http://www.reuters.com/article/2013/12/23/us-climate-un-idUSBRE9BM0KM20131223

U.N. Secretary-General Ban Ki-moon on Monday appointed former Ghana President John Kufuor and former Norwegian Prime Minister Jens Stoltenberg as special envoys on climate change to drum up support for a planned global conference in September.

Ban has invited world leaders, chief executives and civil society groups to a Climate Summit in New York on September 23 to push for robust action on climate change by reducing greenhouse gas emissions and building climate resilient communities.

"As part of their work, the special envoys will assist the Secretary-General in his consultations with leaders to raise the level of ambition to address climate change and to accelerate action," Ban's office said in a statement.

"They will also provide strategic advice to the Secretary-General based on their consultations," it said.

Kufuor was Ghana's president from 2001-2009 and chairman of the African Union from 2007-2008, while Stoltenberg was prime minister of Norway from 2000-2001 and again from 2005-2013.