The United States DOE has set for transportation applications the target of 6.0 wt% of H2 storage capacity and volumetric energy density of 1.5 kWh/L at operating temperature and pressure conditions of 50°C and 2.5 bar respectively by 2010. Out of the many approaches that are being explored for storing hydrogen, none has been able to satisfy all those requirements. Hydrogen storage is therefore the key enabling technology that should be significantly advanced in terms of performance and cost effectiveness if hydrogen is to become an important part of the world's energy economy. In this work, the role of carbon in the hydrogen desorption kinetics of different carbon-doped light metal hydrides is evaluated using Density Functional Theory calculations. Carbon is introduced as a dopant in the lattice structure of light metal hydrides like lithium beryllium hydride, Li2BeH4. The presence of one or two carbon atoms in the crystal lattice of Li2BeH4 is seen to elongate the Be-H bonds in the strong covalently bound [BeH 4]2- tetrahedrons by an amount of 1Å to 3Å. This increase in that bond length implies the weakening of the Be-H bond strength, and therefore inherent reduction in the hydrogen desorption temperature in Li2BeH4 upon carbon addition.