Rajenda Pachauri, the head of the United Nations' Intergovernmental Panel on Climate Change (IPCC), resigned from his post on Tuesday after facing sexual harrassment allegations.
A spokesman for the IPCC said the 74-year-old Indian would leave his position immediately, the BBC reported.
His resignation comes as Indian police investigate a sexual harassment complaint from a 29-year-old colleague working in the offices of the New Delhi-based Energy and Resources Institute (TERI), for whom Pachauri is director-general, The Indian Express reported. He denies the allegations.
Pachauri has been chair of the IPCC since 2002, and in 2007 he collected the Nobel Peace Prize on the organization's behalf, awarded for its work in the scientific assessment of the risks and causes of climate change.
The IPCC are currently meeting in Nairobi, Kenya, and on Monday Pachauri pulled out of discussions due to what a spokesman described as "issues demanding his attention in India".
Following Pachauri's resignation, the IPCC have announced the appointment of Izmail El Gizouli as Acting Chair. Gizouli had previously been Vice Chair of the panel.