Overall, uncertainty as to the quantity of carbon fluxes within fresh- water ecosystems and between terrestrial and freshwater systems, and subsequent emissions to the atmosphere remains very high  . Projections of carbon fluxes are, for example, challenged by the com- plex interaction between rising water temperatures, loss of ice, changes in hydrology, ecosystem productivity, increased extreme events and variation in terrestrial-matter transport. While we are still short of empirical data, particularly in the Tropics , im- provements in sensor technology  and the use of statistically robust survey designs  have improved the accuracy of measurements of GHG emissions in freshwater ecosystems. Global networks such as the Global Lakes Ecological Observatory Network  increasingly allow a global view of carbon fluxes, thereby improving estimates of the contribution of freshwater ecosystems to global GHG emissions to the atmosphere.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report