the ecosystem. The nexus of extreme weather events and water quality is of great significance in the climate change economics theory and related literature. This research thus investigates the impact of extreme weather events on water quality by using unbalanced panel data covering 62 countries from 1991 to 2018 and finds that extreme weather may strongly hurt water quality, which not only is impactful in the current year but also lasts over the next 10 years. We further show that floods have a greater negative impact on water quality than droughts. In addition, the significant impact on water quality is manifested in non-high-income countries and in countries with low technology innovation related to water resources, but not in high-income countries nor in countries with high water innovation. Overall, the findings merit particular attention from policy makers.