Former President Mary Robinson has been charged with overseeing global efforts to tackle climate change.
United Nations secretary general Ban Ki-moon has appointed Ms Robinson as special envoy for climate change in an urgent move ahead of an international summit on the crisis within months.
The unexpected assignment means she has to immediately stand down from her role as special envoy to the Great Lakes, where she had responsibility for trying to bring peace to one of Africa’s most troubled regions.
“I have mixed emotions at handing over the role in the Great Lakes region when I make my final report to the Security Council on August 7, but ultimately I feel it is appropriate that I respond positively to the request of the secretary-general,” she said.
“His focus on climate change and his faith in my capacity to help make progress on the challenges it presents is, I believe, an affirmation of the work of the Foundation I lead.”
Ms Robinson set up The Mary Robinson Foundation – Climate Justice in 2010 to campaign for justice for victims of climate change.
“Our work on climate justice emphasises the urgency of action on climate change from a people’s perspective and I intend to take this approach in my new mandate as special envoy for climate change,” she said.
In a statement, the UN said Ms Robinson’s roles as foundation president and special envoy will be kept separate “but the synergies are very clear and should be of mutual benefit”.
“There was a degree of urgency in the appointment because of the 2014 Climate Summit which the secretary-general will host in September with heads of state and government, business, civil society amongst those invited to attend,” said a spokesman.
“Therefore the secretary-general asked Mary Robinson to accept the post, with immediate effect, which will continue to the climate talks to be held in Paris in December 2015.”
Ms Robinson, 70, was President from 1990 to 1997.
She was a UN high commissioner for human rights between 1997 and 2002.