Looking back to the future

The emergence of climate change as a central political issue around the world, along with growing concern for the environment more generally, has raised the challenge to achieve sustainability as a high order social goal. Yet over the 20 y since the publication of the landmark Brundtland Report on sustainable development, humanity has moved further away from sustainability in many important aspects, particularly at the global scale. This paper provides an overview of the current understanding of how the human-environment relationship has evolved through time, analyzes the quest for sustainability in contemporary society, and briefly explores the implications of these analyses for the trajectory of the human-environment relationship in the twenty-first century. The focus is on an Earth systems perspective. Exploration of the human-environment relationship through time shows a fundamental switch about 200 y ago, when human society shifted from being largely the recipient of changes in Earth system functioning to becoming a global geophysical force itself, rivaling the great forces of nature in magnitude. Contemporary human societies are now on a demonstrably nonsustainable trajectory, especially with regard to climate change, with no sign at the global scale of any change in trajectory. An analysis of the sustainability gap suggests that a crucial missing component in our quest for sustainability is a failure to engage the humanities, along with the biophysical and social sciences, economics, and technology, in the search for solutions. An examination of the ways in which past civilizations have responded to external stresses and the analysis of the contemporary sustainability gap have come to the same conclusion. Those societies that respond to environmental and other stresses by transformation rather than collapse have the capability to question their core values if they become dysfunctional and to drive fundamental shifts in those values, leading to more adaptive and resilient societies.