Carbon gas to and from inland water: Support for a global observation networas to and from inland water: Support for a global observation networ

Research on carbon gas flux to and from inland waters has increased over the past two decades, driven mainly by the need to understand (1) the global carbon budget in regard to stabilizing earth’s climate, and (2) how aquatic ecosystems and the services they provide change in response to anthropogenic pressures like climate and land use change. This paper reviews carbon flux research in support of a proposed global carbon monitoring network to inform public policy. It begins with an overview of the physical–chemical processes and quantification tools for carbon gas flux, and then highlights their application to streams, rivers, lakes, reservoirs and estuaries. Research outcomes to date point to spatiotemporal coverage gaps owing to the complexity of the aquatic ecosystems and land–water interactions, suggesting that long-term monitoring is needed to better understand their signals in response to changes in climate and land management. While better monitoring of gas flux is an important piece of the global carbon budget resolution problem, new information will need to be developed and integrated to adequately inform carbon policymaking. This information can stem from developments in large-scale carbon status and flux assessment tools, such as via remote sensing platforms, and from improved integrated watershed-to-water body modeling efforts.