High natural nitric oxide emissions from lakes on Tibetan Plateau under rapid warming

Abstract Nitrogen oxides affect health and climate. Their emissions from inland waters such as lakes are generally considered negligible and are absent in air quality and climate models. Here we find unexpected high emissions from remote lakes on the Tibetan Plateau based on satellite observations and emission inversion. The total emissions from 135 lakes larger than 50 km2 reach 1.9 Ton N h− 1, comparable to individual megacities worldwide. The emissions per unit area exceed those from crop fields. This is the first report of strong natural emissions from inland waters. The emissions are likely from anammox-dominated microbial processes under low-oxygen, low-organic, alkaline and saline conditions. They are associated with substantial warming and glacial and permafrost melting on the plateau, constituting a previously unknown feedback between climate, lake ecology and nitrogen emissions.