  Despite all the efforts, there is no agreement on how temperature affects
soil carbon decay and consequently soil CO2 emission, due to overlapping of
environmental constraints. To gain further insight into the driving forces of
soil microbial processes, we herein examine the abiotic physical environment
and its potential influence on microbial activity. In this work we discuss a
mechanism which is related to temperature sensitivity of soil carbon stability
following a first-order kinetic theory. Soil carbon decomposition is linked to
diffusion and consequently to water viscosity, splitting the effects of
temperature from viscosity, here we suggest that viscosity could be a
controlling factor on bacterial mobility and nutrient diffusion. As a result,
viscosity effect on the potential soil carbon losses is demonstrated and could
be an important influence in the feedbacks of climate change on soil carbon
cycling kinetics.
