The World Federation of Scientists is a multi-disciplinary association of scientists known for climate change denialism, associated with right-wing think tank the Heartland Institute. Established in Erice, Sicily in 1973 by a group led by Isidor Isaac Rabi and Antonino Zichichi, it has grown to include more than 10,000 scientists drawn from 110 countries. It holds annual seminars on planetary threats, discussing issues such as adaption to and mitigation of global climate change. Václav Klaus, then President of the Czech Republic, gave the keynote lecture of their August 2012 meeting, his skeptical views sparking debate among the attendees. It is not related to the World Federation of Science Journalists or World Federation of Scientific Workers.