The study by Bastviken et al. (2011) highlights the significant role of freshwater ecosystems in the global carbon cycle, particularly in methane (CH4) emissions. The authors compiled data from 474 freshwater ecosystems and estimated that these ecosystems emit at least 103 Tg of CH4 annually, equivalent to 0.65 Pg C as CO2 equivalents, which offsets 25% of the estimated land carbon sink. This suggests that the continental GHG sink may be overestimated, and freshwaters should be recognized as important contributors to the global carbon cycle. The study also notes that ebullition and plant-mediated emissions, which are poorly represented in current data, are likely underestimates and could lead to higher future estimates of CH4 emissions. Overall, the findings indicate that freshwaters play a crucial role in the global land GHG sink and require further attention in future revisions of net continental GHG fluxes.The study by Bastviken et al. (2011) highlights the significant role of freshwater ecosystems in the global carbon cycle, particularly in methane (CH4) emissions. The authors compiled data from 474 freshwater ecosystems and estimated that these ecosystems emit at least 103 Tg of CH4 annually, equivalent to 0.65 Pg C as CO2 equivalents, which offsets 25% of the estimated land carbon sink. This suggests that the continental GHG sink may be overestimated, and freshwaters should be recognized as important contributors to the global carbon cycle. The study also notes that ebullition and plant-mediated emissions, which are poorly represented in current data, are likely underestimates and could lead to higher future estimates of CH4 emissions. Overall, the findings indicate that freshwaters play a crucial role in the global land GHG sink and require further attention in future revisions of net continental GHG fluxes.