Atlantic hurricane surge response to geoengineering.

Area of Science:

• Climate science
• Atmospheric science
• Oceanography

Background:

• Atlantic hurricane-induced floods are rare but intensifying due to rising sea surface temperatures.
• Geoengineering via stratospheric sulfate aerosol injection could potentially mitigate hurricane frequency and intensity.

Purpose of the Study:

• To examine the hypothesis that geoengineering can mitigate Atlantic hurricanes.
• To project changes in storm surge events and coastal flood risk under geoengineering scenarios.

Main Methods:

• Utilized eight earth system model simulations from Geoengineering Model Intercomparison Project (GeoMIP) G3 and G4 schemes.
• Employed a temperature-dependent generalized extreme value statistical model calibrated with historical storm surge and temperature data since 1923.

Main Results:

• Geoengineering significantly ameliorated global and tropical temperature increases under the Representative Concentration Pathway (RCP) 4.5 scenario.
• Projected a ~50% reduction in major storm surge events, though with marginal statistical significance.
• Factored in sea level rise differences, projecting reduced expected flood levels (40 cm for 5-year events, halved for 50-year surges).

Conclusions:

• Stratospheric sulfate aerosol injection shows potential for hurricane mitigation and reduced coastal flood risk.
• Significant sulfate injection levels are required, with implications for stratospheric ozone.
• Geoengineering offers a potential, albeit complex, strategy for managing climate change impacts on Atlantic hurricanes.