Will Steffen passed away on Sunday, 29 January. He was a giant scientist, a great communicator, a diplomat, and a warm person. His work is massively influential in both the international science community and society. His energy and collaborative spirit brought together the global change community across disciplines to understand and describe the changing Earth system.

Will was director of the International Geosphere-Biosphere Programme from 1998-2004. He was key in the evolution of the International Geosphere-Biosphere Programme (IGBP) from a collection of international projects, including Global Change and Terrestrial Ecosystems (GCTE), where he first stepped into the international global change work, to a complete jigsaw of core projects that led to an understanding of the Earth system as an integrated system including humans. He led the Great Acceleration and was pivotal in the development of the Anthropocene concept, the planetary boundaries and feedbacks between tipping points, leading to a “Hothouse Earth.” Will’s vision led to the Earth System Science Partnership, launched in 2001, which was a partnership between IGBP, IHDP, DIVERSITAS and WCRP – a collaboration upon which Future Earth was eventually built. He dedicated much of his time in dialogue with decision makers in business and policy communicating the consequences of investments or actions, like in the Sleeping Financial Giants Project.

He was a wonderful person to work with, with a kind and generous spirit taking the time to engage with young scientists and activists. He spent much of his later years communicating the gravity of the climate emergency and the urgency to act and was an active in the Australian Climate Council.

From The Conversation: “We’ve lost a giant: Vale Professor Will Steffen, climate science pioneer”

From The Guardian: “Will Steffen, ‘courageous’ climate scientist, dies in Canberra aged 75”

Words of remembrance from some of Will’s Future Earth colleagues and friends:

 “Will was a great friend and mentor. I worked under his leadership at the IGBP from 2000-2004, collaborating on the development of the Anthropocene concept and the Great Acceleration. He had a great talent to bring people together across disciplines and has been hugely influential in the field of Earth system science. He will be deeply missed.” – Wendy Broadgate, Director, Future Earth Global Secretariat Hub Sweden