Since the analysis uses normalized losses that remove the influence of inflation, population and wealth, one can then use scenarios about how these parameters will change in the future to estimate the value of future losses. But this approach cannot take into account other changes, like building norms, protection measures, etc. Only physical models can explicitly take into account how, for example, a change in building norms could reduce hurricane losses.
Numerous actions have been undertaken in the last one hundred years to reduce hurricane damages and these actions demonstrate that adaptation can be effective. First, there are investments in new protection infrastructures like flood protection systems, dams and building elevations. For example, the sea wall built in Galveston in the aftermath of the 1900 hurricane largely mitigated the consequences of Alicia's landfall in 1983. On a smaller scale, the town of Belhaven, Florida, in the aftermath of hurricane Fran (in 1996), implemented a program to elevate 379 houses. When hurricane Floyd struck in 1999, damages were reduced by 80%, thanks to this program (Williams, 2002). Hopefully, the new protection system that is currently built in New Orleans will be more efficient that the system in place before Katrina in 2005.
Second, building codes have been improved and they have limited hurricane damages. The best example is the building code implemented in Florida after Andrew's landfall, even though its effects are only starting to be visible. Also, existing norms have been enforced more rigorously, since hurricanes have shown that the lack of compliance with existing rules had significantly increased damages. The impact of building codes is far from negligible: according to Ryland (2002), ''if all buildings in South Florida were either retrofitted or in compliance with the postAndrew South Florida Building Code, or the new Florida Building Code that went into effect this year , another Hurricane Andrew would cause only about half as much damage to residences and 40 percent less damage to commercial property. The combined loss reduction would be about $10.4 billion, according to the study''.
Third, hurricane track forecasts have improved and better warning systems have been implemented to help people and business to prepare for hurricane landfalls and avoid damages. With early warning, people and businesses can protect houses and suspend dangerous industrial processes, which in turn will reduce direct and indirect damages. For instance, flood damages experts quoted in Carsell (2004) estimate that a 48-hour warning can reduce flood damages by up to 50%, thanks to small-scale preparation actions inside houses. Also, protecting windows reduces wind damages by 12 to 54 percent (Williams, 2002). Preparing industrial facilities can also avoid large pollution and other ancillary damages that can be deadly and costly (e.g., RMS, 2005).
Fourth, individual responses to natural risks may have improved thanks to the direct observation of hurricane consequences or thanks to educational efforts implemented in disaster aftermaths. Nathe (2000) assess the efficacy of public education to reduce earthquake losses and this analysis has parallels with other types of natural disaster.
Most importantly for future vulnerability, much can be done to reduce risk through urban planning and land-use management (Burby and Dalton, 1994). According to the National Research Council's Board on Natural Disasters (1999), ''Communities can often achieve significant reductions in losses from natural disasters by adopting land-use plans,'' and the Second National Assessment on Natural and Related Technological Hazards concluded that ''No single approach to bringing sustainable hazard mitigation into existence shows more promise at this time than increased use of sound and equitable land-use management'' (Mileti 1999). It seems, therefore, that including risk management in land-use planning could very efficiently reduce vulnerability to hurricanes and therefore reduce the direct losses from hurricane. The drawback of this method is its long timescale for implementation. A building has a long lifetime and the stock of buildings already present cannot be replaced instantaneously. Better land-use management would reduce hurricane damages only after several decades. Looking forward to assess hurricane risks by the end of this century, however, it is possible that improved land-use and urban planning could decrease vulnerability and largely compensate for almost any increase in hurricane risk.
When considering adaptation, however, one has to look at the details of how adaptation strategies can be implemented. In particular, as demonstrated in Hallegatte (2006) and Hallegatte et al. (2007a), uncertainty about future climate is a strong obstacle to the implementation of adaptation measures. Indeed, while the cost of adaptation is immediate, the benefits from adaptation measures are uncertain and delayed in the future. For instance, rejecting building permits in a zone that may become excessively vulnerable to hurricane storm surge if hurricane intensity increases in the future has an immediate political and economic cost. But the benefits of such a measure, namely limiting losses from future property expropriation because hurricane risk has become too high, are uncertain. These benefits depend on how hurricane characteristics will change in the future, which is still largely unknown. It is understandable, therefore, that costly adaptation and risk-management decisions are not always made, in spite of estimates suggesting that there will be long term benefits if climate change projections are correct. To improve this situation, innovative decision-making frameworks have to be promoted, especially those that favour decisions that can be reversed if necessary. As an example, allowing the urbanization of an area is hardly reversible: when buildings have been built, it is economically and politically costly to retreat from the area. On the opposite, prohibiting the urbanization of an area is highly reversible, since urbanization can then be allowed at any time and at no cost. In presence of uncertainty, the latter option should, therefore, be valued higher.
Regardless, it is important to make a difference between (i) optimal adaptation measures that can be theoretically implemented if future climate and risks were known, and if decision-making processes were perfectly rational, and (ii) realistic adaptation strategies, that take into account political and economic constraints and uncertainties about future climate.
To measure the benefits from adaptation measures, it is essential to take into account also their negative side-effects. For instance, in the case of coastal infrastructure to protect against storm surge such as sea walls, these may threaten the tourism industry because they change landscape, ecosystem health and beach leisure attractions. Coastal attractiveness for leisure and tourism activities is closely linked to various parameters such as landscapes (Lothian, 2006), the quality of the environment, water availability, etc. As a consequence, in some contexts, hard protection would simply not be an option.
Also, even if successful cases do exist, geographers around the world have repeatedly demonstrated that adverse effects of dike construction are almost the norm in the past decades (see e.g. Paskoff, 1994). Beach landscape degradation, marine ecosystem damage and loss of leisure activity (e.g. diving) would surely lead to a drastic reduction in tourism flows - or at least to a decrease in the willingness to pay of tourists - leading in turn to declining local incomes. Equally important, hard protection could contribute to fish stocks depletion by further damaging coastal ecosystems (Clark, 1996). Since 90 percent of fishes depend on coastal zones at one point in their life cycle (Scialabba, 1998), such impacts could have a significant impact on economic income from fisheries.
Was this article helpful?
This is common knowledge that disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.