Joint CSDMS-SEN annual meeting 2016: Capturing Climate Change

From Relative Sea Level Rise to Coastal Risk: Estimating Contemporary and Future Flood Risk in Deltas

Zach Tessler

Environmental CrossRoads Initiative, CUNY Advanced Science Research Center, United States

Deltas are highly sensitive to local human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. In this talk, I’ll discuss a recently developed risk framework for estimating the sensitivity of deltas to relative sea level rise, and the expected impact on flood risk. We apply this framework to an integrated set of global environmental, geophysical, and social indicators over 48 major deltas to quantify how delta flood risk due to extreme events is changing over time. Although geophysical and relative sea-level rise derived risks are distributed across all levels of economic development, wealthy countries effectively limit their present-day threat by gross domestic product–enabled infrastructure and coastal defense investments. However, when investments do not address the long-term drivers of land subsidence and relative sea-level rise, overall risk can be very sensitive to changes in protective capability. For instance, we show how in an energy-constrained future scenario, such protections will probably prove to be unsustainable, raising relative risks by four to eight times in the Mississippi and Rhine deltas and by one-and-a-half to four times in the Chao Phraya and Yangtze deltas. This suggests that the current emphasis on short-term solutions on the world’s deltas will greatly constrain options for designing sustainable solutions in the long term.

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Of interest for:
  • Coastal Working Group
  • Human Dimensions Focus Research Group