Commons problems, common ground: Earth-surface dynamics and the social-physical interdisciplinary frontier

Abstract:

In the archetypal "tragedy of the commons" narrative, local farmers pasture their cows on the town common. Soon the common becomes crowded with cows, who graze it bare, and the arrangement of open access to a shared resource ultimately fails. The "tragedy" involves social and physical processes, but the denouement depends on who is telling the story. An economist might argue that the system collapses because each farmer always has a rational incentive to graze one more cow. An ecologist might remark that the rate of grass growth is an inherent control on the common's carrying capacity. And a geomorphologist might point out that processes of soil degradation almost always outstrip processes of soil production.

Interdisciplinary research into human–environmental systems still tends to favor disciplinary vantages. In the context of Anthropocene grand challenges – including fundamental insight into dynamics of landscape resilience, and what the dominance of human activities means for processes of change and evolution on the Earth's surface – two disciplines in particular have more to talk about than they might think. Here, I use three examples – (1) beach nourishment, (2) upstream/downstream fluvial asymmetry, and (3) current and historical "land grabbing" – to illustrate a range of interconnections between physical Earth-surface science and common-pool resource economics. In many systems, decision-making and social complexity exert stronger controls on landscape expression than do physical geomorphological processes. Conversely, human–environmental research keeps encountering multi-scale, emergent problems of resource use made 'common-pool' by water, nutrient and sediment transport dynamics. Just as Earth-surface research can benefit from decades of work on common-pool resource systems, quantitative Earth-surface science can make essential contributions to efforts addressing complex problems in environmental sustainability.