  I have suggested that one possible solution of the Boltzmann brain problem is
that the universe is decaying at an astronomical rate, making it likely to
decay within 20 billion years. A problem with this suggestion is that it seems
to require unnatural fine tuning in the decay mechanism that would not be
explained anthropically. Here it is pointed out that if a spacetime version of
volume averaging were used in the cosmological measure problem, this would give
anthropic support for an impending cosmic doomsday.
