Many inland waters are drying up due to global change, exposing sediments to the atmosphere. Data on CO2 emissions from these sediments are scarce, hindering global emission estimates and understanding of drivers. This study presents a global survey of 196 dry inland waters across diverse ecosystems and climate zones. CO2 emissions showed consistent drivers across ecosystems and climate zones, with local characteristics explaining much of the variability. Accounting for these emissions increases global estimates of carbon emissions from inland waters by 6% (-0.12 Pg C y-1). Emissions from dry inland waters represent a significant and likely increasing component of the inland waters carbon cycle.

P.S. Keller, N. Catalán, D. von Schiller, H.-P. Grossart, M. Koschorreck, B. Obrador, M. A. Frassl, N. Karakaya, N. Barros, J. A. Howitt, C. Mendoza-Lera, A. Pastor, G. Flaim, R. Aben, T. Riis, M. I. Arce, G. Onandia, J. R. Paranaíba, A. Linkhorst, R. del Campo, A. M. Amado, S. Cauvy-Fraunié, S. Brothers, J. Condon, R. F. Mendonça, F. Reverey, E.-I. Rõõm, T. Datry, F. Roland, A. Laas, U. Obertegger, J.-H. Park, H. Wang, S. Kosten, R. Gómez, C. Feijoó, A. Elosegi, M. M. Sánchez-Montoya, C. M. Finlayson, M. Melita, E. S. Oliveira Junior, C. C. Muniz, L. Gómez-Gener, C. Leigh, Q. Zhang, R. Marcé