I am not a soil expert but will use my little experience in bio-char in soil to explaining the dynamics; Of course temperature affects fluidity of water/liquid. Now Co2 or black carbon or biochar in soil help absorb a lot of water and releases it in relation to temperature in the soil.. therefore the flow rate of diffusion of water in soil inversely proportional to temperature. Co2 has micro pores that absorb a lot of water in soil. Please read these articles;Sensitivity of Soil Respiration to Variability in Soil Moisture and Temperature in a Humid Tropical Forest
Tana E. Wood , Matteo Detto, Whendee L. Silver
Published: December 2, 2013http://dx.doi.org/10.1371/journal.pone.0080965,
Moisture and soil texture effects on soil CO2 efflux components in southeastern mixed pine forests
John J. Dilustro, , Beverly Collins, Lisa Duncan, Chris Crawford