ANU had this to say:

Distinguished Professor Graham Farquhar AO, FAA, FRS, NAS has undertaken and led research across a broad range of fields and scales, from integration of photosynthesis with nitrogen and water use of plants, stomatal physiology, isotopic composition of plants and global change. He is a fellow of The Australian Academy of Science and of the Royal Society and a Foreign Associate of the National Academy of Sciences. He has over 300 research publications and is a leading Australian Citation Laureate.

The awards had this to say:

Graham Farquhar’s work has transformed our understanding of the world’s most important biological reaction: photosynthesis.

His models of plant biophysics have been used to understand cells, whole plants, whole forests, and to create new water-efficient wheat varieties. His latest project will determine which trees will grow faster in a high carbon dioxide world.

His work has also revealed a global climate mystery. Evaporation rates and wind speeds are slowing around the world, contrary to the predictions of most climate models. Life under climate change may be wetter than we expected.