Nov 4, 2016

Defining a new normal for extremes in a warming world

Sophie C. Lewis, Andrew D. King, and Sarah E. Perkins-Kirkpatrick
Bulletin of the American Meteorological Society
  • Defines and applies the term ‘new normal’ to 2015 record-breaking temperatures
  • States that a new normal can be useful for understanding and communicating extremes in a changing climate when precisely defined
  • Provides a formal definition of a new climate normal relative to present based around record-breaking contemporary events and explores the timing of when such extremes become statistically normal in the future model simulations
  • Determines that the 2015 global annual average temperatures will be the new normal by 2040 in all emissions scenarios
  • Finds that at the regional level, a new normal can be delayed through aggressive greenhouse gas emissions reductions