Global water cycle shifts far beyond pre-industrial conditions – planetary boundary for freshwater change transgressed
Date
2022
Authors
Porkka, Miina
Virkki, Vili
Wang-Erlandsson, Lan
Gerten, Dieter
Gleeson, Tom
Mohan, Chinchu
Fetzer, Ingo
Jaramillo, Fernando
Staal, Arie
Wierik, Sofie te
Journal Title
Journal ISSN
Volume Title
Publisher
EarthArXiv
Abstract
Human actions compromise the many life-supporting functions provided by the freshwater cycle. Yet, scientific understanding of anthropogenic freshwater change and its long-term evolution is limited. Using a multi-model ensemble of global hydrological models, we estimate how, over a 145-year industrial period, streamflow and soil moisture have deviated from pre-industrial baseline conditions (defined by 5th–95th percentiles, at 0.5° grid level and monthly time step). We find increased frequency of local deviations on ~45% of land area, mainly in regions under heavy direct or indirect human pressures. To estimate humanity’s aggregate impact on the freshwater cycle, we present the evolution of deviation occurrence at regional to global scales. Currently, local streamflow and soil moisture deviations occur on 18.2% and 15.8% of global land area, respectively, which is 8.0 and 4.7 percentage points beyond the ~3 percentage point wide pre-industrial variability envelope. Finally, we discuss applying our approach to define a planetary boundary for freshwater change. Our results indicate a substantial shift from stable pre-industrial streamflow and soil moisture conditions to persistently increasing change and a transgression of the freshwater change planetary boundary, calling for urgent actions to reduce human disturbance of the freshwater cycle.
Description
Keywords
hydrology
Citation
Porkka, M., Virkki, V., Wang-Erlandsson, L., Gerten, D., Gleeson, T., Mohan, C., Fetzer, I., Jaramillo, F., Staal, A., Wierik, S. T., Tobian, A., Van Der Ent, R., Döll, P., Flörke, M., Gosling, S., Hanasaki, N., Satoh, Y., Schmied, H. M., Wanders, N., . . . Kummu, M. (2022). Global water cycle shifts far beyond pre-industrial conditions – planetary boundary for freshwater change transgressed. EarthArXiv. https://doi.org/10.31223/x5bp8f