Disaster risks are rapidly increasing around the world. Most disaster risk assessments are focused on current risks, rather than drivers of risks or their dynamics. Drivers are in the control of policymakers, society and individuals but accurate assessment and continuous re-evaluation of risk are required to enable effective risk reduction and prevent drastic increases in future loses. The paper calls for a review of the range of efforts to quantify future risk in order to consider how to best apply this information.
This publication offers an overview of the problem of evolving risk, as well as the factors driving its evolution. It discusses some of the issues that complicate quantification efforts, as well as steps that can be taken to mitigate the ongoing increase in risk in a number of policy areas that can strongly affect the future disaster risk.
The combined dynamics of the following three elements influence disaster risk: the occurrence of potentially dangerous events such as earthquakes or topical cyclones (hazard); the population and economic assets located in hazard-prone areas (exposure); and the susceptibility of the exposed elements to the natural hazard (vulnerability). Most disaster risk assessments focus on current risks, not the drivers of risk. Policy decisions based on such assessments can underestimate risk if they do not take into account the continuous and sometimes rapid changes in the drivers of risk:
- Climate change drives hazard: raising sea levels, changing the intensity and frequency of storms, increasing temperatures, and altering patterns of precipitation.
- Population growth in hazardous areas and improved socioeconomic conditions increases exposure. Urbanisation in particular, results in larger concentrations of exposure. In Indonesia, for example, river flood risk may increase 166 percent over the next 3 decades as a result of rapidly expanding urban areas.
- Urban and socio-economic development also affects vulnerability. Some people become less vulnerable because of improved construction and a more prosperous economic situation. However, in many areas structural vulnerability continues, with unregulated building practices and unplanned development. For example, earthquake risk in Kathmandu is expected to double to 50 percent by 2045 due to informal building expansion.
Drivers of future risk are within the control of decision makers today. Promoting policies that reduce risk and avoiding maladaptive actions that increase risk can positively influence the risk environment of the future:
- Climate change mitigation through reducing greenhouse gases remains key to preventing strong increases in climate-related hazard.
- A robust hazard protection strategy that includes ecosystem –based measures can help to limit the harm caused by changes in frequency and intensity of hazard.
- Strengthening construction practices and improving disaster preparedness can address vulnerability.
Failing to account for these drivers in risk assessments reduces the opportunity to highlight long-term cost-effective options for risk reduction. This is not a result of inappropriate or absence tools, but the way in which the information used represents a particular moment in time. Risk specialists are better equipped than ever to focus on assessing risk under future climate conditions:
- Capturing disaster risk assessment through the implementation of climate change scenarios in global and regional climate models makes it possible to incorporate changes in intensity and frequency of extreme weather to project future flood, drought, cyclone, heat, and storm surge risk.
- Stimulating the expansion of urban areas, projecting future population distribution and implementing Shared Socioeconomic Pathways as scenarios of future conditions can be carried out to demonstrate the influence of changing exposure on disaster risk.
- Projecting future vulnerability has not yet been addressed extensively in risk assessments as the range of interdependent factors determining social vulnerability make it difficult to predict. However, adjusting estimates of structural vulnerability can reflect projected changes in construction.