The acceleration in the release of carbon from soils is one of the most important positive feedbacks related to anthropogenically induced climate change. Analyses studying the mechanisms for soil carbon release through decomposition have focused on the effect of changes in the average temperature, with little attention to changes to its variability. Anthropogenic activities are likely to modify both the average state and the variability of the climatic system; therefore, the effects of future warming on decomposition should not only focus on trends in the average temperature, but also on the change of its probability distribution. The frequency of hot or cold days and extreme events over long periods of time can potentially determine the frequency of large respiration pulses and subsequently the total amount of C stored in an ecosystem. Using analytical and numerical analyses we tested common relationships between temperature and respiration and found that the variability of temperature plays an important role determining respiration rates of soil organic matter. Changes in temperature variability, without changes in the average temperature, can either increase or decrease long-term respiration rates. Furthermore, simultaneous changes in the average and variance of temperature can either amplify or dampen the sensitivity of soil organic matter to temperature. A potential consequence of this effect of variability would be lower respiration in places where the average temperature is expected to increase but its variance to decrease.