Abstract
Drylands cover 40–50% of the Earth’s surface and make an important contribution to the terrestrial carbon sink and the global carbon cycle. However, in addition to extended dry periods, drylands also experience extreme flood events. Here we report carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions from flooded drylands in central Australia (Kati-Thanda-Lake-Eyre basin; KTLE) in 2019. At the time of sampling the wet areas of the KTLE emitted 1.4 ± 0.6 Tg CO2 d− 1 and 0.31 ± 0.13 Gg CH4 d− 1 (24.6 ± 10.6 Gg CO2e) and consumed 3.0 ± 1.3 Mg N2O d− 1 (0.8 ± 0.4 Gg CO2e). The low basin slope resulted in a large area of inundation (up to 33,547 km2), that remained wet for an extended period. Up-scaling the daily fluxes for the changing wet surface area, for the wet period, has the potential to result in 127.1 ± 59.6 Tg of CO2 and 22.2 ± 10.5 Gg of CH4 (1.8 ± 0.8 Tg CO2e) emitted, and 2.5 ± 1.3 Gg of N2O (0.7 ± 0.3 Tg CO2e) consumed (Total = 129.6 ± 59.2 Tg CO2e). The low gradient and associated low volume of water transported and large wet area also resulted in the vertical flux of carbon being much more important than the river transported carbon. This first-order estimate of GHG emissions from the KTLE suggests that when flooded, dryland systems globally have the potential to make a significant (e.g. 2.8% of annual global inland river CO2 emissions), but currently unaccounted for, contribution to global GHG emissions, and may need to be included as feedback in global climate models.
Data availability
All data used in this manuscript is provided in the Supporting Information.
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Acknowledgements
We thank Hylton Ward from Elite Aviation Services for flying us safely around one of the most remote places on the planet. Iain Alexander did the surface area estimates. We thank Anju Rana for assessing the response of the Lake Eyre basin to climate change, Pep Canadell for helpful discussions and four reviewers for helpful comments that improved the manuscript. This work was supported by ARC Grant DP220100918 awarded to BDE.
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B.D.E. conceived the project. B.D.E and D.E undertook the field work. B.D.E and J.A.R did the data analysis. B.D.E. wrote the manuscript with input from J.A.R and D.E. All authors reviewed and edited the manuscript.
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Eyre, B.D., Rosentreter, J.A. & Erler, D.V. Significant greenhouse gas emissions from flooded drylands in Kati Thanda Lake Eyre basin in Australia. Sci Rep (2026). https://doi.org/10.1038/s41598-026-35915-6
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DOI: https://doi.org/10.1038/s41598-026-35915-6
