Pioneering climate and Earth system scientist Will Steffen 1947-2023

Our dear friend and Beijer Fellow Will Steffen passed away 29 January at a hospital in Canberra, where he was treated for pancreatic cancer. He was 75. Will was a remarkable human being and a visionary scientific giant.

Our journey with Will goes back to the 1990s, when he started as the new Director of the International Geosphere and Biosphere Program (IGBP) and the Beijer Institute was in its early days. Interacting with Will, such a humble, deeply knowledgeable, curious, and creative human being has been a true privilege and pleasure.

Will is the father behind Earth System science. Early, he brought together leading scholars from diverse disciplines and backgrounds for new scientific syntheses. His book from 2004 ‘Global Change and the Earth System: A Planet under Pressure’ is a milestone and classic in this context, a systemic view of planet Earth and the human imprint altering its dynamics.

Will’s work was instrumental in generating the Great Acceleration insights, showing the increasing rate of human activity and impact upon the Earth’s biosphere and climate system. And of course, the Anthropocene and its implications as a new geological epoch where humanity has become a global force shaping the dynamics of planet Earth.

He played a critical leading role in the development of planetary boundaries and the work with the risk of irreversible climate “tipping points” that could move the world into so-called “hothouse conditions”. His curiosity led him into new forms of collaborations across the sciences and humanities. Few could see the bigger picture as Will did, and dare jumping into new explorations, generating amazing understandings and insights of profound significance.

Will’s work has truly opened new paths of scientific inquiry and will have a lasting and deep imprint. And an imprint far beyond science. Will was an active voice, a gifted communicator, and change maker, bringing into policy, practice, and business the very best of scientific understanding of complex Earth system dynamics and its implication for sustainability and the future of civilization in the fragile Biosphere.

Will’s commitments ranged from city development to national and international climate policy, from business leaders to central banks, to name a few. Fairness, respect, and appreciation was part of his humanism. He felt wonder and curiosity for life and being alive and enjoyed being part of nature revived by climbing mountains in Australia or skating on frozen lakes in Sweden.

Will’s legacy and exceptional contributions shape the way we think and act on the world and play a fundamental and profound role in the strive for transformations towards a sustainable future. It has been hugely inspirational to interact with Will, to learn, discover and be revitalized. Will’s humble personality, pleasant way of being, and great friendship will remain deeply in our hearts.