Anthropogenic land use substantially increases riverine CO2 emissions

•The mean pCO2 was 1474 ± 1614 µatm in the Yue River draining to the Yangtze.•Anthropogenic land use had major seasonal influence on riverine pCO2.•Annual CO2 emissions were 1.6-2.8 times greater than river dissolved carbon discharge.•Urban land use and nutrient concentrations were used to predict riverine pCO2.