Tradeoff of CO2 and CH4 Emissions from Global Peatlands under Waer-table Drawdown
Huang, Y., Ciais, P., Luo, Y., Zhu, D., Wang, Y., Qiu, C., Goll, D. S., Guenet, B., Makowski, D., Graaf, I. D., Leifeld, J., Kwon, M. J., Hu, J., & Qu, L. (2021). Tradeoff of CO2 and CH4 Emissions from Global Peatlands under Waer-table Drawdown. Nature Climate Change. 11, 618-622. DOI:10.1038/s41558-021-01059-w.
Water-table drawdown across peatlands increases carbon dioxide (CO2) and reduces methane (CH4) emissions. The net climatic effect remains unclear. Based on global observations from 130 sites, we found a positive (warming) net climate effect of water-table drawdown. Using a machine-learning-based upscaling approach, we predict that peatland water-table drawdown driven by climate drying and human activities will increase CO2 emissions by 1.13 (95% interval: 0.88–1.50) Gt yrâˆ'1 and reduce CH4 by 0.26 (0.14–0.52)â€‰GtCO2-eqâ€‰yrâˆ'1, resulting in a net increase of greenhouse gas of 0.86 (0.36–1.36)â€‰GtCO2-eqâ€‰yrâˆ'1 by the end of the twenty-first century under the RCP8.5 climate scenario. This drops to 0.73 (0.2–1.2)â€‰GtCO2-eqâ€‰yrâˆ'1 under RCP2.6. Our results point to an urgent need to preserve pristine and rehabilitate drained peatlands to decelerate the positive feedback among water-table drawdown, increased greenhouse gas emissions and climate warming.