The key to understanding our extended climate forecast may lie in the distant past.

On Tuesday, May 7, at NASA’s Langley Research Center, meteorologist Michael Mann will present, “The Past as Prologue: Learning from the Climate Changes in Past Centuries,” at 2 p.m. in the Reid Conference Center here.

Mann will be available to answer questions from the media during a news briefing at 1:15 p.m. that day. Media who wish to do so should contact Chris Rink at 757-864-6786, or by e-mail at chris.rink@nasa.gov, by noon on the day of the talk for credentials and entry to the center.

That same evening at 7:30, Mann will present, “The Hockey Stick and the Climate Wars: Dispatches from the Front Lines,” for the general public at the Virginia Air & Space Center in downtown Hampton. This Sigma Series event is free and no reservations are required.

At the Langley talk, Mann will review work over the last decade aimed at establishing the nature and factors of large-scale climate variability from the past. He will also discuss recent studies that suggest climate sensitivity may have been underestimated in past studies that compare model simulations and paleoclimate reconstructions.

For the Sigma series presentation, Mann will tell the story behind, “The Hockey Stick” a graph constructed to depict changes in Earth’s temperature in the last 1,000 years. The graph became an icon in the debate over human-caused climate change.