Variations in GHG fluxes in small- and medium-sized water bodies in different climate zones.

Small-medium-sized water bodies (S&M-WBs) are important ecosystems also linked to global GHG emissions, although their contribution to global warming is often underestimated. Through a meta-analysis, this study integrated data from multiple studies, and comprehensively assessed GHG emissions from S&M-WBs. Results indicated that GHG emissions from S&M-WBs showed an overall increase over the past 20 years. Changes in CO2 emissions were not significant globally. In contrast, CH4 and N2O showed notable differences across various climate zones. These differences were closely related to the distinct mechanisms and conditions under which each gas is produced. Broader-scale drivers, particularly climatic changes and anthropogenic activities, shape the overall GHG emission patterns across climate zones. This study reveals the complexity of GHG production and emissions from S&M-WBs, as well as the uncertainties in their responses to climate change and anthropogenic pressures. It also cautions against oversimplifying the relationship between GHG fluxes from S&M-WBs and climate change in freshwater ecosystem research. Instead, analyses should be refined based on GHGs species and geographic region to ensure that global GHG production and emission models accurately capture differences in gas-specific behaviors, regional variations, and underlying mechanisms.