Noted environmentalist RK Pachauri died in New Delhi on Thursday. The founder-director of the city-based “The Energy and Resources Institute”, or TERI, was 79 years old.

Pachauri reportedly underwent a cardiac surgery recently, and was admitted at the Escorts Heart Institute. He had been suffering from a cardiac disease for a long time, reported The Economic Times. “It is with immense sadness that we announce the passing away of Dr RK Pachauri, the founder director of TERI,” tweeted the institution’s official account. “The entire TERI family stands with the family of Dr Pachauri in this hour of grief.”

Pachauri was the chairperson of the Intergovernmental Panel on Climate Change in 2007, when it shared the Nobel Peace Prize with former US Vice President Al Gore.

Pachauri became the chief executive of TERI in 1982, and served as the director-general from April 2001. However, the world-renowned environmentalist’s remarkable career was overshadowed by a sexual harassment scandal involving a former woman colleague at TERI. In July 2015, he was removed from his position after the institution’s Internal Complaints Committee found him guilty. Pachauri, however, consistently refuted the allegations. The environmentalist resigned from the institution’s governing council in April 2016. A court in Delhi framed molestation charges against him in October 2018.

Current TERI Director-General Ajay Mathur hailed his predecessor’s “untiring perseverance” towards establishing the institution. “He played a pivotal role in making us a leading organisation in the sustainability space,” he added.

“Dr Pachauri’s contribution to global sustainable development is unparalleled,” said TERI Chairman Nitin Desai. “His leadership of the Intergovernmental Panel on Climate Change laid the ground for climate change conversations today.”