World

More than 100 world leaders told at United Nations to act now on climate change

  • British Prime Minister David Cameron addresses the Climate Summit, at United Nations headquarters, Tuesday, Sept. 23, 2014. (AP Photo/Richard Drew)

    British Prime Minister David Cameron addresses the Climate Summit, at United Nations headquarters, Tuesday, Sept. 23, 2014. (AP Photo/Richard Drew)  (The Associated Press)

  • British Prime Minister David Cameron speaks during the United Nation Climate Summit at U.N. headquarters, Tuesday, Sept. 23, 2014. (AP Photo/Seth Wenig)

    British Prime Minister David Cameron speaks during the United Nation Climate Summit at U.N. headquarters, Tuesday, Sept. 23, 2014. (AP Photo/Seth Wenig)  (The Associated Press)

  • United Nations Secretary-General Ban Ki-moon, left, delivers remarks as President Francois Hollande of France looks on at a news conference on climate change during the Climate Summit at U.N. headquarters, Tuesday, Sept. 23, 2014. (AP Photo/Jason DeCrow)

    United Nations Secretary-General Ban Ki-moon, left, delivers remarks as President Francois Hollande of France looks on at a news conference on climate change during the Climate Summit at U.N. headquarters, Tuesday, Sept. 23, 2014. (AP Photo/Jason DeCrow)  (The Associated Press)

United Nations Secretary-General Ban Ki-Moon is challenging more than 100 world leaders to set a new course for a warming world and reverse the rise of heat-trapping gases.

Tuesday's one-day climate summit at the annual United Nations gathering of world leaders is a forum for non-binding pledges. It is designed to lay the groundwork for a new global treaty to tackle climate change due at the end of next year.

Ban said the world is facing an unprecedented challenge. He said Earth needs all hands on deck to weather the storm of climate change.