  Despite a surface dominated by carbon-based life, the bulk composition of the
Earth is dramatically carbon poor when compared to the material available at
formation. Bulk carbon deficiency extends into the asteroid belt representing a
fossil record of the conditions under which planets are born. The initial steps
of planet formation involve the growth of primitive sub-micron silicate and
carbon grains in the Solar Nebula. We present a solution wherein primordial
carbon grains are preferentially destroyed by oxygen atoms ignited by heating
due to stellar accretion at radii < 5 AU. This solution can account for the
bulk carbon deficiency in the Earth and meteorites, the compositional gradient
within the asteroid belt, and for growing evidence for similar carbon
deficiency in rocks surrounding other stars.
