Impact of water quality drivers and lake eutrophication on greenhouse gas emission rate: A critical analysis

Abstract

In recent decades, anthropogenic disturbance and rising climate change exposed global lakes, in particular shallow lakes,  to an increased risk of eutrophication. Thus received global attention due to their high greenhouse gas (GHG) emissions contributing to global warming. The role of the lake trophic state index (TSI) and water quality parameters such as chlorophyll-a (Chl-a), pH, total organic carbon (TOC), and total phosphorus (TP) on GHG emissions are still poorly estimated and a hot topic of global discussion to understand the key sources and drivers of GHG emissions. In this study, GHG and lake eutrophication datasets of 146 lakes in China have been collected from the scientific literature and analyzed statistically to determine the influence of lake eutrophication on GHG emissions. The statistical analysis reveals that Chl-a (R2 > 0.90) and TOC (R2 > 0.65) are the key factors of eutrophication and dominate carbon intensity dynamics in the Chinese lakes. Our finding further suggests that CH4 contributes largely to regional carbon budgets compared to CO2 and N2O. Proactive management of lake catchment not only reduces the potential GHG emissions but also helps in lake restorations.