Eight years ago, he stood alongside former US vice-president Al Gore on an Oslo balcony, waving to the adoring crowds who had come to see him collect a Nobel Peace Prize.
Yesterday, Rajendra Pachauri, the former head of the UN climate change panel, was charged with the sexual assault of a female employee less than half his age at an environmental think tank. Pachauri, 75, who as chairman of the influential Intergovernmental Panel on Climate Change once advised world leaders on how to tackle global warming, is also charged with criminal intimidation, harassment and "insulting the modesty of a woman".
The charge sheet includes the names of 23 prosecution witnesses including former colleagues who are ready to testify against him. The sexual harassment claims, all denied by Mr Pachauri, came to light in February last year, when a 29-year-old research assistant filed a police complaint accusing him of sending her inappropriate texts and emails.
Amid a police inquiry, he resigned as chairman of the IPCC, citing health reasons. In July, he was relieved of his leadership of The Energy and Resources Institute, the Delhi think tank where the harassment claims originated. A second woman also alleges she was subject to his sexual advances.
Mr Pachauri claims lewd messages received by the first woman followed his email and phone being hacked.