Prominent climate scientist Professor Will Steffen has been remembered by colleagues and friends as a generous and courageous pioneer for climate action after his death aged 75.
Tributes have flooded social media for Professor Steffen, who died in Canberra on Sunday. He had been receiving treatment for pancreatic cancer.
The Australian National University (ANU) remembered its emeritus professor as "one of Australia's most influential and respected climate scientists".
Professor Steffen served as executive director of the International Geosphere-Biosphere Programme, and was a contributor to five Intergovernmental Panel on Climate Change (IPCC) reports.
In a statement, ANU said the internationally esteemed expert would leave behind a lasting legacy as the former director of the ANU Fenner School of Environment and Society, and the inaugural director of the ANU Climate Institute.
Fenner School senior lecturer Dr Joelle Gergis described Professor Steffen as a visionary, a brilliant scientist and a gifted communicator "who was so generous with his time".
"He was so supportive of people like me coming through the ranks," Dr Gergis said.
"He leaves an extraordinary legacy as one of the greats of our time.
"It is such a loss for our community."
In a tweet, sustainability adviser and businesswoman Sam Mostyn described Professor Steffen as "the most generous, courageous, humble & selfless pioneer for climate action".
Professor Steffen also made substantial contributions to science policy, serving as an adviser to the Australian government's Department of Climate Change and Energy Efficiency, Climate Commission, and Climate Council.
His research spanned a broad range within Earth system science, with an emphasis on sustainability and climate change.
Professor Steffen was tireless in educating the public, engaging with policy and supporting fellow researchers.
Director of the Institute for Climate, Energy and Disaster Solutions (ICEDS) Professor Mark Howden honoured his passion for climate science.
"Will was instrumental in alerting the Australian public to the challenges of climate change and the need for strong and rapid emission reductions, particularly through his work with the Climate Council," he said.
Head of Energy at ICEDS Frank Jotzo described Professor Steffen as "a great thinker on climate change".
"I owe him much," Professor Jotzo said.
"I will remember him as a gentle, positive human being who made a difference in how the world understands climate change."
