  The WMAP determination of the baryon-to-photon ratio implies, through Big
Bang nucleosynthesis, a cosmological Li abundance larger, by a factor of 2 to
3, than the Li abundance plateau observed in the oldest Pop II stars. It is
however inescapable that there be a reduction by a factor of at least 1.6 to
2.0 of the surface Li abundance during the evolution of Pop II field stars with
[Fe/H] < -1.5. That the observed Li be lower than cosmologically produced Li is
expected from stellar evolution models. Since at turnoff most of the Li
abundance reduction is caused by gravitational settling, the presence of
Lithium 6 in some turnoff stars is also understood. Given that the WMAP
implications for Li cosmological abundance and the Li Spite plateau can be
naturally explained by gravitational settling in the presence of weak
turbulence, there appears little need for exotic physics as suggested by some
authors. Instead, there is a need for a better understanding of turbulent
transport in the radiative zones of stars. This requires simulations from first
principles. Rather strict upper limits to turbulent transport are determined
for the Sun and Pop II stars.
