Climate campaigner Al Gore has canceled a lecture he was supposed to deliver in Copenhagen.
The former vice president and Nobel Peace Prize winner had been scheduled to speak to more than 3,000 people at a Dec. 16 event hosted by the Berlingske Tidende newspaper group.
The group says Gore canceled the lecture Thursday, citing unforeseen changes in his schedule.
Gore spokeswoman Kalee Kreider says the decision was made because of "all the events going on with the summit." Dec. 16 is a key date for the meeting because that's when the ministerial segment starts.
Chief editor Lisbeth Knudsen says it's a "great disappointment" that Gore canceled and that all tickets will be refunded.