Fire strongly influences carbon cycling and storage in boreal forests. In the near-term, if global warming occurs, the frequency and intensity of fires in boreal forests are likely to increase significantly. A sensitivity analysis on the relationship between fire and carbon storage in the living-biomass and ground-layer compartments of boreal forests was performed to determine how the carbon stocks would be expected to change as a result of global warming. A model was developed to study this sensitivity. The model shows if the annual area burned in boreal forests increases by 50%, as predicted by some studies, then the amount of carbon stored in the ground layer would decrease between 3.5 and 5.6 kg/m^2, and the amount of carbon stored in the living biomass would increase by 1.2 kg/m^2. There would be a net loss of carbon in boreal forests between 2.3 and 4.4 kg/m^2, or 27.1-51.9 Pg on a global scale. Because the carbon in the ground layer is lost more quickly than carbon is accumulated in living biomass, this could lead to a short-term release of carbon over the next 50-100 yr at a rate of 0.33-0.8 Pg/yr, dependent on the distribution of carbon between organic and mineral soil in the ground layer (which is presently not well-understood) and the increase in fire frequency caused by global warming.