Temporal evolution of soil albedo after enhanced rock weathering amendments

Determine the time dependence of the surface albedo of agricultural or managed soils amended with crushed silicate rock for enhanced rock weathering, quantifying how albedo changes after application as the material is tilled and weathers, and assessing the persistence of albedo modification to compare its radiative forcing with the carbon dioxide removal effect over multi-year to decadal timescales.

Background

The paper argues that surface albedo modification (SAM) associated with carbon dioxide removal via enhanced rock weathering (ERW) can dominate radiative forcing relative to CO2 removal for years to decades, making the time evolution of albedo a critical unknown for climate impact assessment.

In the zero-dimensional energy balance model, the authors note that even small albedo changes can have radiative impacts comparable to gigaton-scale CO2 removal. They emphasize the lack of knowledge about how soil albedo changes over time post-application and highlight the importance of understanding the persistence of SAM under real-world practices such as tilling and repeated amendments.