GENEVA, Nov 25 (Reuters) - A "business as usual" approach to climate change could lead to a rise in global temperatures of 6 degrees or more, the head of the U.N. weather agency said on Wednesday.

However, decisions taken at a meeting of world leaders in Paris next week could still mean temperatures stay within 2 degrees Celsius of pre-industrial averages.

"Yes, it's still possible to keep to the 2-degree target but the more we wait for action the more difficult it will be," Michel Jarraud told a news conference.

(Reporting by Tom Miles; Editing by Louise Ireland) ((tom.miles@thomsonreuters.com; +41 22 733 38 31; Reuters Messaging: tom.miles.reuters.com@reuters.net))