Extreme Events as Pacemaker of Adaptation to Climate Change

For variety of reasons, extreme events are thought of as propelling adaptation to climate change (Füssel, 2007; IPCC, 2012). In the simplest formulation of this logical assertion, extreme weather and climate events transcend the signal-to-noise threshold and make climate risks starkly evident to decision-makers. Similarly, they make latent societal vulnerability manifest, and overcome economic and political barriers to adaptation. These effects can in theory hold for a stationary climate, whereby extreme events override people’s tendency to disregard low probability, and thus infrequent, impacts, especially as time passes without an occurrence. But the signaling effect of extremes is now often invoked for adaptation to a changing climate: an underlying trend in, say, mean temperature, may be difficult for any decision-maker to discern, but more frequent excursions into conditions rare, or even unknown, in the past, become hard to ignore. Framed by a discourse on climate change, an extreme event becomes not just a reminder that climate distributions have tails, but a harbinger of more extremes to come. So extremes are framed descriptively as propelling adaptation and prescriptively as potentially efficient pacemakers of adaptation (Larsen et al., 2008). The title of the IPCC special report, “Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation” clearly invokes this prescriptive role for extremes. Yet several social processes appear to countervail, or at least weaken, the pacemaker effect of extremes. Recent analyses of (and debates over) attribution of extreme events to climate change (Dole et al., 2011; Rahmstorf and Coumou, 2011) reveal that even events that could easily be once-in-a-lifetime experiences for those involved do not unambiguously signal trends, nor necessarily convince decision-makers that they are experiencing climate change or are already in a fundamentally different climate (Adam, 2011; editors, 2011). A recent survey reveals that Americans rather readily attribute extreme weather to anthropogenic climate trends (Leiserowitz et al., 2012), but this does not necessarily yield more public support for mitigation or adaptation investments . Both lay and technical people seem more puzzled than provoked by extremes in this awkward era in which anthropogenic climate change is widely predicted, and perhaps just barely discernible (Seneviratne et al., 2012), yet is still hotly debated (Risbey, 2008) Limits on the effectiveness of hazard mitigation across decades of extreme events (White et al., 2001), some that expressly evoked policies meant to curb future losses (Birkland, 2006), cast further doubt on the notion that extremes might be counted on to propel effective adaptation to a changing climate. And the prescription frequently offered that we should better adapt to current extremes as a first step in adapting to future climate change (often framed as lowor noregrets options) implies an inadequacy of current adaptation that, for some unspecified reason,