sentences:  In recent years, Chisholm has played a visible role in opposing the use of iron fertilization as a technological fix for anthropogenic climate change.Chisholm has been a member of the United States National Academy of Sciences (NAS) since 2003 and a fellow of the American Academy of Arts and Sciences since 1992.In January 2010, she was awarded the Alexander Agassiz Medal, for "pioneering studies of the dominant photosynthetic organisms in the sea and for integrating her results into a new understanding of the global ocean."