• Energy Research

There is considerable uncertainty surrounding future changes in tropical cyclone (TC) frequency and intensity, particularly at local scales. This uncertainty complicates risk assessments and implementation of risk mitigation strategies. We present a novel approach to overcome this problem, using the statistical model STORM to generate 10,000 years of synthetic TCs under past (1980–2017) and future climate (SSP585; 2015–2050) conditions from an ensemble of four high-resolution climate models. We then derive high-resolution (10-km) wind speed return period maps up to 1000 years to assess local-scale changes in wind speed probabilities. Our results indicate that the probability of intense TCs, on average, more than doubles in all regions except for the Bay of Bengal and the Gulf of Mexico. Our unique and innovative methodology enables globally consistent comparison of TC risk in both time and space and can be easily adapted to accommodate alternative climate scenarios and time periods.

AbstractWater scarcity is a rapidly growing concern around the globe, but little is known about how it has developed over time. This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20th century. Water scarcity is analysed using the fundamental concepts of shortage (impacts due to low availability per capita) and stress (impacts due to high consumption relative to availability) which indicate difficulties in satisfying the needs of a population and overuse of resources respectively. While water consumption increased fourfold within the study period, the population under water scarcity increased from 0.24 billion (14% of global population) in the 1900s to 3.8 billion (58%) in the 2000s. Nearly all sub-national trajectories show an increasing trend in water scarcity. The concept of scarcity trajectory archetypes and shapes is introduced to characterize the historical development of water scarcity and suggest measures for alleviating water scarcity and increasing sustainability. Linking the scarcity trajectories to other datasets may help further deepen understanding of how trajectories relate to historical and future drivers, and hence help tackle these evolving challenges.

The level of public response to extreme catastrophes is considerably greater than concern over climate change. This research compares the public's responses to extreme disasters and climate change when governments intervene to mitigate long-term climate change impacts. To do so we examine the property market behaviour in response to beach erosion and cyclone damage in Queensland, Australia. The results show that the impact on the property market of the public's response to the negative impact of cyclones is more marked than its response to the negative impact of beach erosion. The relative non-responsiveness to beach erosion can be seen as a product of both local government intervention strategies and the recreational and aesthetic attractions of beaches. This study, therefore, provides useful insights for the development of sustainable coastal development strategies.

Empirical evidence of increasing flood damages and the prospect of climatic change has initiated discussions in the flood management community on how to effectively manage flood risks. In the Netherlands, the framework of multi-layer safety (MLS) has been introduced to support this risk-based approach. The MLS framework consists of three layers: (i) prevention, (ii) spatial planning and (iii) evacuation. This paper presents a methodology to evaluate measures in the second layer, such as wet proofing, dry proofing or elevating buildings. The methodology uses detailed land-use data for the area around the city of Rotterdam (up to building level) that has recently become available. The vulnerability of these detailed land-use classes to flooding is assessed using the stage–damage curves from different international models. The methodology is demonstrated using a case study in the unembanked area of Rotterdam in the Netherlands, as measures from the second layer may be particularly effective there. The results show that the flood risk in the region is considerable: EUR 36 million p.a. A large part (almost 60 %) of this risk results from industrial land use, emphasising the need to give this category more attention in flood risk assessments. It was found that building level measures could substantially reduce flood risks in the region because of the relatively low inundation levels of buildings. Risk to residential buildings would be reduced by 40 % if all buildings would be wet-proofed, by 89 % if all buildings would be dry-proofed and elevating buildings over 100 cm would render the risk almost zero. While climate change could double the risk in 2100, such building level measures could easily nullify this effect. Despite the high potential of such measures, actual implementation is still limited. This is partly caused by the lack of knowledge regarding these measures by most Dutch companies and the legal impossibility for municipalities to enforce most of these measures as they would go beyond the building codes established at the national level.

Cost-benefit analysis (CBA) of flood risk adaptation strategies offers policymakers insight into economically optimal strategies for adapting to sea level rise. However, building-level adaptation measures such as floodproofing or building elevation are often evaluated at aggregated spatial scales, which may result in sub-optimal investment decisions. In this paper, we develop a flood risk model and combine it with a micro-scale CBA at the building level to obtain an optimal mix of adaptation measures per area. We apply this approach to Venice Beach in Los Angeles and Naples in Long Beach. We subsequently compare our results with the conventional, spatially aggregated area-based CBA approach. Our findings show that a mix of 35%–45% dry-floodproofing measures and 55%–65% building elevation measures is optimal. Elevation works best in areas with high inundation depths, while dry-floodproofing is preferable in areas with shallow inundation depths. The optimal mix of measures derived from our micro-scale approach results in an economic efficiency up to 85% higher than that yielded by the commonly applied spatially aggregated approach. We therefore recommend that economic evaluations of building-level adaptation measures are conducted at the smallest possible scale, or that CBAs are performed on disaggregated areas based on inundation depth.

Abstract The economic impacts of disasters can reach far beyond the affected regions through interconnected transboundary trade flows. As quantification of these indirect impacts is complex, most disaster risk models focus on the direct impacts on assets and people in the impacted region. This study explicitly includes the indirect effects via regional economic interdependencies to model economic disaster losses on a continental scale, exemplified by river flooding in Europe. The results demonstrate that economic implications go beyond the direct damages typically considered. Moreover, we find that indirect losses can be offset by up to 60% by economic actors through finding alternative suppliers and markets within their existing trade relations. Towards the future, increases in economic flood losses (up to 350%) can be expected for all global warming scenarios. Indirect losses rise by 65% more compared to direct asset damages due to the increasing size of future flood events, making it more difficult to offset losses through alternative suppliers and markets. On a sectoral level, future increases in losses are highest for commercial services (∼980%) and public utilities (∼580%). As the latter are predominately affected through cascading effects, this highlights how interdependencies between economic actors could amplify future disaster losses.