Departmental Seminar
February 22, 2018

Hurricanes and Climate Change: Expectations versus Observations

Chris Landsea
National Hurricane Center

Climate variability and any resulting change in the

characteristics of tropical cyclones (tropical storms, subtropical storms, and

hurricanes) have become topics of great interest and research within the

past few years. Some recent scientific articles have reported a large increase

in tropical cyclone energy, numbers, and windspeeds in many basins

during the last few decades in association with warmer sea surface

temperatures. These increases in tropical cyclone activity have been

linked to man-made greenhouse gas changes.


It is not disputed (by this speaker) that anthropogenic forcing has

been the cause of at least a substantial portion of the observed

warming during the 20th Century. It is likely that some increase in

tropical cyclone peak windspeeds has occurred and will continue to

occur if the climate continues to warm. However, whether greenhouse

gas warming is related in increases in tropical cyclone activity is

NOT the most relevant question. One needs to address instead: What is

the SENSITIVITY of tropical cyclone intensity, frequency and overall

activity to greenhouse gas forcing? Is it indeed large today, or is

it likely to be a small factor even several decades from now?

These questions as well as an attempt to reconcile theoretical/numerical

modeling studies with some recent (well publicized) observational

papers will be addressed in the talk. Finally, how these greenhouse

gas warming changes compare versus other alterations in our society

(increased population and infrastructure in vulnerable coastal

locations) will also be discussed.