Self-organizing change? On drivers, causes and global environmental change

Within global environmental change research, certain external drivers generally are assumed to cause the environmental system to change. The most commonly considered drivers are relief, sea level, hydroclimate, and/or people. However, complexity theory and self-organizing systems provide a very different framework and means of explanation. Self-organization - understood as the aggregate processes internal to an environmental system that lead to a distinctive spatial, temporal, or other organization - reduces the possibility of implicating a specific process as being causal. The principle of equifinality, whereby two or more different drivers can generate the same form, has long been recognized within a process-response framework, as well as the concept of divergence, which states that similar causes or processes result in different effects. Both ideas differ from self-organization in that they (i) deal with drivers external to the system and (ii) imply concrete cause-and-effect relations that might be difficult to discern. The assumption is, however, that careful study will eventually lead to the true causes and processes. Studies of self-organization deal with the ways in which internal processes interact and may drive a system toward an instability threshold, the so-called bifurcation point. At this point the system develops by chance and no single external or internal cause for the change can be defined. For research into environmental change this is a crucial theory for two reasons: environmental reconstruction needs to take into account the possibility that past changes may have occurred without any change in the external drivers, and current changes may also be entirely caused by internal system dynamics, reflecting processes arising from the interactions between the system components. Whilst some authors have inferred that environmental reconstruction is, in principle, impossible and that contemporary global environmental change is inscrutable, this paper concludes that such an argumentation is unnecessarily pessimistic. We argue that the focus on self-organization provides important caveats in relation to studies that attribute all environmental change to external drivers and that a multitude of independently existing geomorphological concepts - such as singularity, extrinsic and intrinsic thresholds, and sensitivity - can be well framed and combined within the concept of self-organization. (C) 2015 Elsevier B.V. All rights reserved.