Kathmandu. A new study has shown that oxygen levels in rivers worldwide are continuously decreasing due to climate change, creating serious risks for fresh water. This study has been published in the scientific journal 'Science Advances'.The research was led by researchers from the Nanjing Institute of Geography and Limnology under the Chinese Academy of Sciences. The research team analyzed data from approximately 40 years, from 1985 to 2023. Advanced computer-based analysis methods were used to measure oxygen levels in over 21,000 river segments worldwide.According to the study, oxygen levels in rivers are decreasing at an average rate of 0.045 milligrams...