Climate Change Science: Physics meets Complexity
Prof Will Steffen
Director, Climate Change Institute, ANU
The basic physics of the greenhouse effect has been known since the mid-1800s, and provides the fundamental scientific basis for understanding contemporary changes to climate. But to fully understand what is happening to the climate system, we need to move from the relative simplicity of the underlying physics towards the often surprising and unexpected dynamics of the climate as a complex system. The first steps along this pathway are the exploration of the energy balance at the Earth’s surface, based on the concept of radiative forcing, and the estimation of climate sensitivity to changes in radiative forcing. We then turn to observations of the climate system. What do we measure and how reliable are these measurements? Are the observations consistent with our theoretical understanding of how the climate system works? In terms of societal interest in climate change, the risks to our health and well-being from a changing climate are especially important. Finally, we consider the Earth as a whole as a complex system, and explore future pathways of contemporary climate change.
Will Steffen has a long history in international global change research, serving from 1998 to 2004 as Executive Director of the International Geosphere-Biosphere Programme (IGBP), based in Stockholm, Sweden, and before that as Executive Officer of IGBP's Global Change and Terrestrial Ecosystems project.
Prior to taking up the ANU Climate Change Institute Directorship in 2008, Steffen was the inaugural director of the ANU Fenner School of Environment and Society. From 2004 to 2011 he served as science adviser to the Australian Government Department of Climate Change. He is currently a Climate Commissioner with the Australian Government Climate Commission; Chair of the Antarctic Science Advisory Committee, Co-Director of the Canberra Urban and Regional Futures (CURF) initiative and member of the ACT Climate Change Council.
Steffen's interests span a broad range within the fields of sustainability and Earth System science, with an emphasis on the science of climate change, approaches to climate change adaptation in land systems, incorporation of human processes in Earth System modelling and analysis; and the history and future of the relationship between humans and the rest of nature.