India's Rajendra Pachauri stepped down as chair of the U.N. panel of climate scientists on Tuesday, ending 13 turbulent years in charge after allegations of sexual harassment, which he has denied.
Pachauri, aged 74 and chairman of the Intergovernmental Panel on Climate Change (IPCC) since 2002, pulled out of an IPCC meeting in Kenya this week after Indian police started an investigation into a sexual harassment complaint against him.
He has denied the allegations, according to an Indian court order. Pachauri, whose second term as IPCC chair had been due to end in October 2015, has also suffered from heart problems.
In a letter to U.N. Secretary-General Ban Ki-moon, Pachauri said that his inability to travel to Kenya showed he may be unable to ensure the "strong leadership and dedication of time and full attention by the chair'' needed by the panel.
"I have, therefore, taken the decision to step down from my position as chair of the IPCC some months before completion of my term,'' he wrote.
He collected the Nobel Peace Prize on behalf of the IPCC in 2007, when the panel shared the award with former U.S. Vice President Al Gore.
Findings by the IPCC about global warming are the main guide for action by almost 200 governments which have agreed to work out a deal in December 2015 to combat climate change. The panel completed a set of mammoth reports last year.
The United Nations said the IPCC had appointed vice-chair Ismail El Gizouli as acting chair and would continue business as usual.
"The actions taken today will ensure that the IPCC's mission to assess climate change continues without interruption,'' Achim Steiner, Executive Director of the United Nations Environment Program, which oversees the IPCC, said in a statement.
Pachauri said he had considered retiring last year after the IPCC completed a series of reports that raised the probability that climate change is mainly man-made to at least 95 percent from 90 percent in its previous study in 2007.
He weathered pressure to quit after an error in the 2007 report exaggerated the rate of melt of Himalayan glaciers. An external review at the time recommended that IPCC chairs should only serve one seven-year term.