From the Washington Post, the U.N. top man on climate policy is leaving to “work on climate and sustainability with the private sector and academia”:

LONDON (Reuters) – U.N. climate chief Yvo de Boer will step down to join a consultancy group as an adviser, he said on Thursday, two months after a Copenhagen summit failed to support a legally binding climate pact.
His decision is not expected to further derail U.N.-led climate talks to agree a successor to the Kyoto Protocol, divided over sharing the cost of cutting carbon emissions.
De Boer will leave on July 1 to join KPMG, the Secretariat for the U.N. framework convention on climate change (UNFCCC) said in a statement. He had led the agency since 2006 and his contract was expected to be extended in September.
“It was a difficult decision to make, but I believe the time is ripe for me to take on a new challenge, working on climate and sustainability with the private sector and academia,” de Boer said in the statement.
U.N. Secretary-General Ban Ki-moon will make the final decision on a replacement, a U.N. spokesman said.
“Copenhagen did not provide us with a clear agreement in legal terms, but the political commitment and sense of direction toward a low-emissions world are overwhelming. This calls for new partnerships with the business sector and I now have the chance to help make this happen,” de Boer said.