French President Francois Hollande speaks during a news conference at the G20 leaders summit in Brisbane November 16, 2014. The meeting of leaders of the Group of 20 economies is underway in Brisbane with Australia stressing the importance of global economic issues at a summit that has been dominated by the crisis in Ukraine, climate change and the United States's Asia-Pacific pivot. REUTERS/David Gray (AUSTRALIA - Tags: POLITICS BUSINESS)

PARIS (Reuters) - French President Francois Hollande said failure to address global warming could lead to war, and called on G20 countries to act ahead of a climate change conference in Paris next year.

"We will meet again in Paris to sign a global agreement that will prevent the planet from experiencing global warming of as much as three or four degrees (Celsius), which could lead to catastrophe, if not war," Hollande said at the G20 summit in Brisbane.

"One way to prevent conflicts and catastrophe is by taking decisions."

Hollande hopes countries will sign binding agreements to limit global warming to two degrees at the conference, which will run from Nov. 30 to Dec. 11, 2015.

At the G20 summit, other nations overrode host Australia's attempts to keep climate change off the agenda and agreed to call for strong action with the aim of adopting a binding protocol at the Paris conference.

(Reporting by Geert De Clercq, editing by John Stonestreet)