Shedding Light on Lithium Evolution: The Globular Cluster Perspective
  I shall review what has been learnt during 20 years of lithium observations
in stars belonging to metal-poor globular clusters. The focus will be on little
evolved main-sequence, turnoff-point (TOP) and subgiant-branch (SGB) stars
expected to display Spite-plateau lithium abundances like those found in the
majority of field stars of similar metallicities. But is the Spite plateau of
globular clusters the same as those of field stars? What effect does, e.g.,
cluster-internal pollution have on lithium abundances in the now dominant
second generation of stars? It will be shown that it is primarily our
incomplete knowledge of the temperature scale of Population II stars which
currently limits the diagnostic power of globular clusters as regards the
stellar-surface evolution of lithium.
