Coastal waterways can be significant sources of the potent greenhouse gas nitrous oxide (N 2 O) due to nitrogen inputs and eutrophication. Here, we quantify groundwater derived N 2 O inputs and atmospheric emissions within a modified urban embayment (Sydney Harbour, Australia). Overall, we found low N 2 O saturation (91–171%) and air–water fluxes (−2.2 to 24.6 μ mol m −2 d −1 ). Concentrations were highest in upstream brackish...

Urban and agricultural development of coastal catchments is known to increase dissolved nitrogen inputs into estuaries; however, much less is known about how land use influences the production of the powerful greenhouse gas nitrous oxide (N 2 O). Here, we assess dissolved N 2 O dynamics in four nearby estuaries across a regional land use gradient and summarize the literature to put the observations into global perspective. Dur...