BBC: The UN's top climate diplomat, Christiana Figueres, has said she will leave her post in July. Ms Figueres said she would not accept an extension of her appointment which finishes this summer. As executive secretary of the UN Framework Convention on Climate Change, she played a key role in the talks that lead to the Paris Climate Agreement. Her contribution to the negotiation process was praised as "really extraordinary". Ms Figueres became executive secretary in the wake of the Copenhagen climate...