[4] Karoly has served as a lead author for the Intergovernmental Panel on Climate Change (IPCC) Working Group 2 (on societal impacts) and he is a member of the faculty of the School of Earth Sciences at the University of Melbourne.

His work, along with that of the many other lead authors and review editors, contributed to the award of the 2007 Nobel Peace Prize, which was won jointly by the IPCC and Al Gore.

[5] In the Australian scene, Karoly is credited with standing up to Alan Jones, a conservative and climate change denying Sydney radio commentator with the largest daily audience in that city of ca.150,000.

[citation needed] In doing so Karoly, originally a sceptic (1980), has earned the reputation of being a climate scientist communicator with the ability to explain the complexities of his research to the general public.

On The Australian Broadcasting Corporation’s high ranking television program QndA wherein audience members can ask direct questions of experts, Karoly claimed his authority by stating in regard to his nemesis, “I am a climate scientist and Alan Jones is wrong.” [6][7] Karoly pointed out that one hundred years ago carbon dioxide in the atmosphere was 280 parts per million whereas now it is 400 parts per million, an increase of 40% which he asserted was unquestionably caused by human activity.