  It is an open, but not unanswerable, question as to how much atmospheric CO2
is sequestered globally by vegetation fires. In this work I conceptualise the
question in terms of the general CharXive Challenge, discuss a mechanism by
which thermoconversion of biomass may regulate the global distribution of
carbon between reservoirs, show how suppression of vegetation fires by human
activities may increase the fraction of carbon in the atmospheric pool, and
pose three specific CharXive Challenges of crucial strategic significance to
our management of global carbon cycles.
