• Energy Research

Until the 1970s, disaster risk was perceived as a direct consequence of natural hazards. Gradually, disaster risk has come to be understood as a compound event, which lies at the intersection of hazards, exposure, and vulnerability of the exposed elements. After decades of research and lessons learned from mega-disasters, social scientists have introduced the social dimension of disaster risk, and the prevailing understanding is that disasters are also a human construct. Now, due to climate and global environmental changes, even the natural component of hazards is being altered by anthropogenic activities, changing hazard susceptibility, coverage, frequency, and severity. This review retraces the brief history and evolution of the global understanding of disaster risk as a compound event, in parallel with research on global environmental change. It highlights the main milestones in this area, and shows that there are tight connections between trends of disaster risk and global change. This paper aims to demonstrate the need to better consider the role of global environmental change in disaster risk assessment. In 2015, three major new agreements were reached to improve global environmental governance: the new Sendai Framework (2015–2030), the post-2015 development agenda with the 17 Sustainable Development Goals (SDGs), and the Climate COP21 in Paris. These all include a clear focus on disaster risk reduction; however, several aspects of disaster risk linked with global environmental changes are still not clearly addressed by the main stakeholders (governments, insurers, or agencies). As the complexity of risk unfolds, more actors are getting together; the need for a holistic approach for disaster risk reduction has become clear, and is closely connected with achieving sustainable development.

A holistic perspective on changing rainfall-driven flood risk is provided for the late 20th and early 21st centuries. Economic losses from floods have greatly increased, principally driven by the expanding exposure of assets at risk. It has not been possible to attribute rain-generated peak streamflow trends to anthropogenic climate change over the past several decades. Projected increases in the frequency and intensity of heavy rainfall, based on climate models, should contribute to increases in precipitation-generated local flooding (e.g. flash flooding and urban flooding). This article assesses the literature included in the IPCC SREX report and new literature published since, and includes an assessment of changes in flood risk in seven of the regions considered in the recent IPCC SREX report—Africa, Asia, Central and South America, Europe, North America, Oceania and Polar regions. Also considering newer publications, this article is consistent with the recent IPCC SREX assessment finding that the impacts of climate change on flood characteristics are highly sensitive to the detailed nature of those changes and that presently we have only low confidence in numerical projections of changes in flood magnitude or frequency resulting from climate change. Hydrological sciences journal, 59 (1) ISSN:0262-6667 ISSN:2150-3435

With climate change, urban development and economic growth, more assets and infrastructures will be exposed to flooding. Now research shows that investments in flood protection are globally beneficial, but have varied levels of benefit locally.