The Effect of a Warmer Climate on Soil Carbon Cycling: Emergent Responses Across Time and Space Scales.

The Effect of a Warmer Climate on Soil Carbon Cycling: Emergent responses across time and space scales

Globally, atmospheric warming is the most certain climate impact of increasing atmospheric greenhouse gas concentrations. This warming will lead to warmer soils fairly rapidly. For example, 80% of a step-change in air temperature will be realized at 1 m depth within a year (all else equal). It is well established that temperature has immediate, direct effects on decomposition rates (e.g., through effects on enzyme activity, binding energies, and reaction kinetics). At longer time scales, evidence is emerging for microbial acclimation or changes in carbon use efficiency. Perhaps even more challenging, longer time scales of warming will lead to changes in vegetation, soil properties, and even, in permafrost regions, large changes in landscape topography and inundation. These ecosystem- and landscape-level impacts of warming may dominate the effects of climate change decomposition and soil carbon losses, and need to be integrated into our experimental and predictive frameworks.