Risk transference and related trends: driving forces towards more mega-disasters

Abstract

In recent decades, the global cost of natural disasters has increased substantially. There are several trends in society and nature that suggest this pattern may continue, with more frequent mega-disasters occurring in the future. In particular, risk perception that is at odds with the “real” risk underlies the process of risk transference which encourages development that increases long-term vulnerability.

Introduction

Natural disasters occur when a natural event such as an earthquake or a storm triggers social vulnerability (Fig. 1 — top box, after Blaike et al., 1994) and the resultant damage to the physical and social fabric exceeds the ability of the affected community to recover without assistance. Occasionally “great” or “mega” disasters occur, when the need for recovery becomes truly national and/or international.

Society responds to a disaster by means of three overlapping activities: “Response and Recovery”, “Mitigation” and “Preparedness” (Fig. 1 — bottom box). These activities alter future vulnerability (and therefore the construction of future disasters), reducing risk if they are done wisely, or not if they are done otherwise. Berke and Beatley (1997, p. 2) for example, note that “disaster responses in the form of emergency relief often do not support sustainable development and, worse, sometimes subvert it” — perhaps reducing self-reliance by encouraging victim mentalities. The relationships shown in Fig. 1 depict a dynamic, interactive system, composed of both natural and social forces.

People use a variety of mechanisms or adjustments to reduce exposure to natural hazards (Burton et al., 1993). Many of these, such as dams and levees, are structural in nature, and are designed to keep natural hazards “at bay”. Building codes designed to withstand unusual loads from snow, wind or ground shaking are an important component of hazard mitigation. Other measures, such as restricting development in flood prone areas, are non-structural. Yet other approaches involve sharing the risk and impacts of disasters, through insurance, NGOs such as the Red Cross, or government disaster assistance programs.

The past few decades have seen increasing global costs as a result of natural disasters (Fig. 2, Munich Re, 1999), and increasing loss of life in many developing countries (e.g. Hewitt, 1997; Burton et al., 1993). These trends have occurred in spite of the stated goal of the United Nations International Decade for Natural Disaster Reduction (IDNDR) that the costs of natural disasters be cut in half by the year 2000.¹ They seem particularly curious because much of the world has put large and increasing resources into mitigating natural hazards.

What explains these trends? The answer is complex and — though more frequent extreme events in nature may play a role — a large part of the answer certainly lies in the realm of increased social vulnerability.