Soil Carbon Losses Reduce Soil Moisture in Global Climate Model Simulations

Earth Interactions

article

Sonali Shukla McDermid¹  Ensheng Weng³  Michael Puma³  Benjamin Cook²  Tomislav Hengl⁵  Jonathan Sanderman⁶  Gabrielle J. M. De Lannoy⁷  Igor Aleinov³ 

[1] Department of Environmental Studies, New York University;NASA Goddard Institute for Space Studies;Center for Climate Systems Research, Columbia University;Lamont-Doherty Earth Observatory, Columbia University;OpenGeoHub Foundation/Envirometrix Ltd.;Woodwell Climate Research Center;Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven

关键词: Atmosphere-land interaction;    Anthropogenic effects/forcing;    Biosphere-atmosphere interaction;    Climatology;    Soil moisture;    Water budget/balance;   

DOI  :  10.1175/EI-D-22-0003.1

学科分类：地球科学(综合)

来源: American Geophysical Union

【 摘 要 】

Most agricultural soils have experienced substantial soil organic carbon losses in time. These losses motivate recent calls to restore organic carbon in agricultural lands to improve biogeochemical cycling and for climate change mitigation. Declines in organic carbon also reduce soil infiltration and water holding capacity, which may have important effects on regional hydrology and climate. To explore the regional hydroclimate impacts of soil organic carbon changes, we conduct new global climate model experiments with NASA Goddard Institute for Space Studies ModelE that include spatially explicit soil organic carbon concentrations associated with different human land management scenarios. Compared to a “no land use” case, a year 2010 soil degradation scenario, in which organic carbon content (OCC; weight %) is reduced by a factor of ∼0.12 on average across agricultural soils, resulted in soil moisture losses between 0.5 and 1 temporal standard deviations over eastern Asia, northern Europe, and the eastern United States. In a more extreme idealized scenario where OCC is reduced uniformly by 0.66 across agricultural soils, soil moisture losses exceed one standard deviation in both hemispheres. Within the model, these soil moisture declines occur primarily due to reductions in porosity (and to a lesser extent infiltration) that overall soil water holding capacity. These results demonstrate that changes in soil organic carbon can have meaningful, large-scale effects on regional hydroclimate and should be considered in climate model evaluations and developments. Further, this also suggests that soil restoration efforts targeting the carbon cycle are likely to have additional benefits for improving drought resilience.

【 授权许可】

Unknown