Department Seminar: Leonard Ohenhen

Title: Improving Environmental Security in the Era of Climate Change

Abstract: Climate change is intensifying environmental hazards globally and imposing widespread consequences on human communities and ecosystems. During this century, climate change will cause an increase in the frequency and intensity of heat waves, hurricanes, and wildfires, and severely impact the world's freshwater resources through frequent droughts, alterations in precipitation and evapotranspiration patterns, and sea-level rise (SLR). Among these impacts, SLR is poised to have one of the most profound socioeconomic impacts due to the dense populations, critical infrastructure, and ecosystems situated along coastlines. Global mean sea level has risen by about 17 cm over the past 100 years, however, SLR on local and regional scales are the most relevant for coastal communities. Regional and local SLR are not uniform in space and time and are dependent on vertical land motion (VLM) - the raising or lowering of land. In most coastal communities the risks posed by rising sea levels are recognized, what is often underappreciated is the role of land subsidence (or lowering of land) to exacerbate these hazards. Without incorporating land subsidence into coastal vulnerability assessment, coastal communities may underestimate the environmental threat of rising sea levels, leading to policies that fall short of the required response. This presentation focuses on the use of sophisticated radar satellite data to create high-resolution maps of VLM at mm-level accuracy for the coasts of the United States mainland. I will discuss the impacts of land subsidence as a recognized and an emerging environmental security threat. I will present result of combining land subsidence data with climate change SLR projections to predict areas, people, and properties that will be affected by future flooding hazards in several U.S. coastal cities. The understanding of multi-hazard faced by communities is important to forge a path toward a sustainable future, where communities are shielded from the most severe consequences of environmental hazards in the era of climate change.