Drivers of CO2 and CH4 fluxes from shallow lakes and prediction based on climate factors under global warming.

Shallow lakes are recognized as significant sources of greenhouse gas (GHG) emissions, yet long-term measurements and predictions of GHG fluxes from these ecosystems remain limited. Here, we systematically investigated the temporal dynamics of GHG fluxes and the underlying drivers in a shallow lake in Zhejiang Province, Yangtze River Delta, China, using the static floating chamber method. The annual average fluxes were positive, implying the lake is a substantial carbon source, with CO2 fluxes of 10.83 ± 11.25 mmol/(m2·day) and CH4 fluxes of 1.64 ± 0.96 mmol/(m2·day). Principal component analysis identified air temperature and pressure as key meteorological drivers influencing water quality and GHG fluxes. Combining multiple linear regression models, we predict GHG fluxes from water bodies in China under low, medium and high carbon emissions scenarios for the years 2030 and 2060, providing important insights for predicting greenhouse gas fluxes from water bodies during China's carbon neutrality period. Our predictions suggest that water bodies in the Tibetan Plateau will become an intense GHG source, exacerbated by fragile ecosystems and abundant water resources. Additionally, CH4 fluxes from southern China's water bodies are expected to rise notably with higher emissions scenario, likely driven by rapid warming and intensified anaerobic fermentation in rice paddies. These findings highlight the significant potentials for GHG emissions from water bodies during China's carbon neutrality period and underscore the importance of water quality management to mitigate these emissions.