An Outsized Contribution of Rivers to Carbon Emissions From Interconnected Urban River‐Lake Networks Within Plains

Abstract Urban aquatic ecosystems in plains are often subject to extensive anthropogenic pollutant inputs and have prolonged times for pollutant degradation, potentially leading to diverse carbon emission patterns. This study explored carbon emission patterns and underlying mechanisms in Ge Lake and its tributaries, located in an urban area within a plain in China. The results revealed that carbon emissions from rivers were significantly higher than those from the downstream lake. Spatial interpolation analysis further revealed that CO 2 ‐eq emissions from a 1‐km 2 river area can be equivalent to those from an area as large as 86‐km 2 of the downstream lake. Rivers are the gateway for the entry of organic compounds, often carrying substances that are readily biodegradable. As the river water moves slowly, these compounds accumulate and undergo degradation in rivers before they reach downstream lakes. The findings may benefit the estimates of carbon emissions in these regions with greater precision.