Terry Callaghan started as an arctic plant ecologist in 1967, working for 54 years in every arctic country. His research developed from plant ecology into ecosystem science and environmental change. He developed several scientific fields and has led many initiatives, contributing to major arctic and global organisations and environmental assessments including ACIA, SWIPA, UN Environment Programme Ozone Panel and The Intergovernmental Panel on Climate Change (IPCC).
For 14 years, he led the Abisko Scientific Research Station in Swedish Lapland and in 2001 developed the INTERACT network
, which currently joins 89 stations, and for which he is the scientific coordinator. He co-developed the Siberian Environmental Change Network.
Terry Callaghan is included as a "Most Cited and Influential Researcher" on the Web of Science. His contributions have been recognised by medals from H.M. the King of Sweden and H.M. Queen Elisabeth of England, and inclusion in the joint award of the Nobel Peace Prize to IPCC in 2007.