How Does Climate Variability and Change Impact Severe Weather?

Greg Holland
NCAR

Societal vulnerability to weather arises largely from relatively rare events at the extremes of the spectrum. Such high-impact weather includes: extended droughts, heat waves, major hurricanes, extreme local rainfall and snowfall, ice storms, European wind storms, and severe local storms and tornadoes. Our vulnerability to property loss and societal disruption also is increasing as society becomes more complex and interconnected, and as private, industrial and commercial development expands in high risk areas. Understanding and predicting variations and changes in weather extremes is thus a major societal issue, encompassing, for example, urban commercial and industrial planning, watershed maintenance and design, insurance types and premiums, and government policy.

As has been emphasized by the IPCC, application of extreme statistics implies that weather extremes should respond strongly to climate variability and change. However, weather extremes also are constrained by available energy together with development capacity and time scale. These physical constraints provide a substantial twist to the purely statistical tail.

In this presentation I discuss the impacts of recent past climate change on current severe weather and where this may project to in the future. I first define climate change by way of a new index. The impact of climate change to current hurricane and temperature extremes is then assessed from both a statistical and physical perspective. This indicates that:

  • Changes to extremes may be initially quite rapid but then reach a saturation beyond which a muted or perhaps even no response occurs
  • Some elements of current extreme weather already contain a strong climate signal; in the case of hurricanes, the bulk of the possible changes may have already occurred.

***PLEASE NOTE THE TIME CHANGE***

Thursday, 9 May 2013, 4:00 PM
Refreshments 3:45 PM
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg 2 Main Auditorium, Room 1022

About the presenter
Presenter(s): 
Greg Holland

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1022

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Thursday, May 9, 2013 - 4:00pm