Climate Scenarios and Decision Making under Uncertainty

Abstract

Climate scenarios provide an essential foundation for research on the impacts of climate change on the built environment and for the identification of appropriate adaptation measures. They are, however, subject to uncertainties in the underlying greenhouse gas emissions and concentration scenarios as well as a range of scientific uncertainties associated with climate modelling and the natural variability of climate. These uncertainties provide a major motive for the current move towards probabilistic climate scenarios -a move which is also supported from the decision-making perspective. Examples of probabilistic scenarios constructed for variables and UK locations of interest for built environment research are presented here. The need to consider other uncertainties -potentially important sub-grid scale processes such as the urban heat island effect and the influence of natural variability in non-stationary series of weather extremes -is demonstrated. Consideration is also given to aspects of decision making under uncertainty -focusing on the timing of upgrade of the Thames tidal defences and the extent to which managers integrate climate change information into long-term projects in the built environment. A major recommendation from the case-study examples presented here is the need for improved communication between climate scenario developers, and scenario users and decision makers in the built environment sector.

Climate change adaptation in European river basins

“…This lack of an adequate response in all case-studies is noteworthy, since droughts have already caused enormous adverse social, economic, and environmental effects in recent years (Della-Marta et al 2007: 252;EM-DAT 2008), and it is expected that this will become even worse due to climate change (IPCC 2007). Climate change models project more frequent and intense summer droughts across many parts of Europe, particularly in the southern part (Goodess et al 2007;EEA 2005). This may be further exacerbated because of an increasing demand for water as a result of elevated temperatures (EEA 2005).…”

“…It shows nevertheless that flood and drought problems become more visible and cannot be ignored. Especially since climate change models project more frequent and intense summer droughts across many parts of Europe, particularly in the southern part (Goodess et al 2007;Fowler et al 2007). This may be further exacerbated because of an increasing demand for water as a result of elevated temperatures.…”

Taming global flood disasters. Lessons learned from Dutch experience

“…Nevertheless, the resulting policies remained ad hoc and post hoc responses to disasters, and as a consequence, the measures evolved over time in a piecemeal and fragmented way. This approach has worked reasonably well in the recent past, when the external drivers were assumed to change only slowly in comparison with the expected lifetime of the infrastructure systems, but this is no longer tenable due to a faster pace of change (Goodess et al 2009;Hulme et al 2009;Gersonius et al 2010).…”

Toward a Sustainable and Resilient Future

“…Alternative approaches have focused first on scenarios of radiative forcing, followed by an analysis of the combinations of economic, technological, demographic, policy, and institutional factors that can influence such trajectories (Moss et al, 2010). Other approaches are based on robust decisionmaking (e.g., Groves and Lempert, 2007;Lempert and Collins, 2007;Groves et al, 2008); information gap analysis (Hine and Hall, 2010); or on the search for co-benefits, no regrets strategies, flexibility, and reversibility (e.g., Fankhauser et al, 1999;Goodess et al, 2007;Hallegatte, 2009). …”